]> git.baikalelectronics.ru Git - kernel.git/commit
drbd: Fix five use after free bugs in get_initial_state
authorLv Yunlong <lyl2019@mail.ustc.edu.cn>
Wed, 6 Apr 2022 19:04:43 +0000 (21:04 +0200)
committerJens Axboe <axboe@kernel.dk>
Wed, 6 Apr 2022 19:07:50 +0000 (13:07 -0600)
commitaadb22ba2f656581b2f733deb3a467c48cc618f6
tree0da6e2d5e77b2b3dc9e714cceb8a35ff27686c54
parent4ded53ea0c7d46fa043efc7320e17ca443a1debb
drbd: Fix five use after free bugs in get_initial_state

In get_initial_state, it calls notify_initial_state_done(skb,..) if
cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(),
the skb will be freed by nlmsg_free(skb).
Then get_initial_state will goto out and the freed skb will be used by
return value skb->len, which is a uaf bug.

What's worse, the same problem goes even further: skb can also be
freed in the notify_*_state_change -> notify_*_state calls below.
Thus 4 additional uaf bugs happened.

My patch lets the problem callee functions: notify_initial_state_done
and notify_*_state_change return an error code if errors happen.
So that the error codes could be propagated and the uaf bugs can be avoid.

v2 reports a compilation warning. This v3 fixed this warning and built
successfully in my local environment with no additional warnings.
v2: https://lore.kernel.org/patchwork/patch/1435218/

Fixes: a29728463b254 ("drbd: Backport the "events2" command")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block/drbd/drbd_int.h
drivers/block/drbd/drbd_nl.c
drivers/block/drbd/drbd_state.c
drivers/block/drbd/drbd_state_change.h