Many Linux systems are configured to not panic on oops; but allowing an
attacker to oops the system **really** often can make even bugs that look
completely unexploitable exploitable (like NULL dereferences and such) if
each crash elevates a refcount by one or a lock is taken in read mode, and
this causes a counter to eventually overflow.
The most interesting counters for this are 32 bits wide (like open-coded
refcounts that don't use refcount_t). (The ldsem reader count on 32-bit
platforms is just 16 bits, but probably nobody cares about 32-bit platforms
that much nowadays.)
So let's panic the system if the kernel is constantly oopsing.
The speed of oopsing 2^32 times probably depends on several factors, like
how long the stack trace is and which unwinder you're using; an empirically
important one is whether your console is showing a graphical environment or
a text console that oopses will be printed to.
In a quick single-threaded benchmark, it looks like oopsing in a vfork()
child with a very short stack trace only takes ~510 microseconds per run
when a graphical console is active; but switching to a text console that
oopses are printed to slows it down around 87x, to ~45 milliseconds per
run.
(Adding more threads makes this faster, but the actual oops printing
happens under &die_lock on x86, so you can maybe speed this up by a factor
of around 2 and then any further improvement gets eaten up by lock
contention.)
It looks like it would take around 8-12 days to overflow a 32-bit counter
with repeated oopsing on a multi-core X86 system running a graphical
environment; both me (in an X86 VM) and Seth (with a distro kernel on
normal hardware in a standard configuration) got numbers in that ballpark.
12 days aren't *that* short on a desktop system, and you'd likely need much
longer on a typical server system (assuming that people don't run graphical
desktop environments on their servers), and this is a *very* noisy and
violent approach to exploiting the kernel; and it also seems to take orders
of magnitude longer on some machines, probably because stuff like EFI
pstore will slow it down a ton if that's active.
In linux-next, IA64_MCA_RECOVERY uses the (new) function
make_task_dead(), which is not exported for use by modules. Instead of
exporting it for one user, convert IA64_MCA_RECOVERY to be a bool
Kconfig symbol.
In a config file from "kernel test robot <lkp@intel.com>" for a
different problem, this linker error was exposed when
CONFIG_IA64_MCA_RECOVERY=m.
arch/csky/kernel/traps.c: In function 'die':
arch/csky/kernel/traps.c:112:17: error: implicit declaration of function
'make_dead_task' [-Werror=implicit-function-declaration]
112 | make_dead_task(SIGSEGV);
| ^~~~~~~~~~~~~~
The function's name is make_task_dead(), change it so there is no more
build error.
Fixes: 238bcd2dab75 ("exit: Add and use make_task_dead.") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lkml.kernel.org/r/20211227184851.2297759-4-nathan@kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
arch/h8300/kernel/traps.c: In function 'die':
arch/h8300/kernel/traps.c:109:2: error: implicit declaration of function
'make_dead_task' [-Werror=implicit-function-declaration]
109 | make_dead_task(SIGSEGV);
| ^~~~~~~~~~~~~~
arch/h8300/mm/fault.c: In function 'do_page_fault':
arch/h8300/mm/fault.c:54:2: error: implicit declaration of function
'make_dead_task' [-Werror=implicit-function-declaration]
54 | make_dead_task(SIGKILL);
| ^~~~~~~~~~~~~~
The function's name is make_task_dead(), change it so there is no more
build error.
Additionally, include linux/sched/task.h in arch/h8300/kernel/traps.c
to avoid the same error because do_exit()'s declaration is in kernel.h
but make_task_dead()'s is in task.h, which is not included in traps.c.
Fixes: 238bcd2dab75 ("exit: Add and use make_task_dead.") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lkml.kernel.org/r/20211227184851.2297759-3-nathan@kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
arch/hexagon/kernel/traps.c:217:2: error: implicit declaration of
function 'make_dead_task' [-Werror,-Wimplicit-function-declaration]
make_dead_task(err);
^
The function's name is make_task_dead(), change it so there is no more
build error.
Fixes: 238bcd2dab75 ("exit: Add and use make_task_dead.") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lkml.kernel.org/r/20211227184851.2297759-2-nathan@kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Recently the kbuild robot reported two new errors:
>> lib/kunit/kunit-example-test.o: warning: objtool: .text.unlikely: unexpected end of section
>> arch/x86/kernel/dumpstack.o: warning: objtool: oops_end() falls through to next function show_opcodes()
I don't know why they did not occur in my test setup but after digging
it I realized I had accidentally dropped a comma in
tools/objtool/check.c when I renamed rewind_stack_do_exit to
rewind_stack_and_make_dead.
Add that comma back to fix objtool errors.
Link: https://lkml.kernel.org/r/202112140949.Uq5sFKR1-lkp@intel.com Fixes: 238bcd2dab75 ("exit: Add and use make_task_dead.") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
KASAN errors will currently trigger a panic when panic_on_warn is set.
This renders kasan_multishot useless, as further KASAN errors won't be
reported if the kernel has already paniced. By making kasan_multishot
disable this behaviour for KASAN errors, we can still have the benefits of
panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot.
This is particularly important when running KASAN tests, which need to
trigger multiple KASAN errors: previously these would panic the system if
panic_on_warn was set, now they can run (and will panic the system should
non-KASAN warnings show up).
Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Patricia Alfonso <trishalfonso@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Shuah Khan <shuah@kernel.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/20200915035828.570483-6-davidgow@google.com Link: https://lkml.kernel.org/r/20200910070331.3358048-6-davidgow@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
In order to avoid copy-pasting "panic_on_warn = 0" all over the places,
it is better to move it inside panic() and then remove it from the other
places.
Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Xuefeng Li <lixuefeng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Patch series "sysctl: first set of kernel/sysctl cleanups", v2.
Finally had time to respin the series of the work we had started last
year on cleaning up the kernel/sysct.c kitchen sink. People keeps
stuffing their sysctls in that file and this creates a maintenance
burden. So this effort is aimed at placing sysctls where they actually
belong.
