md: Avoid write invalid address if read_seqretry returned true.

If read_seqretry returned true and bbp was changed, it will write
invalid address which can cause some serious problem.

This bug was introduced by commit v3.0-rc7-130-g2699b67.
So fix is suitable for 3.0.y thru 3.6.y.

Reported-by: zhuwenfeng@kedacom.com
Tested-by: zhuwenfeng@kedacom.com
Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
majianpeng 2012-11-08 08:56:27 +08:00 committed by NeilBrown
parent ab05613a06
commit 35f9ac2dce

View File

@ -1817,10 +1817,10 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
memset(bbp, 0xff, PAGE_SIZE);
for (i = 0 ; i < bb->count ; i++) {
u64 internal_bb = *p++;
u64 internal_bb = p[i];
u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
| BB_LEN(internal_bb));
*bbp++ = cpu_to_le64(store_bb);
bbp[i] = cpu_to_le64(store_bb);
}
bb->changed = 0;
if (read_seqretry(&bb->lock, seq))