[2.6.20.17 review 24/58] md: raid10: fix use-after-free of bio

[Willy Tarreau]

In case of read errors raid10d tries to print a nice error message,
unfortunately using data from an already put bio.

Signed-off-by: Maik Hampel <m.hampel@xxxxxx>
Acked-By: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 drivers/md/raid10.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index fb5d9c6..e0029ea 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1565,7 +1565,6 @@ static void raid10d(mddev_t *mddev)
 			bio = r10_bio->devs[r10_bio->read_slot].bio;
 			r10_bio->devs[r10_bio->read_slot].bio =
 				mddev->ro ? IO_BLOCKED : NULL;
-			bio_put(bio);
 			mirror = read_balance(conf, r10_bio);
 			if (mirror == -1) {
 				printk(KERN_ALERT "raid10: %s: unrecoverable I/O"
@@ -1573,8 +1572,10 @@ static void raid10d(mddev_t *mddev)
 				       bdevname(bio->bi_bdev,b),
 				       (unsigned long long)r10_bio->sector);
 				raid_end_bio_io(r10_bio);
+				bio_put(bio);
 			} else {
 				const int do_sync = bio_sync(r10_bio->master_bio);
+				bio_put(bio);
 				rdev = conf->mirrors[mirror].rdev;
 				if (printk_ratelimit())
 					printk(KERN_ERR "raid10: %s: redirecting sector %llu to"
-- 
1.5.2.5

-- 
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