[PATCH 3.19 074/177] Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.

Greg Kroah-Hartman
2015-03-16T14:14:12Z

From: Quentin Casasnovas <quentin.casasnovas@oracle.com>

commit dd9ef135e3542ffc621c4eb7f0091870ec7a1504 upstream.

Improper arithmetics when calculting the address of the extended ref could
lead to an out of bounds memory read and kernel panic.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/tree-log.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1010,7 +1010,7 @@ again:
base = btrfs_item_ptr_offset(leaf, path->slots[0]);

while (cur_offset < item_size) {
- extref = (struct btrfs_inode_extref *)base + cur_offset;
+ extref = (struct btrfs_inode_extref *)(base + cur_offset);

victim_name_len = btrfs_inode_extref_name_len(leaf, extref);