Lucene search

K
vulnrichmentLinuxVULNRICHMENT:CVE-2024-40952
HistoryJul 12, 2024 - 12:31 p.m.

CVE-2024-40952 ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty()

2024-07-1212:31:56
Linux
github.com
3
linux kernel ocfs2 vulnerability

AI Score

6.7

Confidence

Low

SSVC

Exploitation

none

Automatable

no

Technical Impact

partial

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

ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty()

bdev->bd_super has been removed and commit 8887b94d9322 change the usage
from bdev->bd_super to b_assoc_map->host->i_sb. This introduces the
following NULL pointer dereference in ocfs2_journal_dirty() since
b_assoc_map is still not initialized. This can be easily reproduced by
running xfstests generic/186, which simulate no more credits.

[ 134.351592] BUG: kernel NULL pointer dereference, address: 0000000000000000

[ 134.355341] RIP: 0010:ocfs2_journal_dirty+0x14f/0x160 [ocfs2]

[ 134.365071] Call Trace:
[ 134.365312] <TASK>
[ 134.365524] ? __die_body+0x1e/0x60
[ 134.365868] ? page_fault_oops+0x13d/0x4f0
[ 134.366265] ? __pfx_bit_wait_io+0x10/0x10
[ 134.366659] ? schedule+0x27/0xb0
[ 134.366981] ? exc_page_fault+0x6a/0x140
[ 134.367356] ? asm_exc_page_fault+0x26/0x30
[ 134.367762] ? ocfs2_journal_dirty+0x14f/0x160 [ocfs2]
[ 134.368305] ? ocfs2_journal_dirty+0x13d/0x160 [ocfs2]
[ 134.368837] ocfs2_create_new_meta_bhs.isra.51+0x139/0x2e0 [ocfs2]
[ 134.369454] ocfs2_grow_tree+0x688/0x8a0 [ocfs2]
[ 134.369927] ocfs2_split_and_insert.isra.67+0x35c/0x4a0 [ocfs2]
[ 134.370521] ocfs2_split_extent+0x314/0x4d0 [ocfs2]
[ 134.371019] ocfs2_change_extent_flag+0x174/0x410 [ocfs2]
[ 134.371566] ocfs2_add_refcount_flag+0x3fa/0x630 [ocfs2]
[ 134.372117] ocfs2_reflink_remap_extent+0x21b/0x4c0 [ocfs2]
[ 134.372994] ? inode_update_timestamps+0x4a/0x120
[ 134.373692] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2]
[ 134.374545] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2]
[ 134.375393] ocfs2_reflink_remap_blocks+0xe4/0x4e0 [ocfs2]
[ 134.376197] ocfs2_remap_file_range+0x1de/0x390 [ocfs2]
[ 134.376971] ? security_file_permission+0x29/0x50
[ 134.377644] vfs_clone_file_range+0xfe/0x320
[ 134.378268] ioctl_file_clone+0x45/0xa0
[ 134.378853] do_vfs_ioctl+0x457/0x990
[ 134.379422] __x64_sys_ioctl+0x6e/0xd0
[ 134.379987] do_syscall_64+0x5d/0x170
[ 134.380550] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 134.381231] RIP: 0033:0x7fa4926397cb
[ 134.381786] Code: 73 01 c3 48 8b 0d bd 56 38 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8d 56 38 00 f7 d8 64 89 01 48
[ 134.383930] RSP: 002b:00007ffc2b39f7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 134.384854] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa4926397cb
[ 134.385734] RDX: 00007ffc2b39f7f0 RSI: 000000004020940d RDI: 0000000000000003
[ 134.386606] RBP: 0000000000000000 R08: 00111a82a4f015bb R09: 00007fa494221000
[ 134.387476] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[ 134.388342] R13: 0000000000f10000 R14: 0000558e844e2ac8 R15: 0000000000f10000
[ 134.389207] </TASK>

Fix it by only aborting transaction and journal in ocfs2_journal_dirty()
now, and leave ocfs2_abort() later when detecting an aborted handle,
e.g. start next transaction. Also log the handle details in this case.

AI Score

6.7

Confidence

Low

SSVC

Exploitation

none

Automatable

no

Technical Impact

partial