From: "Fabio M. De Francesco" fmdefrancesco@gmail.com
stable inclusion from stable-v5.10.112 commit 912797e54c99a98f0722f21313e13a3938bb6dba category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5HL0X
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 2f7a26abb8241a0208c68d22815aa247c5ddacab upstream.
Syzbot reports "KASAN: null-ptr-deref Write in snd_pcm_format_set_silence".[1]
It is due to missing validation of the "silence" field of struct "pcm_format_data" in "pcm_formats" array.
Add a test for valid "pat" and, if it is not so, return -EINVAL.
[1] https://lore.kernel.org/lkml/000000000000d188ef05dc2c7279@google.com/
Reported-and-tested-by: syzbot+205eb15961852c2c5974@syzkaller.appspotmail.com Signed-off-by: Fabio M. De Francesco fmdefrancesco@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220409012655.9399-1-fmdefrancesco@gmail.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- sound/core/pcm_misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index 257d412eac5d..30f0f96e0000 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -429,7 +429,7 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int return 0; width = pcm_formats[(INT)format].phys; /* physical width */ pat = pcm_formats[(INT)format].silence; - if (! width) + if (!width || !pat) return -EINVAL; /* signed or 1 byte data */ if (pcm_formats[(INT)format].signd == 1 || width <= 8) {