[PATCH] md/raid5: fix possible NULL pointer dereference in debug routine
STALE5578d
From: Namhyung Kim <hidden>
Date: 2011-06-24 05:04:12
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
When I ran dynamic debug, I encountered a NULL pointer dereference bug in add_stripe_bio(). Prior to second call to pr_debug(), @bi was reused in order to check whether the request is partial write or not, and it could lead to set @bi to NULL. Since we save original @bi pointer into local variable 'bip', use it instead of NULL-able @bi. Also changed confusing 'bh' to 'bi' in the first message. Signed-off-by: Namhyung Kim <redacted> --- drivers/md/raid5.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 82c07fb38961..c814a6075c79 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c@@ -2139,7 +2139,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in raid5_conf_t *conf = sh->raid_conf; int firstwrite=0; - pr_debug("adding bh b#%llu to stripe s#%llu\n", + pr_debug("adding bi b#%llu to stripe s#%llu\n", (unsigned long long)bi->bi_sector, (unsigned long long)sh->sector);
@@ -2181,7 +2181,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in spin_unlock_irq(&conf->device_lock); pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n", - (unsigned long long)bi->bi_sector, + (unsigned long long)(*bip)->bi_sector, (unsigned long long)sh->sector, dd_idx); if (conf->mddev->bitmap && firstwrite) {
--
1.7.5.2