I'm going to split patches up into series as there is quite a bit of
work.
This first set adds register_sysctl_init() for uses of registerting a
sysctl on the init path, adds const where missing to a few places,
generalizes common values so to be more easy to share, and starts the
move of a few kernel/sysctl.c out where they belong.
The majority of rework on v2 in this first patch set is 0-day fixes.
Eric Biederman's feedback is later addressed in subsequent patch sets.
I'll only post the first two patch sets for now. We can address the
rest once the first two patch sets get completely reviewed / Acked.
This patch (of 9):
The kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.
To help with this maintenance let's start by moving sysctls to places
where they actually belong. The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.
Today though folks heavily rely on tables on kernel/sysctl.c so they can
easily just extend this table with their needed sysctls. In order to
help users move their sysctls out we need to provide a helper which can
be used during code initialization.
We special-case the initialization use of register_sysctl() since it
*is* safe to fail, given all that sysctls do is provide a dynamic
interface to query or modify at runtime an existing variable. So the
use case of register_sysctl() on init should *not* stop if the sysctls
don't end up getting registered. It would be counter productive to stop
boot if a simple sysctl registration failed.
Provide a helper for init then, and document the recommended init levels
to use for callers of this routine. We will later use this in
subsequent patches to start slimming down kernel/sysctl.c tables and
moving sysctl registration to the code which actually needs these
sysctls.
[mcgrof@kernel.org: major commit log and documentation rephrasing also moved to fs/proc/proc_sysctl.c ]
Link: https://lkml.kernel.org/r/20211123202347.818157-1-mcgrof@kernel.org Link: https://lkml.kernel.org/r/20211123202347.818157-2-mcgrof@kernel.org Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Paul Turner <pjt@google.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Qing Wang <wangqing@vivo.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Stephen Kitt <steve@sk2.org> Cc: Antti Palosaari <crope@iki.fi> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Lukas Middendorf <kernel@tuxforce.de> Cc: Mark Fasheh <mark@fasheh.com> Cc: Phillip Potter <phil@philpotter.co.uk> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: James E.J. Bottomley <jejb@linux.ibm.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
If the function sdma_load_context() fails, the sdma_desc will be
freed, but the allocated desc->bd is forgot to be freed.
We already met the sdma_load_context() failure case and the log as
below:
[ 450.699064] imx-sdma 30bd0000.dma-controller: Timeout waiting for CH0 ready
...
In this case, the desc->bd will not be freed without this change.
The following kernel panic can be triggered when a task with pid=1 attaches
a prog that attempts to send killing signal to itself, also see [1] for more
details:
arch/arm/boot/dts/imx53-ppd.dtb: i2c-switch@70: $nodename:0: 'i2c-switch@70' does not match '^(i2c-?)?mux'
From schema: Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml
arch/arm/boot/dts/imx53-ppd.dtb: i2c-switch@70: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'i2c@0', 'i2c@1', 'i2c@2', 'i2c@3', 'i2c@4', 'i2c@5', 'i2c@6', 'i2c@7' were unexpected)
From schema: Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml
Fix this by renaming the PCA9547 node to "i2c-mux", to match the I2C bus
multiplexer/switch DT bindings and the Generic Names Recommendation in
the Devicetree Specification.
The release function is called with a pointer to the memory returned by
devres_alloc(). I was confused about that by the code before the
generalization that used a struct clk **ptr.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Fixes: 111eac8fbc76 ("clk: generalize devm_clk_get() a bit") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220620171815.114212-1-u.kleine-koenig@pengutronix.de Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The left shift of int 32 bit integer constant 1 is evaluated using 32 bit
arithmetic and then passed as a 64 bit function argument. In the case where
i is 32 or more this can lead to an overflow. Avoid this by shifting
using the BIT_ULL macro instead.
Fixes: dcf8995f1468 ("perf/x86/amd: Constrain Large Increment per Cycle events") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ian Rogers <irogers@google.com> Acked-by: Kim Phillips <kim.phillips@amd.com> Link: https://lore.kernel.org/r/20221202135149.1797974-1-colin.i.king@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An SCTP endpoint can start an association through a path and tear it
down over another one. That means the initial path will not see the
shutdown sequence, and the conntrack entry will remain in ESTABLISHED
state for 5 days.
By merging the HEARTBEAT_ACKED and ESTABLISHED states into one
ESTABLISHED state, there remains no difference between a primary or
secondary path. The timeout for the merged ESTABLISHED state is set to
210 seconds (hb_interval * max_path_retrans + rto_max). So, even if a
path doesn't see the shutdown sequence, it will expire in a reasonable
amount of time.
With this change in place, there is now more than one state from which
we can transition to ESTABLISHED, COOKIE_ECHOED and HEARTBEAT_SENT, so
handle the setting of ASSURED bit whenever a state change has happened
and the new state is ESTABLISHED. Removed the check for dir==REPLY since
the transition to ESTABLISHED can happen only in the reply direction.
Baoquan reported that after triggering a crash the subsequent crash-kernel
fails to boot about half of the time. It triggers a NULL pointer
dereference in the periodic tick code.
This happens because the legacy timer interrupt (IRQ0) is resent in
software which happens in soft interrupt (tasklet) context. In this context
get_irq_regs() returns NULL which leads to the NULL pointer dereference.
The reason for the resend is a spurious APIC interrupt on the IRQ0 vector
which is captured and leads to a resend when the legacy timer interrupt is
enabled. This is wrong because the legacy PIC interrupts are level
triggered and therefore should never be resent in software, but nothing
ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not
know about their trigger type.
Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.
Fixes: 1b9b99027512 ("[PATCH] genirq: add genirq sw IRQ-retrigger") Reported-by: Baoquan He <bhe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Baoquan He <bhe@redhat.com> Link: https://lore.kernel.org/r/87mt6rjrra.ffs@tglx Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Don't use a WARN_ON when printing a potentially user triggered
condition. Also don't print the partno when the block device name
already includes it, and use the %pg specifier to simplify printing
the block device name.
