diff options
| author | Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-04-26 16:11:29 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-04-26 17:23:41 +0300 |
| commit | 1c98f574403dbcf2eb832d5535a10d967333ef2d (patch) | |
| tree | 554d0fa0bd9914a852e5289120a93c8f49307720 /sound | |
| parent | 9bbb94e57df135ef61bef075d9c99b8d9e89e246 (diff) | |
| download | linux-1c98f574403dbcf2eb832d5535a10d967333ef2d.tar.xz | |
ALSA: emu8000: Fix a use after free in snd_emu8000_create_mixer
Our code analyzer reported a uaf.
In snd_emu8000_create_mixer, the callee snd_ctl_add(..,emu->controls[i])
calls snd_ctl_add_replace(.., kcontrol,..). Inside snd_ctl_add_replace(),
if error happens, kcontrol will be freed by snd_ctl_free_one(kcontrol).
Then emu->controls[i] points to a freed memory, and the execution comes
to __error branch of snd_emu8000_create_mixer. The freed emu->controls[i]
is used in snd_ctl_remove(card, emu->controls[i]).
My patch set emu->controls[i] to NULL if snd_ctl_add() failed to avoid
the uaf.
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210426131129.4796-1-lyl2019@mail.ustc.edu.cn
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/isa/sb/emu8000.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/isa/sb/emu8000.c b/sound/isa/sb/emu8000.c index 0aa545ac6e60..1c90421a88dc 100644 --- a/sound/isa/sb/emu8000.c +++ b/sound/isa/sb/emu8000.c @@ -1029,8 +1029,10 @@ snd_emu8000_create_mixer(struct snd_card *card, struct snd_emu8000 *emu) memset(emu->controls, 0, sizeof(emu->controls)); for (i = 0; i < EMU8000_NUM_CONTROLS; i++) { - if ((err = snd_ctl_add(card, emu->controls[i] = snd_ctl_new1(mixer_defs[i], emu))) < 0) + if ((err = snd_ctl_add(card, emu->controls[i] = snd_ctl_new1(mixer_defs[i], emu))) < 0) { + emu->controls[i] = NULL; goto __error; + } } return 0; |