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| author | Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-04-26 07:55:41 -0700 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-04-26 18:01:07 +0200 |
| commit | 4fb44dd2c1dda18606348acdfdb97e8759dde9df (patch) | |
| tree | 4df776bf00dc1d1d50a1214ad5ab0562009ccb3f | |
| parent | 0301201b7181a927b59421097a01ee98683aa67c (diff) | |
| download | linux-4fb44dd2c1dda18606348acdfdb97e8759dde9df.tar.gz | |
ALSA: sb: Fix two use after free in snd_sb_qsound_build
In snd_sb_qsound_build, snd_ctl_add(..,p->qsound_switch...) and snd_ctl_add(..,p->qsound_space..) are called. But the second arguments of snd_ctl_add() could be freed via snd_ctl_add_replace() ->snd_ctl_free_one(). After the error code is returned, snd_sb_qsound_destroy(p) is called in __error branch. But in snd_sb_qsound_destroy(), the freed p->qsound_switch and p->qsound_space are still used by snd_ctl_remove(). My patch set p->qsound_switch and p->qsound_space to NULL if snd_ctl_add() failed to avoid the uaf bugs. But these codes need to further be improved with the code style. Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210426145541.8070-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/isa/sb/sb16_csp.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/sound/isa/sb/sb16_csp.c b/sound/isa/sb/sb16_csp.c index 8635a2b6b36b..4789345a8fdd 100644 --- a/sound/isa/sb/sb16_csp.c +++ b/sound/isa/sb/sb16_csp.c @@ -1045,10 +1045,14 @@ static int snd_sb_qsound_build(struct snd_sb_csp * p) spin_lock_init(&p->q_lock); - if ((err = snd_ctl_add(card, p->qsound_switch = snd_ctl_new1(&snd_sb_qsound_switch, p))) < 0) + if ((err = snd_ctl_add(card, p->qsound_switch = snd_ctl_new1(&snd_sb_qsound_switch, p))) < 0) { + p->qsound_switch = NULL; goto __error; - if ((err = snd_ctl_add(card, p->qsound_space = snd_ctl_new1(&snd_sb_qsound_space, p))) < 0) + } + if ((err = snd_ctl_add(card, p->qsound_space = snd_ctl_new1(&snd_sb_qsound_space, p))) < 0) { + p->qsound_space = NULL; goto __error; + } return 0; |