The patch titled Subject: ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty() has been added to the -mm mm-hotfixes-unstable branch. Its filename is ocfs2-fix-null-pointer-dereference-in-ocfs2_journal_dirty.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-fix-null-pointer-dereference-in-ocfs2_journal_dirty.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Subject: ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty() Date: Thu, 30 May 2024 19:06:29 +0800 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. Link: https://lkml.kernel.org/r/20240530110630.3933832-1-joseph.qi@xxxxxxxxxxxxxxxxx Fixes: 8887b94d9322 ("ocfs2: stop using bdev->bd_super for journal error logging") Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Changwei Ge <gechangwei@xxxxxxx> Cc: Gang He <ghe@xxxxxxxx> Cc: Jun Piao <piaojun@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [6.6+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/journal.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/fs/ocfs2/journal.c~ocfs2-fix-null-pointer-dereference-in-ocfs2_journal_dirty +++ a/fs/ocfs2/journal.c @@ -778,13 +778,15 @@ void ocfs2_journal_dirty(handle_t *handl if (!is_handle_aborted(handle)) { journal_t *journal = handle->h_transaction->t_journal; - mlog(ML_ERROR, "jbd2_journal_dirty_metadata failed. " - "Aborting transaction and journal.\n"); + mlog(ML_ERROR, "jbd2_journal_dirty_metadata failed: " + "handle type %u started at line %u, credits %u/%u " + "errcode %d. Aborting transaction and journal.\n", + handle->h_type, handle->h_line_no, + handle->h_requested_credits, + jbd2_handle_buffer_credits(handle), status); handle->h_err = status; jbd2_journal_abort_handle(handle); jbd2_journal_abort(journal, status); - ocfs2_abort(bh->b_assoc_map->host->i_sb, - "Journal already aborted.\n"); } } } _ Patches currently in -mm which might be from joseph.qi@xxxxxxxxxxxxxxxxx are ocfs2-fix-null-pointer-dereference-in-ocfs2_journal_dirty.patch ocfs2-fix-null-pointer-dereference-in-ocfs2_abort_trigger.patch