In order to ensure that knfsd threads don't linger once the nfsd
pseudofs is unmounted (e.g. when the container is killed) we let
nfsd_umount() shut down those threads and wait for them to exit.
This also should ensure that we don't need to do a kernel mount of
the pseudofs, since the thread lifetime is now limited by the
lifetime of the filesystem.
This header file is currently included into the ethernet driver via a
relative path into the PHY subsystem. This is bad practice, and causes
issues for the upcoming move of the MDIO driver. Move the header file
into include/linux to clean this up.
v2:
Move header to include/linux/mdio
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7083df59abbc ("net: mdio-mux-meson-g12a: force internal PHY off on mux switch") Signed-off-by: Sasha Levin <sashal@kernel.org>
In preparation for moving all MDIO drivers into drivers/net/mdio, move
the mdio-i2c header file into include/linux/mdio so it can be used by
both the MDIO driver and the SFP code which instantiates I2C MDIO
busses.
v2:
Add include/linux/mdio
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7083df59abbc ("net: mdio-mux-meson-g12a: force internal PHY off on mux switch") Signed-off-by: Sasha Levin <sashal@kernel.org>
During EEH error injection testing, a deadlock was encountered in the tg3
driver when tg3_io_error_detected() was attempting to cancel outstanding
reset tasks:
Code inspection shows that both tg3_io_error_detected() and
tg3_reset_task() attempt to acquire the RTNL lock at the beginning of
their code blocks. If tg3_reset_task() should happen to execute between
the times when tg3_io_error_deteced() acquires the RTNL lock and
tg3_reset_task_cancel() is called, a deadlock will occur.
Moving tg3_reset_task_cancel() call earlier within the code block, prior
to acquiring RTNL, prevents this from happening, but also exposes another
deadlock issue where tg3_reset_task() may execute AFTER
tg3_io_error_detected() has executed:
In order to prevent int340x_thermal_get_trip_type() from possibly
racing with int340x_thermal_read_trips() invoked by int3403_notify()
add locking to it in analogy with int340x_thermal_get_trip_temp().
Fixes: 6757a7abe47b ("thermal: intel: int340x: Protect trip temperature from concurrent updates") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Since this driver enables the interrupt by RIC2_QFE1, this driver
should clear the interrupt flag if it happens. Otherwise, the interrupt
causes to hang the system.
Note that this also fix a minor coding style (a comment indentation)
around the fixed code.
Fixes: a6c893cbad16 ("Renesas Ethernet AVB driver proper") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently, if you bind the socket to something like:
servaddr.sin6_family = AF_INET6;
servaddr.sin6_port = htons(0);
servaddr.sin6_scope_id = 0;
inet_pton(AF_INET6, "::1", &servaddr.sin6_addr);
And then request a connect to:
connaddr.sin6_family = AF_INET6;
connaddr.sin6_port = htons(20000);
connaddr.sin6_scope_id = if_nametoindex("lo");
inet_pton(AF_INET6, "fe88::1", &connaddr.sin6_addr);
What the stack does is:
- bind the socket
- create a new asoc
- to handle the connect
- copy the addresses that can be used for the given scope
- try to connect
But the copy returns 0 addresses, and the effect is that it ends up
trying to connect as if the socket wasn't bound, which is not the
desired behavior. This unexpected behavior also allows KASLR leaks
through SCTP diag interface.
The fix here then is, if when trying to copy the addresses that can
be used for the scope used in connect() it returns 0 addresses, bail
out. This is what TCP does with a similar reproducer.
syzbot reported a use-after-free in do_accept(), precisely nr_accept()
as sk_prot_alloc() allocated the memory and sock_put() frees it. [0]
The issue could happen if the heartbeat timer is fired and
nr_heartbeat_expiry() calls nr_destroy_socket(), where a socket
has SOCK_DESTROY or a listening socket has SOCK_DEAD.
In this case, the first condition cannot be true. SOCK_DESTROY is
flagged in nr_release() only when the file descriptor is close()d,
but accept() is being called for the listening socket, so the second
condition must be true.
Usually, the AF_NETROM listener neither starts timers nor sets
SOCK_DEAD. However, the condition is met if connect() fails before
listen(). connect() starts the t1 timer and heartbeat timer, and
t1timer calls nr_disconnect() when timeout happens. Then, SOCK_DEAD
is set, and if we call listen(), the heartbeat timer calls
nr_destroy_socket().
This path seems expected, and nr_destroy_socket() is called to clean
up resources. Initially, there was sock_hold() before nr_destroy_socket()
so that the socket would not be freed, but the commit e560caa16cfb
("netrom: Decrease sock refcount when sock timers expire") accidentally
removed it.
To fix use-after-free, let's add sock_hold().
[0]:
BUG: KASAN: use-after-free in do_accept+0x483/0x510 net/socket.c:1848
Read of size 8 at addr ffff88807978d398 by task syz-executor.3/5315
RFC 9260, Sec 8.5.1 states that for ABORT/SHUTDOWN_COMPLETE, the chunk
MUST be accepted if the vtag of the packet matches its own tag and the
T bit is not set OR if it is set to its peer's vtag and the T bit is set
in chunk flags. Otherwise the packet MUST be silently dropped.
Update vtag verification for ABORT/SHUTDOWN_COMPLETE based on the above
description.
if (!type)
continue;
if (type > RTAX_MAX)
return false;
...
fi_val = fi->fib_metrics->metrics[type - 1];
@type being used as an array index, we need to prevent
cpu speculation or risk leaking kernel memory content.
Fixes: d0e08e34fcac ("ipv4: do metrics match when looking up and deleting a route") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230120133140.3624204-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
syzbot reminds us netlink_getname() runs locklessly [1]
This first patch annotates the race against nlk->portid.
Following patches take care of the remaining races.
