]> git.baikalelectronics.ru Git - kernel.git/commit
iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE)
authorAlexander Lobakin <alexandr.lobakin@intel.com>
Tue, 12 Jul 2022 15:38:36 +0000 (17:38 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Aug 2022 09:18:15 +0000 (11:18 +0200)
commit3948498e6ddbeb6b2b131574aa040dcb57d664c6
treea1d450dcdfddea21e9fe07300b8e9cbf5bce1735
parenta4b78b35ed980d58e193f635dacb00479a710025
iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE)

commit 8ae302e31684b46497b83b06f99feafa40ed3f9b upstream.

KASAN reports:

[ 4.668325][ T0] BUG: KASAN: wild-memory-access in dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)
[    4.676149][    T0] Read of size 8 at addr 1fffffff85115558 by task swapper/0/0
[    4.683454][    T0]
[    4.685638][    T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc3-00004-g0e862838f290 #1
[    4.694331][    T0] Hardware name: Supermicro SYS-5018D-FN4T/X10SDV-8C-TLN4F, BIOS 1.1 03/02/2016
[    4.703196][    T0] Call Trace:
[    4.706334][    T0]  <TASK>
[ 4.709133][ T0] ? dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)

after converting the type of the first argument (@nr, bit number)
of arch_test_bit() from `long` to `unsigned long`[0].

Under certain conditions (for example, when ACPI NUMA is disabled
via command line), pxm_to_node() can return %NUMA_NO_NODE (-1).
It is valid 'magic' number of NUMA node, but not valid bit number
to use in bitops.
node_online() eventually descends to test_bit() without checking
for the input, assuming it's on caller side (which might be good
for perf-critical tasks). There, -1 becomes %ULONG_MAX which leads
to an insane array index when calculating bit position in memory.

For now, add an explicit check for @node being not %NUMA_NO_NODE
before calling test_bit(). The actual logics didn't change here
at all.

[0] https://github.com/norov/linux/commit/d59311fead6d25ca4499fb6b2333f71d93bbc19d

Fixes: 576524892222 ("dmar: support for parsing Remapping Hardware Static Affinity structure")
Cc: stable@vger.kernel.org # 2.6.33+
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/iommu/dmar.c