Subject: CVE-2023-52604: FS:JFS:UBSAN:array-index-out-of-bounds in dbAdjTree

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

FS:JFS:UBSAN:array-index-out-of-bounds in dbAdjTree

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 ...
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
 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.

The Linux kernel CVE team has assigned CVE-2023-52604 to this issue.

Affected and fixed versions
===========================

	Fixed in 4.19.307 with commit e3e95c685066
	Fixed in 5.4.269 with commit 98f9537fe61b
	Fixed in 5.10.210 with commit de34de6e57bb
	Fixed in 5.15.149 with commit 6fe8b702125a
	Fixed in 6.1.77 with commit 42f433785f10
	Fixed in 6.6.16 with commit 6a44065dd604
	Fixed in 6.7.4 with commit 59342822276f
	Fixed in 6.8 with commit 9862ec7ac1cb

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-52604
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	fs/jfs/jfs_dmap.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/e3e95c6850661c77e6dab079d9b5374a618ebb15
	https://git.kernel.org/stable/c/98f9537fe61b8382b3cc5dd97347531698517c56
	https://git.kernel.org/stable/c/de34de6e57bbbc868e4fcf9e98c76b3587cabb0b
	https://git.kernel.org/stable/c/6fe8b702125aeee6ce83f20092a2341446704e7b
	https://git.kernel.org/stable/c/42f433785f108893de0dd5260bafb85d7d51db03
	https://git.kernel.org/stable/c/6a44065dd604972ec1fbcccbdc4a70d266a89cdd
	https://git.kernel.org/stable/c/59342822276f753e49d27ef5eebffbba990572b9
	https://git.kernel.org/stable/c/9862ec7ac1cbc6eb5ee4a045b5d5b8edbb2f7e68