From f3ee37d5415d726557eb5d9cf2973c54d735916a Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sat, 29 May 2021 17:27:27 +0200 Subject: [PATCH] 4.4-stable patches added patches: dm-snapshot-properly-fix-a-crash-when-an-origin-has-no-snapshots.patch --- ...rash-when-an-origin-has-no-snapshots.patch | 35 +++++++++++++++++++ queue-4.4/series | 1 + 2 files changed, 36 insertions(+) create mode 100644 queue-4.4/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 index 00000000000..665ab9d6433 --- /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 +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 + +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 +Cc: stable@vger.kernel.org +Signed-off-by: Mike Snitzer +Signed-off-by: Greg Kroah-Hartman +--- + 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 1ed7e925b07..80348362f99 100644 --- 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 -- 2.47.3