freevxfs: possible null pointer dereference fix

sb_read may return NULL, so let's explicitly check it.

Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/fs/freevxfs/vxfs_bmap.c b/fs/freevxfs/vxfs_bmap.c
index 2d71128bd8d6..f86fd3cacd5a 100644
--- a/fs/freevxfs/vxfs_bmap.c
+++ b/fs/freevxfs/vxfs_bmap.c
@@ -137,7 +137,7 @@ vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
 
                 bp = sb_bread(ip->i_sb,
                                 indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
-                if (!buffer_mapped(bp))
+                if (!bp || !buffer_mapped(bp))
                         return 0;
 
                 typ = ((struct vxfs_typed *)bp->b_data) +
diff --git a/fs/freevxfs/vxfs_inode.c b/fs/freevxfs/vxfs_inode.c
index 098a915fd9a1..d1f7c5b5b3c3 100644
--- a/fs/freevxfs/vxfs_inode.c
+++ b/fs/freevxfs/vxfs_inode.c
@@ -99,7 +99,7 @@ vxfs_blkiget(struct super_block *sbp, u_long extent, ino_t ino)
         offset = ((ino % (sbp->s_blocksize / VXFS_ISIZE)) * VXFS_ISIZE);
         bp = sb_bread(sbp, block);
 
-        if (buffer_mapped(bp)) {
+        if (bp && buffer_mapped(bp)) {
                 struct vxfs_inode_info  *vip;
                 struct vxfs_dinode      *dip;