kernel/linux.git/fs/ext4/fast_commit.c, branch v5.10.257

ext4: publish jinode after initialization

2026-04-18T08:31:16+00:00

[ Upstream commit 1aec30021edd410b986c156f195f3d23959a9d11 ] ext4_inode_attach_jinode() publishes ei->jinode to concurrent users. It used to set ei->jinode before jbd2_journal_init_jbd_inode(), allowing a reader to observe a non-NULL jinode with i_vfs_inode still unset. The fast commit flush path can then pass this jinode to jbd2_wait_inode_data(), which dereferences i_vfs_inode->i_mapping and may crash. Below is the crash I observe: ``` BUG: unable to handle page fault for address: 000000010beb47f4 PGD 110e51067 P4D 110e51067 PUD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 4850 Comm: fc_fsync_bench_ Not tainted 6.18.0-00764-g795a690c06a5 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 RIP: 0010:xas_find_marked+0x3d/0x2e0 Code: e0 03 48 83 f8 02 0f 84 f0 01 00 00 48 8b 47 08 48 89 c3 48 39 c6 0f 82 fd 01 00 00 48 85 c9 74 3d 48 83 f9 03 77 63 4c 8b 0f <49> 8b 71 08 48 c7 47 18 00 00 00 00 48 89 f1 83 e1 03 48 83 f9 02 RSP: 0018:ffffbbee806e7bf0 EFLAGS: 00010246 RAX: 000000000010beb4 RBX: 000000000010beb4 RCX: 0000000000000003 RDX: 0000000000000001 RSI: 0000002000300000 RDI: ffffbbee806e7c10 RBP: 0000000000000001 R08: 0000002000300000 R09: 000000010beb47ec R10: ffff9ea494590090 R11: 0000000000000000 R12: 0000002000300000 R13: ffffbbee806e7c90 R14: ffff9ea494513788 R15: ffffbbee806e7c88 FS: 00007fc2f9e3e6c0(0000) GS:ffff9ea6b1444000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000010beb47f4 CR3: 0000000119ac5000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: filemap_get_folios_tag+0x87/0x2a0 __filemap_fdatawait_range+0x5f/0xd0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __schedule+0x3e7/0x10c0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? cap_safe_nice+0x37/0x70 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 filemap_fdatawait_range_keep_errors+0x12/0x40 ext4_fc_commit+0x697/0x8b0 ? ext4_file_write_iter+0x64b/0x950 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? vfs_write+0x356/0x480 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ext4_sync_file+0xf7/0x370 do_fsync+0x3b/0x80 ? syscall_trace_enter+0x108/0x1d0 __x64_sys_fdatasync+0x16/0x20 do_syscall_64+0x62/0x2c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ... ``` Fix this by initializing the jbd2_inode first. Use smp_wmb() and WRITE_ONCE() to publish ei->jinode after initialization. Readers use READ_ONCE() to fetch the pointer. Fixes: a361293f5fede ("jbd2: Fix oops in jbd2_journal_file_inode()") Cc: stable@vger.kernel.org Signed-off-by: Li Chen Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260225082617.147957-1-me@linux.beauty Signed-off-by: Theodore Ts'o Cc: stable@kernel.org [ adapted READ_ONCE(jinode) wrapping to split ext4_fc_submit_inode_data_all() and ext4_fc_wait_inode_data_all() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths

2026-04-18T08:31:16+00:00

[ Upstream commit ec0a7500d8eace5b4f305fa0c594dd148f0e8d29 ] During code review, Joseph found that ext4_fc_replay_inode() calls ext4_get_fc_inode_loc() to get the inode location, which holds a reference to iloc.bh that must be released via brelse(). However, several error paths jump to the 'out' label without releasing iloc.bh: - ext4_handle_dirty_metadata() failure - sync_dirty_buffer() failure - ext4_mark_inode_used() failure - ext4_iget() failure Fix this by introducing an 'out_brelse' label placed just before the existing 'out' label to ensure iloc.bh is always released. Additionally, make ext4_fc_replay_inode() propagate errors properly instead of always returning 0. Reported-by: Joseph Qi Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260323060836.3452660-1-libaokun@linux.alibaba.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ext4: don't set up encryption key during jbd2 transaction

