On 06/25/2015 09:06 AM, David Sterba wrote:
On Thu, Jun 18, 2015 at 10:16:54AM -0700, Josef Bacik wrote:
On 06/18/2015 09:44 AM, David Sterba wrote:
On Thu, Jun 18, 2015 at 01:59:13AM +0200, Robert Marklund wrote:
This could crash before because of dangerous dangling
offset of pointer.
That's right, this can happen. There are more btrfs_item_ptr that would
be good to validate that way, namely in the checker as it's most likely
to see corrupted data.
The check_block stuff should be doing this, if it isn't that's where we
need to fix it. Thanks,
Something like that?
--- a/ctree.c
+++ b/ctree.c
@@ -521,6 +521,19 @@ btrfs_check_leaf(struct btrfs_root *root, struct
btrfs_disk_key *parent_key,
goto fail;
}
}
+
+ for (i = 0; i < nritems; i++) {
+ void *tmp;
+
+ tmp = btrfs_item_ptr(buf, i, void);
+ if ((long)tmp >= BTRFS_LEAF_DATA_SIZE(root)) {
+ ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS;
+ fprintf(stderr, "bad item pointer %lu\n",
+ (long)tmp);
+ goto fail;
+ }
+ }
I'd just do
if (btrfs_item_end_nr(buf, i) >= BTRFS_LEAF_DATA_SIZE(root))
that way you catch problems with offset and size. Thanks,
Josef
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