From 9862ec7ac1cbc6eb5ee4a045b5d5b8edbb2f7e68 Mon Sep 17 00:00:00 2001
From: Osama Muhammad <osmtendev@gmail.com>
Date: Wed, 11 Oct 2023 23:46:37 +0500
Subject: [PATCH] FS:JFS:UBSAN:array-index-out-of-bounds in dbAdjTree
Git-commit: 9862ec7ac1cbc6eb5ee4a045b5d5b8edbb2f7e68
Patch-mainline: v6.8-rc1
References: git-fixes CVE-2023-52604 bsc#1221067
Syzkaller reported the following issue:
Ubsan: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2867:6
index 196694 is out of range for type 's8[1365]' (aka 'signed char[1365]')
Cpu: 1 PID: 109 Comm: jfsCommit Not tainted 6.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
dbAdjTree+0x474/0x4f0 fs/jfs/jfs_dmap.c:2867
dbJoin+0x210/0x2d0 fs/jfs/jfs_dmap.c:2834
dbFreeBits+0x4eb/0xda0 fs/jfs/jfs_dmap.c:2331
dbFreeDmap fs/jfs/jfs_dmap.c:2080 [inline]
dbFree+0x343/0x650 fs/jfs/jfs_dmap.c:402
txFreeMap+0x798/0xd50 fs/jfs/jfs_txnmgr.c:2534
txUpdateMap+0x342/0x9e0
txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline]
jfs_lazycommit+0x47a/0xb70 fs/jfs/jfs_txnmgr.c:2732
kthread+0x2d3/0x370 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
</TASK>
================================================================================
Kernel panic - not syncing: UBSAN: panic_on_warn set ...
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
panic+0x30f/0x770 kernel/panic.c:340
check_panic_on_warn+0x82/0xa0 kernel/panic.c:236
ubsan_epilogue lib/ubsan.c:223 [inline]
__ubsan_handle_out_of_bounds+0x13c/0x150 lib/ubsan.c:348
dbAdjTree+0x474/0x4f0 fs/jfs/jfs_dmap.c:2867
dbJoin+0x210/0x2d0 fs/jfs/jfs_dmap.c:2834
dbFreeBits+0x4eb/0xda0 fs/jfs/jfs_dmap.c:2331
dbFreeDmap fs/jfs/jfs_dmap.c:2080 [inline]
dbFree+0x343/0x650 fs/jfs/jfs_dmap.c:402
txFreeMap+0x798/0xd50 fs/jfs/jfs_txnmgr.c:2534
txUpdateMap+0x342/0x9e0
txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline]
jfs_lazycommit+0x47a/0xb70 fs/jfs/jfs_txnmgr.c:2732
kthread+0x2d3/0x370 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
</TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..
The issue is caused when the value of lp becomes greater than
CTLTREESIZE which is the max size of stree. Adding a simple check
solves this issue.
Dave:
As the function returns a void, good error handling
would require a more intrusive code reorganization, so I modified
Osama's patch at use WARN_ON_ONCE for lack of a cleaner option.
The patch is tested via syzbot.
Reported-by: syzbot+39ba34a099ac2e9bd3cb@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=39ba34a099ac2e9bd3cb
Signed-off-by: Osama Muhammad <osmtendev@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Anthony Iliopoulos <ailiop@suse.com>
---
fs/jfs/jfs_dmap.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 11c77757ead9..d55f0dd8d754 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2871,6 +2871,9 @@ static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
/* is the current value the same as the old value ? if so,
* there is nothing to do.
*/
+ if (WARN_ON_ONCE(lp >= CTLTREESIZE))
+ return;
+
if (tp->dmt_stree[lp] == newval)
return;
--
2.43.0