Fix firmware loader uevent buffer NULL pointer dereference
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 9 Jul 2015 18:20:01 +0000 (11:20 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 9 Jul 2015 18:20:01 +0000 (11:20 -0700)
commit6f957724b94cb19f5c1c97efd01dd4df8ced323c
treea5f0dc7258865efa5c39e80cf729f7db5d0c970f
parent6b7339f4c31ad69c8e9c0b2859276e22cf72176d
Fix firmware loader uevent buffer NULL pointer dereference

The firmware class uevent function accessed the "fw_priv->buf" buffer
without the proper locking and testing for NULL.  This is an old bug
(looks like it goes back to 2012 and commit 1244691c73b2: "firmware
loader: introduce firmware_buf"), but for some reason it's triggering
only now in 4.2-rc1.

Shuah Khan is trying to bisect what it is that causes this to trigger
more easily, but in the meantime let's just fix the bug since others are
hitting it too (at least Ingo reports having seen it as well).

Reported-and-tested-by: Shuah Khan <shuahkh@osg.samsung.com>
Acked-by: Ming Lei <ming.lei@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/firmware_class.c