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=... -------------------------------- 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) { -- 2.20.1