apparmor: fix off-by-one comparison on MAXMAPPED_SIG
authorJohn Johansen <john.johansen@canonical.com>
Wed, 8 Nov 2017 16:09:52 +0000 (08:09 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 8 Nov 2017 18:56:22 +0000 (10:56 -0800)
commitf7dc4c9a855a13dbb33294c9fc94f17af03f6291
tree9ce322841e592dae220139d91d5e48e555987a70
parentfbc3edf7d7731d7a22c483c679700589bab936a3
apparmor: fix off-by-one comparison on MAXMAPPED_SIG

This came in yesterday, and I have verified our regression tests
were missing this and it can cause an oops. Please apply.

There is a an off-by-one comparision on sig against MAXMAPPED_SIG
that can lead to a read outside the sig_map array if sig
is MAXMAPPED_SIG. Fix this.

Verified that the check is an out of bounds case that can cause an oops.

Revised: add comparison fix to second case
Fixes: cd1dbf76b23d ("apparmor: add the ability to mediate signals")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
security/apparmor/ipc.c