[1]
BUG: KCSAN: data-race in netlink_getname / netlink_insert
write to 0xffff88814176d310 of 4 bytes by task 2315 on cpu 1:
netlink_insert+0xf1/0x9a0 net/netlink/af_netlink.c:583
netlink_autobind+0xae/0x180 net/netlink/af_netlink.c:856
netlink_sendmsg+0x444/0x760 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
____sys_sendmsg+0x38f/0x500 net/socket.c:2476
___sys_sendmsg net/socket.c:2530 [inline]
__sys_sendmsg+0x19a/0x230 net/socket.c:2559
__do_sys_sendmsg net/socket.c:2568 [inline]
__se_sys_sendmsg net/socket.c:2566 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2566
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffff88814176d310 of 4 bytes by task 2316 on cpu 0:
netlink_getname+0xcd/0x1a0 net/netlink/af_netlink.c:1144
__sys_getsockname+0x11d/0x1b0 net/socket.c:2026
__do_sys_getsockname net/socket.c:2041 [inline]
__se_sys_getsockname net/socket.c:2038 [inline]
__x64_sys_getsockname+0x3e/0x50 net/socket.c:2038
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x00000000 -> 0xc9a49780
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2316 Comm: syz-executor.2 Not tainted 6.2.0-rc3-syzkaller-00030-ge8f60cd7db24-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Skip interference with an ongoing transaction, do not perform garbage
collection on inactive elements. Reset annotated previous end interval
if the expired element is marked as busy (control plane removed the
element right before expiration).
If net_assign_generic() fails, the current error path in ops_init() tries
to clear the gen pointer slot. Anyway, in such error path, the gen pointer
itself has not been modified yet, and the existing and accessed one is
smaller than the accessed index, causing an out-of-bounds error:
BUG: KASAN: slab-out-of-bounds in ops_init+0x2de/0x320
Write of size 8 at addr ffff888109124978 by task modprobe/1018
Most netlink attributes are parsed and validated from
__nla_validate_parse() or validate_nla()
u16 type = nla_type(nla);
if (type == 0 || type > maxtype) {
/* error or continue */
}
@type is then used as an array index and can be used
as a Spectre v1 gadget.
array_index_nospec() can be used to prevent leaking
content of kernel memory to malicious users.
This should take care of vast majority of netlink uses,
but an audit is needed to take care of others where
validation is not yet centralized in core netlink functions.
The memory for llcc_driv_data is allocated by the LLCC driver. But when
it is passed as the private driver info to the EDAC core, it will get freed
during the qcom_edac driver release. So when the qcom_edac driver gets probed
again, it will try to use the freed data leading to the use-after-free bug.
Hence, do not pass llcc_driv_data as pvt_info but rather reference it
using the platform_data pointer in the qcom_edac driver.
zero_page is a void* pointer but memblock_alloc() returns phys_addr_t type
so this generates a warning while using clang and with -Wint-error enabled
that becomes and error. So let's cast the return of memblock_alloc() to
(void *).
Trip temperatures are read using ACPI methods and stored in the memory
during zone initializtion and when the firmware sends a notification for
change. This trip temperature is returned when the thermal core calls via
callback get_trip_temp().
But it is possible that while updating the memory copy of the trips when
the firmware sends a notification for change, thermal core is reading the
trip temperature via the callback get_trip_temp(). This may return invalid
trip temperature.
To address this add a mutex to protect the invalid temperature reads in
the callback get_trip_temp() and int340x_thermal_read_trips().
Fixes: c6f47ab05910 ("Thermal/int340x: Add common thermal zone handler") Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: 5.0+ <stable@vger.kernel.org> # 5.0+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When serializing and deserializing kvm_sregs, attributes of the segment
descriptors are stored by user space. For unusable segments,
vmx_segment_access_rights skips all attributes and sets them to 0.
This means we zero out the DPL (Descriptor Privilege Level) for unusable
entries.
Unusable segments are - contrary to their name - usable in 64bit mode and
are used by guests to for example create a linear map through the
NULL selector.
VMENTER checks if SS.DPL is correct depending on the CS segment type.
For types 9 (Execute Only) and 11 (Execute Read), CS.DPL must be equal to
SS.DPL [1].
We have seen real world guests setting CS to a usable segment with DPL=3
and SS to an unusable segment with DPL=3. Once we go through an sregs
get/set cycle, SS.DPL turns to 0. This causes the virtual machine to crash
reproducibly.
This commit changes the attribute logic to always preserve attributes for
unusable segments. According to [2] SS.DPL is always saved on VM exits,
regardless of the unusable bit so user space applications should have saved
the information on serialization correctly.
[3] specifies that besides SS.DPL the rest of the attributes of the
descriptors are undefined after VM entry if unusable bit is set. So, there
should be no harm in setting them all to the previous state.
In smbd_destroy(), clear the server->smbd_conn pointer after freeing the
smbd_connection struct that it points to so that reconnection doesn't get
confused.
Fixes: 2cb924bb40fd ("CIFS: SMBD: Implement function to destroy a SMB Direct connection") Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Acked-by: Tom Talpey <tom@talpey.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Long Li <longli@microsoft.com> Cc: Pavel Shilovsky <piastryyy@gmail.com> Cc: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The instructions for the ftrace-bisect.sh script, which is used to find
what function is being traced that is causing a kernel crash, and possibly
a triple fault reboot, uses the old method. In 5.1, a new feature was
added that let the user write in the index into available_filter_functions
that maps to the function a user wants to set in set_ftrace_filter (or
set_ftrace_notrace). This takes O(1) to set, as suppose to writing a
function name, which takes O(n) (where n is the number of functions in
available_filter_functions).
The ftrace-bisect.sh requires setting half of the functions in
available_filter_functions, which is O(n^2) using the name method to enable
and can take several minutes to complete. The number method is O(n) which
takes less than a second to complete. Using the number method for any
kernel 5.1 and after is the proper way to do the bisect.
Update the usage to reflect the new change, as well as using the
/sys/kernel/tracing path instead of the obsolete debugfs path.
