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

From: Quentin Casasnovas
Date: Tue Mar 03 2015 - 10:34:41 EST


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

diff --git fs/btrfs/tree-log.c fs/btrfs/tree-log.c
index 9a37f8b..c5b8ba3 100644
--- fs/btrfs/tree-log.c
+++ fs/btrfs/tree-log.c
@@ -1012,7 +1012,7 @@ 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);

--
2.0.5

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