linux-stable/arch/mips/include
James Hogan 2f9eed6e37 MIPS: Drop spurious __unused in struct compat_flock
commit 6ae1756fad upstream.

MIPS' struct compat_flock doesn't match the 32-bit struct flock, as it
has an extra short __unused before pad[4], which combined with alignment
increases the size to 40 bytes compared with struct flock's 36 bytes.

Since commit 8c6657cb50 ("Switch flock copyin/copyout primitives to
copy_{from,to}_user()"), put_compat_flock() writes the full compat_flock
struct to userland, which results in corruption of the userland word
after the struct flock when running 32-bit userlands on 64-bit kernels.

This was observed to cause a bus error exception when starting Firefox
on Debian 8 (Jessie).

Reported-by: Peter Mamonov <pmamonov@gmail.com>
Signed-off-by: James Hogan <jhogan@kernel.org>
Tested-by: Peter Mamonov <pmamonov@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.13+
Patchwork: https://patchwork.linux-mips.org/patch/18646/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 10:19:38 +01:00
..
asm MIPS: Drop spurious __unused in struct compat_flock 2018-02-28 10:19:38 +01:00
uapi/asm License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00