Link: https://lkml.kernel.org/r/20230123112252.022003dd@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Fixes: a75673e3593b4 ("ftrace: Allow enabling of filters via index of available_filter_functions") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Function 'create_hist_field' is called recursively at
trace_events_hist.c:1954 and can return NULL-value that's why we have
to check it to avoid null pointer dereference.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru Cc: stable@vger.kernel.org Fixes: 6ac0075044a9 ("tracing: Add variable support to hist triggers") Signed-off-by: Natalia Petrova <n.petrova@fintech.ru> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently trace_printk() can be used as soon as early_trace_init() is
called from start_kernel(). But if a crash happens, and
"ftrace_dump_on_oops" is set on the kernel command line, all you get will
be:
[ 0.456075] <idle>-0 0dN.2. 347519us : Unknown type 6
[ 0.456075] <idle>-0 0dN.2. 353141us : Unknown type 6
[ 0.456075] <idle>-0 0dN.2. 358684us : Unknown type 6
This is because the trace_printk() event (type 6) hasn't been registered
yet. That gets done via an early_initcall(), which may be early, but not
early enough.
Instead of registering the trace_printk() event (and other ftrace events,
which are not trace events) via an early_initcall(), have them registered at
the same time that trace_printk() can be used. This way, if there is a
crash before early_initcall(), then the trace_printk()s will actually be
useful.
Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 546b9546f5307 ("tracing: Split tracing initialization into two for early initialization") Reported-by: "Joel Fernandes (Google)" <joel@joelfernandes.org> Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During a system boot, it can happen that the kernel receives a burst of
requests to insert the same module but loading it eventually fails
during its init call. For instance, udev can make a request to insert
a frequency module for each individual CPU when another frequency module
is already loaded which causes the init function of the new module to
return an error.
Since commit 44dfd5c6e62d ("kernel/module.c: Only return -EEXIST for
modules that have finished loading"), the kernel waits for modules in
MODULE_STATE_GOING state to finish unloading before making another
attempt to load the same module.
This creates unnecessary work in the described scenario and delays the
boot. In the worst case, it can prevent udev from loading drivers for
other devices and might cause timeouts of services waiting on them and
subsequently a failed boot.
This patch attempts a different solution for the problem 44dfd5c6e62d
was trying to solve. Rather than waiting for the unloading to complete,
it returns a different error code (-EBUSY) for modules in the GOING
state. This should avoid the error situation that was described in 44dfd5c6e62d (user space attempting to load a dependent module because
the -EEXIST error code would suggest to user space that the first module
had been loaded successfully), while avoiding the delay situation too.
This has been tested on linux-next since December 2022 and passes
all kmod selftests except test 0009 with module compression enabled
but it has been confirmed that this issue has existed and has gone
unnoticed since prior to this commit and can also be reproduced without
module compression with a simple usleep(5000000) on tools/modprobe.c [0].
These failures are caused by hitting the kernel mod_concurrent_max and can
happen either due to a self inflicted kernel module auto-loead DoS somehow
or on a system with large CPU count and each CPU count incorrectly triggering
many module auto-loads. Both of those issues need to be fixed in-kernel.
Fixes: 44dfd5c6e62d ("kernel/module.c: Only return -EEXIST for modules that have finished loading") Co-developed-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Petr Mladek <pmladek@suse.com>
[mcgrof: enhance commit log with testing and kmod test result interpretation ] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'h' is a pointer to struct ctlr_info, so it's just 4 or 8 bytes, while
the structure itself is much bigger.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: ef421ae82373 ("hpsa: add driver for HP Smart Array controllers.") Link: https://lore.kernel.org/r/20230118031255.GE15213@altlinux.org Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org> Acked-by: Don Brace <don.brace@microchip.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Since the commit 6130f167d73b ("VFS: Don't use save/replace_mount_options
if not using generic_show_options") eliminates replace_mount_options
in reiserfs_remount, but does not handle the allocated new_opts,
it will cause memory leak in the reiserfs_remount.
Because new_opts is useless in reiserfs_mount, so we fix this bug by
removing the useless new_opts in reiserfs_remount.
Fixes: 6130f167d73b ("VFS: Don't use save/replace_mount_options if not using generic_show_options") Link: https://lore.kernel.org/r/20211027143445.4156459-1-mudongliangabcd@gmail.com Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
client sends a SYN, but $Host is unreachable/silent.
Client eventually gives up and the conntrack entry will time out.
However, if the client is restarted with same addr/port pair, it
may prevent the conntrack entry from timing out.
This is noticeable when the existing conntrack entry has no NAT
transformation or an outdated one and port reuse happens either
on client or due to a NAT middlebox.
This change prevents refresh of the timeout for SYN retransmits,
so entry is going away after nf_conntrack_tcp_timeout_syn_sent
seconds (default: 60).
Entry will be re-created on next connection attempt, but then
nat rules will be evaluated again.
In current code, we add 1ms dealy after each tuning command for standard
tuning method. Adding this 1ms dealy is because USDHC default check the
CMD CRC and DATA line. If detect the CMD CRC, USDHC standard tuning
IC logic do not wait for the tuning data sending out by the card, trigger
the buffer read ready interrupt immediately, and step to next cycle. So
when next time the new tuning command send out by USDHC, card may still
not send out the tuning data of the upper command，then some eMMC cards
may stuck, can't response to any command, block the whole tuning procedure.
If do not check the CMD CRC for tuning, then do not has this issue. USDHC
will wait for the tuning data of each tuning command and check them. If the
tuning data pass the check, it also means the CMD line also okay for tuning.
So this patch disable the CMD CRC check for tuning, save some time for the
whole tuning procedure.
On i.MX8MM, we are running Dual Linux OS, with 1st Linux using SD Card
as rootfs storage, 2nd Linux using eMMC as rootfs storage. We let the
the 1st linux configure power/clock for the 2nd Linux.
