From: Kent Overstreet <kmo@daterainc.com>
Date: Fri, 11 Oct 2013 00:31:15 +0000 (-0700)
Subject: bcache: Fix a null ptr deref regression
X-Git-Tag: firefly_0821_release~176^2~5167
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2fe80d3bbf1c8bd9efc5b8154207c8dd104e7306;p=firefly-linux-kernel-4.4.55.git

bcache: Fix a null ptr deref regression

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@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Reported-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 71eb233b9ace..b6a74bcbb08f 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -996,6 +996,7 @@ static void request_write(struct cached_dev *dc, struct search *s)
 		closure_bio_submit(bio, cl, s->d);
 	} else {
 		bch_writeback_add(dc);
+		s->op.cache_bio = bio;
 
 		if (bio->bi_rw & REQ_FLUSH) {
 			/* Also need to send a flush to the backing device */
@@ -1008,8 +1009,6 @@ static void request_write(struct cached_dev *dc, struct search *s)
 			flush->bi_private = cl;
 
 			closure_bio_submit(flush, cl, s->d);
-		} else {
-			s->op.cache_bio = bio;
 		}
 	}
 out: