From: Takashi Iwai tiwai@suse.de
stable inclusion from stable-5.10.52 commit 0e54f8ee6bff85def622bfa29f74569fb824536a bugzilla: 175542 https://gitee.com/openeuler/kernel/issues/I4DTKU
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit c305366a37441c2ac90b08711cb6f032b43672f2 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- sound/isa/sb/sb16_csp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/sound/isa/sb/sb16_csp.c b/sound/isa/sb/sb16_csp.c index 1528e04a4d28..dbcd9ab2c2b7 100644 --- a/sound/isa/sb/sb16_csp.c +++ b/sound/isa/sb/sb16_csp.c @@ -1072,10 +1072,14 @@ 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 */