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authorMike Snitzer <snitzer@redhat.com>2017-01-25 16:24:52 +0100
committerMike Snitzer <snitzer@redhat.com>2017-02-03 16:18:43 +0100
commit4087a1fffe38106e10646606a27f10d40451862d (patch)
treebba4836d57a0ff1922c1831c62ba22b6bfd43794 /drivers/md
parentdm mpath: cleanup -Wbool-operation warning in choose_pgpath() (diff)
downloadlinux-4087a1fffe38106e10646606a27f10d40451862d.tar.xz
linux-4087a1fffe38106e10646606a27f10d40451862d.zip
dm rq: cope with DM device destruction while in dm_old_request_fn()
Fixes a crash in dm_table_find_target() due to a NULL struct dm_table being passed from dm_old_request_fn() that races with DM device destruction. Reported-by: artem@flashgrid.io Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-rq.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 9d7275fb541a..6e702fc69a83 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -779,6 +779,10 @@ static void dm_old_request_fn(struct request_queue *q)
int srcu_idx;
struct dm_table *map = dm_get_live_table(md, &srcu_idx);
+ if (unlikely(!map)) {
+ dm_put_live_table(md, srcu_idx);
+ return;
+ }
ti = dm_table_find_target(map, pos);
dm_put_live_table(md, srcu_idx);
}