When the 2nd Linux is booting into rootfs stage, we let the 1st Linux
to destroy the 2nd linux, then restart the 2nd linux, we met SDHCI dump
as following, after we clear the pending interrupt and halt CQCTL, issue
gone.
On the x86-64 architecture even a failing cmpxchg grants exclusive
access to the cacheline, making it preferable to retry the failed op
immediately instead of stalling with the pause instruction.
To illustrate the impact, below are benchmark results obtained by
running various will-it-scale tests on top of the 6.2-rc3 kernel and
Cascade Lake (2 sockets * 24 cores * 2 threads) CPU.
All results in ops/s. Note there is some variance in re-runs, but the
code is consistently faster when contention is present.
That is, fixing the problems in access itself *reduces* scalability
after the cacheline ping-pong only happens in lockref with the pause
instruction.
Note that fstat and access benchmarks are not currently integrated into
will-it-scale, but interested parties can find them in pull requests to
said project.
Code at hand has a rather tortured history. First modification showed
up in commit ea82cc601b2b ("lockref: Relax in cmpxchg loop"), written
with Itanium in mind. Later it got patched up to use an arch-dependent
macro to stop doing it on s390 where it caused a significant regression.
Said macro had undergone revisions and was ultimately eliminated later,
going back to cpu_relax.
While I intended to only remove cpu_relax for x86-64, I got the
following comment from Linus:
I would actually prefer just removing it entirely and see if
somebody else hollers. You have the numbers to prove it hurts on
real hardware, and I don't think we have any numbers to the
contrary.
So I think it's better to trust the numbers and remove it as a
failure, than say "let's just remove it on x86-64 and leave
everybody else with the potentially broken code"
Additionally, Will Deacon (maintainer of the arm64 port, one of the
architectures previously benchmarked):
So, from the arm64 side of the fence, I'm perfectly happy just
removing the cpu_relax() calls from lockref.
As such, come back full circle in history and whack it altogether.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/all/CAGudoHHx0Nqg6DE70zAVA75eV-HXfWyhVMWZ-aSeOofkA_=WdA@mail.gmail.com/ Acked-by: Tony Luck <tony.luck@intel.com> # ia64 Acked-by: Nicholas Piggin <npiggin@gmail.com> # powerpc Acked-by: Will Deacon <will@kernel.org> # arm64 Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently the driver sets the port invalid if one phy in the port is not
enabled, which may cause issues in expander situation. In directly attached
situation, if phy up doesn't occur in time when refreshing port id, the
port is incorrectly set to invalid which will also cause disk lost.
Therefore set a port invalid only if there are no devices attached to the
port.
The two debug messages in spidev_open() dereference spidev->spi without
taking the lock and without checking if it's not null. This can lead to
a crash. Drop the messages as they're not needed - the user-space will
get informed about ENOMEM with the syscall return value.
The fsl-asoc-card AC'97 support currently tries to route to Playback and
Capture widgets provided by the AC'97 CODEC. This doesn't work since the
generic AC'97 driver registers with an "AC97" at the front of the stream
and hence widget names, update to reflect reality. It's not clear to me
if or how this ever worked.
The SSI driver calls the AC'97 playback and transmit streams "AC97 Playback"
and "AC97 Capture" respectively. This is the same name used by the generic
AC'97 CODEC driver in ASoC, creating confusion for the Freescale ASoC card
when it attempts to use these widgets in routing. Add a "CPU" in the name
like the regular DAIs registered by the driver to disambiguate.
Use NULL for NULL pointer to fix the following sparse warning:
drivers/cpufreq/armada-37xx-cpufreq.c:448:32: sparse: warning: Using plain integer as NULL pointer
Using DEBUG_H without a prefix is very generic and inconsistent with
other header guards in arch/s390/include/asm. In fact it collides with
the same name in the ath9k wireless driver though that depends on !S390
via disabled wireless support. Let's just use a consistent header guard
name and prevent possible future trouble.
The parameter "max" of SOC_SINGLE_SX_TLV() means the number of steps
rather than maximum value. This patch corrects the minimum value to -8
and the number of steps to 15.
Tegra234 platform uses the tegra194-cpufreq driver, so add it
to the blocklist in cpufreq-dt-platdev driver to avoid the cpufreq
driver registration from there.
The initial default value of 0 for tp->rate_app_limited was incorrect,
since a flow is indeed application-limited until it first sends
data. Fixing the default to be 1 is generally correct but also
specifically will help user-space applications avoid using the initial
tcpi_delivery_rate value of 0 that persists until the connection has
some non-zero bandwidth sample.
Fixes: fb6af1550f24 ("tcp: export data delivery rate") Suggested-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David Morley <morleyd@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Tested-by: David Morley <morleyd@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
ALU table entry 2 register in KSZ9477 have bit positions reserved for
forwarding port map. This field is referred in ksz9477_fdb_del() for
clearing forward port map and alu table.
But current fdb_del refer ALU table entry 3 register for accessing forward
port map. Update ksz9477_fdb_del() to get forward port map from correct
alu table entry register.
With this bug, issue can be observed while deleting static MAC entries.
Delete any specific MAC entry using "bridge fdb del" command. This should
clear all the specified MAC entries. But it is observed that entries with
self static alone are retained.
Tested on LAN9370 EVB since ksz9477_fdb_del() is used common across
LAN937x and KSZ series.
Fixes: 93279a8384af ("dsa: add DSA switch driver for Microchip KSZ9477") Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@microchip.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Link: https://lore.kernel.org/r/20230118174735.702377-1-rakesh.sankaranarayanan@microchip.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
In test_async_probe_init, second set of asynchronous devices are saved
in sync_dev[sync_id], which should be async_dev[async_id].
This makes these devices not unregistered when exit.
> modprobe test_async_driver_probe && \
> modprobe -r test_async_driver_probe && \
> modprobe test_async_driver_probe
...
> sysfs: cannot create duplicate filename '/devices/platform/test_async_driver.4'
> kobject_add_internal failed for test_async_driver.4 with -EEXIST,
don't try to register things with the same name in the same directory.