2023-01-14T09:16:51+00:00

commit 4c0d5778385cb3618ff26a561ce41de2b7d9de70 upstream. Commit a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature") extended the scope of the transaction in ext4_unlink() too far, making it include the call to ext4_find_entry(). However, ext4_find_entry() can deadlock when called from within a transaction because it may need to set up the directory's encryption key. Fix this by restoring the transaction to its original scope. Reported-by: syzbot+1a748d0007eeac3ab079@syzkaller.appspotmail.com Fixes: a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-3-ebiggers@kernel.org Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: disable fast-commit of encrypted dir operations

2023-01-14T09:16:51+00:00

commit 0fbcb5251fc81b58969b272c4fb7374a7b922e3e upstream. fast-commit of create, link, and unlink operations in encrypted directories is completely broken because the unencrypted filenames are being written to the fast-commit journal instead of the encrypted filenames. These operations can't be replayed, as encryption keys aren't present at journal replay time. It is also an information leak. Until if/when we can get this working properly, make encrypted directory operations ineligible for fast-commit. Note that fast-commit operations on encrypted regular files continue to be allowed, as they seem to work. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-2-ebiggers@kernel.org Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix leaking uninitialized memory in fast-commit journal

2023-01-14T09:16:43+00:00

[ Upstream commit 594bc43b410316d70bb42aeff168837888d96810 ] When space at the end of fast-commit journal blocks is unused, make sure to zero it out so that uninitialized memory is not leaked to disk. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-4-ebiggers@kernel.org Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: fix various seppling typos

2023-01-14T09:16:43+00:00

[ Upstream commit 3088e5a5153cda27ec26461e5edf2821e15e802c ] Signed-off-by: Bhaskar Chowdhury Link: https://lore.kernel.org/r/cover.1616840203.git.unixbhaskar@gmail.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: update 'state->fc_regions_size' after successful memory allocation

2022-10-26T11:25:14+00:00

commit 27cd49780381c6ccbf248798e5e8fd076200ffba upstream. To avoid to 'state->fc_regions_size' mismatch with 'state->fc_regions' when fail to reallocate 'fc_reqions',only update 'state->fc_regions_size' after 'state->fc_regions' is allocated successfully. Cc: stable@kernel.org Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220921064040.3693255-4-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix potential memory leak in ext4_fc_record_regions()

2022-10-26T11:25:14+00:00

commit 7069d105c1f15c442b68af43f7fde784f3126739 upstream. As krealloc may return NULL, in this case 'state->fc_regions' may not be freed by krealloc, but 'state->fc_regions' already set NULL. Then will lead to 'state->fc_regions' memory leak. Cc: stable@kernel.org Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220921064040.3693255-3-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix potential memory leak in ext4_fc_record_modified_inode()

2022-10-26T11:25:14+00:00

commit 9305721a309fa1bd7c194e0d4a2335bf3b29dca4 upstream. As krealloc may return NULL, in this case 'state->fc_modified_inodes' may not be freed by krealloc, but 'state->fc_modified_inodes' already set NULL. Then will lead to 'state->fc_modified_inodes' memory leak. Cc: stable@kernel.org Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220921064040.3693255-2-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix miss release buffer head in ext4_fc_write_inode

2022-10-26T11:25:14+00:00

commit ccbf8eeb39f2ff00b54726a2b20b35d788c4ecb5 upstream. In 'ext4_fc_write_inode' function first call 'ext4_get_inode_loc' get 'iloc', after use it miss release 'iloc.bh'. So just release 'iloc.bh' before 'ext4_fc_write_inode' return. Cc: stable@kernel.org Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220914100859.1415196-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman