This is a note to let you know that I've just added the patch titled
sound: Prevent buffer overflow in OSS load_mixer_volumes
to the 2.6.36-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sound-prevent-buffer-overflow-in-oss-load_mixer_volumes.patch
and it can be found in the queue-2.6.36 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From d81a12bc29ae4038770e05dce4ab7f26fd5880fb Mon Sep 17 00:00:00 2001
From: Dan Rosenberg <[email protected]>
Date: Sat, 25 Dec 2010 16:23:40 -0500
Subject: sound: Prevent buffer overflow in OSS load_mixer_volumes
From: Dan Rosenberg <[email protected]>
commit d81a12bc29ae4038770e05dce4ab7f26fd5880fb upstream.
The load_mixer_volumes() function, which can be triggered by
unprivileged users via the SOUND_MIXER_SETLEVELS ioctl, is vulnerable to
a buffer overflow. Because the provided "name" argument isn't
guaranteed to be NULL terminated at the expected 32 bytes, it's possible
to overflow past the end of the last element in the mixer_vols array.
Further exploitation can result in an arbitrary kernel write (via
subsequent calls to load_mixer_volumes()) leading to privilege
escalation, or arbitrary kernel reads via get_mixer_levels(). In
addition, the strcmp() may leak bytes beyond the mixer_vols array.
Signed-off-by: Dan Rosenberg <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
sound/oss/soundcard.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/sound/oss/soundcard.c
+++ b/sound/oss/soundcard.c
@@ -86,7 +86,7 @@ int *load_mixer_volumes(char *name, int
int i, n;
for (i = 0; i < num_mixer_volumes; i++) {
- if (strcmp(name, mixer_vols[i].name) == 0) {
+ if (strncmp(name, mixer_vols[i].name, 32) == 0) {
if (present)
mixer_vols[i].num = i;
return mixer_vols[i].levels;
@@ -98,7 +98,7 @@ int *load_mixer_volumes(char *name, int
}
n = num_mixer_volumes++;
- strcpy(mixer_vols[n].name, name);
+ strncpy(mixer_vols[n].name, name, 32);
if (present)
mixer_vols[n].num = n;
Patches currently in stable-queue which might be from [email protected]
are
queue-2.6.36/sound-prevent-buffer-overflow-in-oss-load_mixer_volumes.patch
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