On Thu, Dec 21, 2017 at 08:44:32AM -0800, Santosh Shilimkar wrote:

+Avinash

On 12/21/2017 1:10 AM, syzbot wrote:

quoted

syzkaller has found reproducer for the following crash on

[..]

quoted

audit: type=1400 audit(1513847224.110:7): avc:  denied  { map } for
pid=3157 comm="syzkaller455006" path="/root/syzkaller455006870"
dev="sda1" ino=16481
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: stack-out-of-bounds in rds_rdma_bytes net/rds/send.c:1013
[inline]

Could you please post the discussed fix if you are ready with it ?
This new report is same as last one and cmesg length check should
address it.

Regards,
Santosh

This crash seems to have stopped occurring.  I assume it was fixed by commit
14e138a86f63 (thanks Avinash!), so let's tell syzbot so that it can start
reporting crashes in the same place again:

#syz fix: RDS: Check cmsg_len before dereferencing CMSG_DATA

- Eric