From 17e6afc75ad0150d265a86a8f155b2871f9c07fe Mon Sep 17 00:00:00 2001
From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Date: Tue, 9 Jan 2007 08:57:34 -0600
Subject: JFS: Avoid BUG() on a damaged file system
On Mon, 2006-12-18 at 19:51 +0100, Eric Sesterhenn wrote:
> hi,
>
> while playing around with fsfuzzer, i got the following oops with jfs:
>
> [ 851.804875] BUG at fs/jfs/jfs_xtree.c:760
> assert(!BT_STACK_FULL(btstack))
> [ 851.805179] ------------[ cut here ]------------
> [ 851.805238] kernel BUG at fs/jfs/jfs_xtree.c:760!
JFS should mark the superblock dirty and return an error rather than
calling BUG().
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
---
fs/jfs/jfs_xtree.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
(limited to 'fs')
diff --git a/fs/jfs/jfs_xtree.c b/fs/jfs/jfs_xtree.c
index e98eb03e53..acc97c46d8 100644
--- a/fs/jfs/jfs_xtree.c
+++ b/fs/jfs/jfs_xtree.c
@@ -757,6 +757,11 @@ static int xtSearch(struct inode *ip, s64 xoff, s64 *nextp,
nsplit = 0;
/* push (bn, index) of the parent page/entry */
+ if (BT_STACK_FULL(btstack)) {
+ jfs_error(ip->i_sb, "stack overrun in xtSearch!");
+ XT_PUTPAGE(mp);
+ return -EIO;
+ }
BT_PUSH(btstack, bn, index);
/* get the child page block number */
@@ -3915,6 +3920,11 @@ s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int flag)
*/
getChild:
/* save current parent entry for the child page */
+ if (BT_STACK_FULL(&btstack)) {
+ jfs_error(ip->i_sb, "stack overrun in xtTruncate!");
+ XT_PUTPAGE(mp);
+ return -EIO;
+ }
BT_PUSH(&btstack, bn, index);
/* get child page */
@@ -4112,6 +4122,11 @@ s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size)
*/
getChild:
/* save current parent entry for the child page */
+ if (BT_STACK_FULL(&btstack)) {
+ jfs_error(ip->i_sb, "stack overrun in xtTruncate_pmap!");
+ XT_PUTPAGE(mp);
+ return -EIO;
+ }
BT_PUSH(&btstack, bn, index);
/* get child page */
--
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