]> git.baikalelectronics.ru Git - kernel.git/commit
net/xfrm/xfrm_replay: avoid division by zero
authorNickolai Zeldovich <nickolai@csail.mit.edu>
Thu, 17 Jan 2013 18:58:28 +0000 (13:58 -0500)
committerSteffen Klassert <steffen.klassert@secunet.com>
Fri, 18 Jan 2013 05:19:49 +0000 (06:19 +0100)
commitd65b91be1edff5bc6cfded057bf70270048c1281
tree973e37521d6c65eaba2313950ca22b7ca8bee0c4
parent1ab29db7244836f53f17d9e6534b60fb45f89d9f
net/xfrm/xfrm_replay: avoid division by zero

All of the xfrm_replay->advance functions in xfrm_replay.c check if
x->replay_esn->replay_window is zero (and return if so).  However,
one of them, xfrm_replay_advance_bmp(), divides by that value (in the
'%' operator) before doing the check, which can potentially trigger
a divide-by-zero exception.  Some compilers will also assume that the
earlier division means the value cannot be zero later, and thus will
eliminate the subsequent zero check as dead code.

This patch moves the division to after the check.

Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
net/xfrm/xfrm_replay.c