Messages in this thread | | | Date | Sun, 21 Dec 2008 15:46:39 +0100 | From | "Vegard Nossum" <> | Subject | Re: [PATCH] netlink: fix (theoretical) overrun in message iteration |
| |
On Sun, Dec 21, 2008 at 3:44 PM, Vegard Nossum <vegard.nossum@gmail.com> wrote: > On Sun, Dec 21, 2008 at 2:42 PM, Vegard Nossum <vegard.nossum@gmail.com> wrote: >> From bb805d89e84ddb11c9bb58afcfd9a6b37bbe5a9b Mon Sep 17 00:00:00 2001 >> From: Vegard Nossum <vegard.nossum@gmail.com> >> Date: Sun, 21 Dec 2008 14:20:49 +0100 >> Subject: [PATCH] netlink: fix (theoretical) overrun in message iteration >> >> See commit 1045b03e07d85f3545118510a587035536030c1c for a detailed >> explanation of why this patch is necessary. >> >> In short, nlmsg_next() can make "remaining" go negative, and the >> remaining >= sizeof(...) comparison will promote "remaining" to an >> unsigned type, which means that the expression will evaluate to >> true for negative numbers, even though it was not intended. >> >> I put "theoretical" in the title because I have no evidence that >> this can actually happen, but I suspect that a crafted netlink >> packet can trigger some badness. > > nlmsg
Oops. I meant to say that nlmsg_for_each_msg() has no users at all, which means that the change is all the more "theoretical" :-)
Vegard
-- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036
| |