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authorYufen Yu <yuyufen@huawei.com>2019-04-02 14:22:14 +0800
committerSong Liu <songliubraving@fb.com>2019-04-10 15:26:08 -0700
commitee37e62191a59d253fc916b9fc763deb777211e2 (patch)
tree09696aa3b9f5d4736149fa19fd8427e80ed858a0 /drivers/md
parent0d413829bd20d5563c2c3287479a7348810cb13f (diff)
downloadlinux-ee37e62191a59d253fc916b9fc763deb777211e2.tar.gz
md: add mddev->pers to avoid potential NULL pointer dereference
When doing re-add, we need to ensure rdev->mddev->pers is not NULL, which can avoid potential NULL pointer derefence in fallowing add_bound_rdev(). Fixes: a6da4ef85cef ("md: re-add a failed disk") Cc: Xiao Ni <xni@redhat.com> Cc: NeilBrown <neilb@suse.com> Cc: <stable@vger.kernel.org> # 4.4+ Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1fa2682951f1..664b77ceaf2d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2850,8 +2850,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
err = 0;
}
} else if (cmd_match(buf, "re-add")) {
- if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
- rdev->saved_raid_disk >= 0) {
+ if (!rdev->mddev->pers)
+ err = -EINVAL;
+ else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
+ rdev->saved_raid_disk >= 0) {
/* clear_bit is performed _after_ all the devices
* have their local Faulty bit cleared. If any writes
* happen in the meantime in the local node, they