2.6.32-longterm review patch. If anyone has any objections, please let us know.
------------------ 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 @@ -87,7 +87,7 @@ 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; @@ -99,7 +99,7 @@ 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; _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
