[ 110/110] bcache: Fix a null ptr deref regression

From: Greg Kroah-Hartman
Date: Fri Oct 11 2013 - 16:20:17 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kent Overstreet <kmo@xxxxxxxxxxxxx>

commit 2fe80d3bbf1c8bd9efc5b8154207c8dd104e7306 upstream.

Commit c0f04d88e46d ("bcache: Fix flushes in writeback mode") was fixing
a reported data corruption bug, but it seems some last minute
refactoring or rebasing introduced a null pointer deref.

Signed-off-by: Kent Overstreet <kmo@xxxxxxxxxxxxx>
Reported-by: Gabriel de Perthuis <g2p.code@xxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/md/bcache/request.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1055,6 +1055,7 @@ static void request_write(struct cached_
} else {
trace_bcache_writeback(s->orig_bio);
bch_writeback_add(dc, bio_sectors(bio));
+ s->op.cache_bio = bio;

if (bio->bi_rw & REQ_FLUSH) {
/* Also need to send a flush to the backing device */
@@ -1067,8 +1068,6 @@ static void request_write(struct cached_
flush->bi_private = cl;

closure_bio_submit(flush, cl, s->d);
- } else {
- s->op.cache_bio = bio;
}
}
out:


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