4.4-stable patches

added patches:
	dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch

diff --git a/queue-4.4/dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch b/queue-4.4/dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch
new file mode 100644 (file)
index 0000000..665ab9d
--- /dev/null
+++ b/queue-4.4/dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch
@@ -0,0 +1,35 @@
+From 7e768532b2396bcb7fbf6f82384b85c0f1d2f197 Mon Sep 17 00:00:00 2001
+From: Mikulas Patocka <mpatocka@redhat.com>
+Date: Tue, 25 May 2021 13:17:19 -0400
+Subject: dm snapshot: properly fix a crash when an origin has no snapshots
+
+From: Mikulas Patocka <mpatocka@redhat.com>
+
+commit 7e768532b2396bcb7fbf6f82384b85c0f1d2f197 upstream.
+
+If an origin target has no snapshots, o->split_boundary is set to 0.
+This causes BUG_ON(sectors <= 0) in block/bio.c:bio_split().
+
+Fix this by initializing chunk_size, and in turn split_boundary, to
+rounddown_pow_of_two(UINT_MAX) -- the largest power of two that fits
+into "unsigned" type.
+
+Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
+Cc: stable@vger.kernel.org
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/md/dm-snap.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/md/dm-snap.c
++++ b/drivers/md/dm-snap.c
+@@ -789,7 +789,7 @@ static int dm_add_exception(void *contex
+ static uint32_t __minimum_chunk_size(struct origin *o)
+ {
+       struct dm_snapshot *snap;
+-      unsigned chunk_size = 0;
++      unsigned chunk_size = rounddown_pow_of_two(UINT_MAX);
+ 
+       if (o)
+               list_for_each_entry(snap, &o->snapshots, list)

diff --git a/queue-4.4/series b/queue-4.4/series
index 1ed7e925b07fe3a22153f35ad4485ffec21f807e..80348362f9971173b529e54f46388d9242e9cf82 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -5,3 +5,4 @@ proc-check-proc-pid-attr-writes-against-file-opener.patch
 net-hso-fix-control-request-directions.patch
 mac80211-assure-all-fragments-are-encrypted.patch
 mac80211-prevent-mixed-key-and-fragment-cache-attacks.patch
+dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch