On Sat, Feb 03, 2018 at 08:33:27PM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebigg...@google.com>
>
> syzkaller hit a WARN() in ata_qc_issue() when writing to /dev/sg0. This
> happened because it issued a READ_6 command with no data buffer.
>
> Just remove the WARN(), as it doesn't appear indicate a kernel bug. The
> expected behavior is to fail the command, which the code does.
>
> Here's a reproducer that works in QEMU when /dev/sg0 refers to a disk of
> the default type ("82371SB PIIX3 IDE"):
>
> #include <fcntl.h>
> #include <unistd.h>
>
> int main()
> {
> char buf[42] = { [36] = 0x8 /* READ_6 */ };
>
> write(open("/dev/sg0", O_RDWR), buf, sizeof(buf));
> }
>
> Fixes: f92a26365a72 ("libata: change ATA_QCFLAG_DMAMAP semantics")
> Reported-by:
> syzbot+f7b556d1766502a69d85071d2ff08bd87be53...@syzkaller.appspotmail.com
> Cc: <sta...@vger.kernel.org> # v2.6.25+
> Signed-off-by: Eric Biggers <ebigg...@google.com>
Applied to libata/for-4.16-fixes.
Thanks.
--
tejun