Fixes: 17a51946cfeb ("driver core: Rewrite test_async_driver_probe to cover serialization and NUMA affinity") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Link: https://lore.kernel.org/r/20221125063541.241328-1-chenzhongjin@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
I got the following WARNING message while removing driver(ds2482):
------------[ cut here ]------------
do not call blocking ops when !TASK_RUNNING; state=1 set at [<000000002d50bfb6>] w1_process+0x9e/0x1d0 [wire]
WARNING: CPU: 0 PID: 262 at kernel/sched/core.c:9817 __might_sleep+0x98/0xa0
CPU: 0 PID: 262 Comm: w1_bus_master1 Tainted: G N 6.1.0-rc3+ #307
RIP: 0010:__might_sleep+0x98/0xa0
Call Trace:
exit_signals+0x6c/0x550
do_exit+0x2b4/0x17e0
kthread_exit+0x52/0x60
kthread+0x16d/0x1e0
ret_from_fork+0x1f/0x30
The state of task is set to TASK_INTERRUPTIBLE in loop in w1_process(),
set it to TASK_RUNNING when it breaks out of the loop to avoid the
warning.
I got a deadloop report while doing device(ds2482) add/remove test:
[ 162.241881] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
[ 163.272251] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
[ 164.296157] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1.
...
__w1_remove_master_device() can't return, because the dev->refcnt is not zero.
w1_add_master_device() |
w1_alloc_dev() |
atomic_set(&dev->refcnt, 2) |
kthread_run() |
|__w1_remove_master_device()
| kthread_stop()
// KTHREAD_SHOULD_STOP is set, |
// threadfn(w1_process) won't be |
// called. |
kthread() |
| // refcnt will never be 0, it's deadloop.
| while (atomic_read(&dev->refcnt)) {...}
After calling w1_add_master_device(), w1_process() is not really
invoked, before w1_process() starting, if kthread_stop() is called
in __w1_remove_master_device(), w1_process() will never be called,
the refcnt can not be decreased, then it causes deadloop in remove
function because of non-zero refcnt.
We need to make sure w1_process() is really started, so move the
set refcnt into w1_process() to fix this problem.
While one cpu is working on looking up the right socket from ehash
table, another cpu is done deleting the request socket and is about
to add (or is adding) the big socket from the table. It means that
we could miss both of them, even though it has little chance.
Let me draw a call trace map of the server side.
CPU 0 CPU 1
----- -----
tcp_v4_rcv() syn_recv_sock()
inet_ehash_insert()
-> sk_nulls_del_node_init_rcu(osk)
__inet_lookup_established()
-> __sk_nulls_add_node_rcu(sk, list)
Notice that the CPU 0 is receiving the data after the final ack
during 3-way shakehands and CPU 1 is still handling the final ack.
Why could this be a real problem?
This case is happening only when the final ack and the first data
receiving by different CPUs. Then the server receiving data with
ACK flag tries to search one proper established socket from ehash
table, but apparently it fails as my map shows above. After that,
the server fetches a listener socket and then sends a RST because
it finds a ACK flag in the skb (data), which obeys RST definition
in RFC 793.
Besides, Eric pointed out there's one more race condition where it
handles tw socket hashdance. Only by adding to the tail of the list
before deleting the old one can we avoid the race if the reader has
already begun the bucket traversal and it would possibly miss the head.
Many thanks to Eric for great help from beginning to end.
Add missing cleanup in devm_platform_ioremap_resource().
When probe fails remove dma channel resources and disable clocks in
accordance with the order of resources allocated .
Signed-off-by: Swati Agarwal <swati.agarwal@xilinx.com> Link: https://lore.kernel.org/r/20220817061125.4720-2-swati.agarwal@xilinx.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Stable-dep-of: 596b53ccc36a ("dmaengine: xilinx_dma: call of_node_put() when breaking out of for_each_child_of_node()") Signed-off-by: Sasha Levin <sashal@kernel.org>
Replace the chain of platform_get_resource() and devm_ioremap_resource()
with devm_platform_ioremap_resource(). It simplifies the flow and there
is no functional change.
Fixes below cocinelle warning-
WARNING: Use devm_platform_ioremap_resource for xdev -> regs
betopff_init() only checks the total sum of the report counts for each
report field to be at least 4, but hid_betopff_play() expects 4 report
fields.
A device advertising an output report with one field and 4 report counts
would pass the check but crash the kernel with a NULL pointer dereference
in hid_betopff_play().
PTP TX timestamp handling was observed to be broken with this driver
when using the raw Layer 2 PTP encapsulation. ptp4l was not receiving
the expected TX timestamp after transmitting a packet, causing it to
enter a failure state.
The problem appears to be due to the way that the driver pads packets
which are smaller than the Ethernet minimum of 60 bytes. If headroom
space was available in the SKB, this caused the driver to move the data
back to utilize it. However, this appears to cause other data references
in the SKB to become inconsistent. In particular, this caused the
ptp_one_step_sync function to later (in the TX completion path) falsely
detect the packet as a one-step SYNC packet, even when it was not, which
caused the TX timestamp to not be processed when it should be.
Using the headroom for this purpose seems like an unnecessary complexity
as this is not a hot path in the driver, and in most cases it appears
that there is sufficient tailroom to not require using the headroom
anyway. Remove this usage of headroom to prevent this inconsistency from
occurring and causing other problems.
Fixes: af5d7e7c9a45 ("net: macb: add support for padding and fcs computation") Signed-off-by: Robert Hancock <robert.hancock@calian.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com> # on SAMA7G5 Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
The first time dma_chan_get() is called for a channel the channel
client_count is incorrectly incremented twice for public channels,
first in balance_ref_count(), and again prior to returning. This
results in an incorrect client count which will lead to the
channel resources not being freed when they should be. A simple
test of repeated module load and unload of async_tx on a Dell
Power Edge R7425 also shows this resulting in a kref underflow
warning.
cat /sys/class/dma/dma0chan*/in_use would get the wrong result.
