cd47a2ccc6
commit 9173e5e80729c8434b8d27531527c5245f4a5594 upstream.
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+f7b556d1766502a69d85071d2ff08bd87be53d0f@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org> # v2.6.25+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.