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authorTakashi Iwai <tiwai@suse.de>2021-06-08 17:04:37 +0300
committerTakashi Iwai <tiwai@suse.de>2021-06-09 18:29:38 +0300
commitc305366a37441c2ac90b08711cb6f032b43672f2 (patch)
treec3659325a67ddcb1b7a61939dcb56f511148d698 /sound/isa/sb
parent36e7b12b219dc30a4db046756d81745bc9d69167 (diff)
downloadlinux-c305366a37441c2ac90b08711cb6f032b43672f2.tar.xz
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/sb')
-rw-r--r--sound/isa/sb/sb16_csp.c8
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 */