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| author |   Takashi Iwai <tiwai@suse.de> | 2021-06-08 16:04:37 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-06-09 17:29:38 +0200 |
| commit | c305366a37441c2ac90b08711cb6f032b43672f2 (patch) | |
| tree | c3659325a67ddcb1b7a61939dcb56f511148d698 /sound/isa | |
| parent | ALSA: sb: Minor coding style fixes (diff) | |
| download | linux-dev-c305366a37441c2ac90b08711cb6f032b43672f2.tar.xz linux-dev-c305366a37441c2ac90b08711cb6f032b43672f2.zip | |
ALSA: sb: Fix potential double-free of CSP mixer elements
snd_sb_qsound_destroy() contains the calls of removing the previously
created mixer controls, but it doesn't clear the pointers. As
snd_sb_qsound_destroy() itself may be repeatedly called via ioctl,
this could lead to double-free potentially.
Fix it by clearing the struct fields properly afterwards.
Link: https://lore.kernel.org/r/20210608140540.17885-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/isa')
| -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 dec68ae6b599..5bbe6695689d 100644 --- a/sound/isa/sb/sb16_csp.c +++ b/sound/isa/sb/sb16_csp.c @@ -1077,10 +1077,14 @@ static void snd_sb_qsound_destroy(struct snd_sb_csp * p) card = p->chip->card; down_write(&card->controls_rwsem); - if (p->qsound_switch) + if (p->qsound_switch) { snd_ctl_remove(card, p->qsound_switch); - if (p->qsound_space) + p->qsound_switch = NULL; + } + if (p->qsound_space) { snd_ctl_remove(card, p->qsound_space); + p->qsound_space = NULL; + } up_write(&card->controls_rwsem); /* cancel pending transfer of QSound parameters */ |