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| author | Mikulas Patocka <mpatocka@redhat.com> | 2021-05-25 13:17:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-03 08:59:02 +0200 |
| commit | d65ec240b3e43e8637dac93dcd8d9134646d608c (patch) | |
| tree | c4aec151c104a420decbdcd1239e5109c2830af7 /drivers/md/dm-snap.c | |
| parent | b06fe1124369b394de89e934478eefec8d5a3f1d (diff) | |
| download | linux-stable-d65ec240b3e43e8637dac93dcd8d9134646d608c.tar.gz linux-stable-d65ec240b3e43e8637dac93dcd8d9134646d608c.tar.bz2 linux-stable-d65ec240b3e43e8637dac93dcd8d9134646d608c.zip | |
dm snapshot: properly fix a crash when an origin has no snapshots
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>
Diffstat (limited to 'drivers/md/dm-snap.c')
| -rw-r--r-- | drivers/md/dm-snap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index add7d4ce4180..e902aae685af 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -854,7 +854,7 @@ static int dm_add_exception(void *context, chunk_t old, chunk_t new) 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) |