hfsplus: Add additional range check to handle on-disk corruptions

'recoff' is read from disk and used for an argument to memcpy, so if the value read from disk is larger than the page size, it result to "general protection fault". This patch add additional range check for the value, so that disk fuzz won't cause such fault. Signed-off-by: Naohiro Aota <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]>
chewitt · Jul 22, 2011 · aac4e41 · aac4e41
1 parent dd7f3d5
commit aac4e41
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c
@@ -43,6 +43,10 @@ u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
 			node->tree->node_size - (rec + 1) * 2);
 		if (!recoff)
 			return 0;
+		if (recoff > node->tree->node_size - 2) {
+			printk(KERN_ERR "hfs: recoff %d too large\n", recoff);
+			return 0;
+		}
 
 		retval = hfs_bnode_read_u16(node, recoff) + 2;
 		if (retval > node->tree->max_key_len + 2) {