2
2
2
Fixes: 97924ec67a1d ("dmaengine: Rework dma_chan_get") Signed-off-by: Koba Ko <koba.ko@canonical.com> Reviewed-by: Jie Hai <haijie1@huawei.com> Test-by: Jie Hai <haijie1@huawei.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Joel Savitz <jsavitz@redhat.com> Link: https://lore.kernel.org/r/20221201030050.978595-1-koba.ko@canonical.com Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.
Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.
As per the documentation, function usb_ep_free_request guarantees
the request will not be queued or no longer be re-queued (or
otherwise used). However, with the current implementation it
doesn't make sure that the request in ep0 isn't reused.
Fix this by dequeuing the ep0req on functionfs_unbind before
freeing the request to align with the definition.
While performing fast composition switch, there is a possibility that the
process of ffs_ep0_write/ffs_ep0_read get into a race condition
due to ep0req being freed up from functionfs_unbind.
Consider the scenario that the ffs_ep0_write calls the ffs_ep0_queue_wait
by taking a lock &ffs->ev.waitq.lock. However, the functionfs_unbind isn't
bounded so it can go ahead and mark the ep0req to NULL, and since there
is no NULL check in ffs_ep0_queue_wait we will end up in use-after-free.
Fix this by making a serialized execution between the two functions using
a mutex_lock(ffs->mutex).
This partially reverts commit 1e91e825c71b58 ("HID: usbhid: Add ALWAYS_POLL quirk
for some mice"), as it turns out to break reboot on some platforms for reason
yet to be understood.
Fixes: 1e91e825c71b58 ("HID: usbhid: Add ALWAYS_POLL quirk for some mice") Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
In a number of cases the driver assigns a default value of -1 to
priv->plat->phy_addr. This may result in calling mdiobus_get_phy()
with addr parameter being -1. Therefore check for this scenario and
bail out before calling mdiobus_get_phy().
Fixes: e08a56c85e3d ("net: stmmac: Fix case when PHY handle is not present") Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Link: https://lore.kernel.org/r/669f9671-ecd1-a41b-2727-7b73e3003985@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Add a check for empty report_list in bigben_probe().
The missing check causes a type confusion when issuing a list_entry()
on an empty report_list.
The problem is caused by the assumption that the device must
have valid report_list. While this will be true for all normal HID
devices, a suitably malicious device can violate the assumption.
Add a check for empty report_list in hid_validate_values().
The missing check causes a type confusion when issuing a list_entry()
on an empty report_list.
The problem is caused by the assumption that the device must
have valid report_list. While this will be true for all normal HID
devices, a suitably malicious device can violate the assumption.
Fixes: d94b10af9775 ("HID: core: fix validation of report id 0") Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
The caller may pass any value as addr, what may result in an out-of-bounds
access to array mdio_map. One existing case is stmmac_init_phy() that
may pass -1 as addr. Therefore validate addr before using it.
Fixes: 4c73cde247d0 ("phy: Add API for {un}registering an mdio device to a bus.") Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/cdf664ea-3312-e915-73f8-021678d08887@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Packet len computed as difference of length word extracted from
skb data and four may result in a negative value. In such case
processing of the buffer should be interrupted rather than
setting sr_skb->len to an unexpectedly large value (due to cast
from signed to unsigned integer) and passing sr_skb to
usbnet_skb_return.
When holding a reader-writer spin lock we cannot sleep. Calling
setup_udp_tunnel_sock() with write lock held violates this rule, because we
end up calling percpu_down_read(), which might sleep, as syzbot reports
[1]:
Trim the writer-side critical section for sk_callback_lock down to the
minimum, so that it covers only operations on sk_user_data.
Also, when grabbing the sk_callback_lock, we always need to disable BH, as
Eric points out. Failing to do so leads to deadlocks because we acquire
sk_callback_lock in softirq context, which can get stuck waiting on us if:
v2:
- Check and set sk_user_data while holding sk_callback_lock for both
L2TP encapsulation types (IP and UDP) (Tetsuo)
Cc: Tom Parkin <tparkin@katalix.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Fixes: 6e77507cc06b ("l2tp: Serialize access to sk_user_data with sk_callback_lock") Reported-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+703d9e154b3b58277261@syzkaller.appspotmail.com Reported-by: syzbot+50680ced9e98a61f7698@syzkaller.appspotmail.com Reported-by: syzbot+de987172bb74a381879b@syzkaller.appspotmail.com Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
sk->sk_user_data has multiple users, which are not compatible with each
other. Writers must synchronize by grabbing the sk->sk_callback_lock.
l2tp currently fails to grab the lock when modifying the underlying tunnel
socket fields. Fix it by adding appropriate locking.
We err on the side of safety and grab the sk_callback_lock also inside the
sk_destruct callback overridden by l2tp, even though there should be no
refs allowing access to the sock at the time when sk_destruct gets called.
v4:
- serialize write to sk_user_data in l2tp sk_destruct
v3:
- switch from sock lock to sk_callback_lock
- document write-protection for sk_user_data
v2:
- update Fixes to point to origin of the bug
- use real names in Reported/Tested-by tags
Cc: Tom Parkin <tparkin@katalix.com> Fixes: 72ecdb28cfd7 ("[L2TP]: PPP over L2TP driver core") Reported-by: Haowei Yan <g1042620637@gmail.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
l2tp_tunnel_register() registers a tunnel without fully
initializing its attribute. This can allow another kernel thread
running l2tp_xmit_core() to access the uninitialized data and
then cause a kernel NULL pointer dereference error, as shown below.
Fix this bug by initializing tunnel->sock before adding the
tunnel into l2tp_tunnel_list.
Reviewed-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Sishuai Gong <sishuai@purdue.edu> Reported-by: Sishuai Gong <sishuai@purdue.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 6.0.0-rc2-syzkaller-47461-gac3859c02d7f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Fixes: 6e8a93ac1aec ("tc: Add support for configuring the taprio scheduler") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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