From: NeilBrown Date: Fri, 14 Aug 2015 07:04:21 +0000 (+1000) Subject: md/bitmap: return an error when bitmap superblock is corrupt. X-Git-Tag: firefly_0821_release~3679^2~164 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bc0a524cd874cb33146b641c4c8152a22b7da070;p=firefly-linux-kernel-4.4.55.git md/bitmap: return an error when bitmap superblock is corrupt. commit b97e92574c0bf335db1cd2ec491d8ff5cd5d0b49 upstream Use separate bitmaps for each nodes in the cluster bitmap_read_sb() validates the bitmap superblock that it reads in. If it finds an inconsistency like a bad magic number or out-of-range version number, it prints an error and returns, but it incorrectly returns zero, so the array is still assembled with the (invalid) bitmap. This means it could try to use a bitmap with a new version number which it therefore does not understand. This bug was introduced in 3.5 and fix as part of a larger patch in 4.1. So the patch is suitable for any -stable kernel in that range. Fixes: 27581e5ae01f ("md/bitmap: centralise allocation of bitmap file pages.") Signed-off-by: NeilBrown Reported-by: GuoQing Jiang --- diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index a79cbd6038f6..37470ee7c850 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -564,6 +564,8 @@ static int bitmap_read_sb(struct bitmap *bitmap) if (err) return err; + err = -EINVAL; + sb = kmap_atomic(sb_page); chunksize = le32_to_cpu(sb->chunksize);