kernel BUG in ext4_write_inline_data

[Ahmet Eray Karadag]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+f3185b...@syzkaller.appspotmail.com
Tested-by: syzbot+f3185b...@syzkaller.appspotmail.com

Tested on:

commit: a8cdf51c Merge tag 'hardening-fix1-v6.18-rc1' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=139b5458580000
kernel config: https://syzkaller.appspot.com/x/.config?x=18b333076bdf1c20
dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=166b7334580000

Note: testing is done by a robot and is best-effort only.

[ALBIN BABU VARGHESE]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+f3185b...@syzkaller.appspotmail.com
Tested-by: syzbot+f3185b...@syzkaller.appspotmail.com

Tested on:

commit: cd5a0afb Merge tag 'mailbox-v6.18' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ce3a7c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=513361ac097cb4a5

dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=14ea4542580000

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in __ext4_journal_stop

------------[ cut here ]------------
kernel BUG at fs/ext4/ext4_jbd2.c:54!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 7268 Comm: syz.3.141 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:54 [inline]
RIP: 0010:__ext4_journal_stop+0x191/0x1a0 fs/ext4/ext4_jbd2.c:126
Code: e8 e4 3e 50 ff e9 f8 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff e8 ba ee b5 ff e9 06 ff ff ff e8 c0 3e 50 ff 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b107840 EFLAGS: 00010293
RAX: ffffffff826f6420 RBX: 0000000000000000 RCX: ffff88802e085ac0
RDX: 0000000000000000 RSI: 0000000000000361 RDI: ffffffff8d5e2286
RBP: ffffc9000b107968 R08: ffffea000175b077 R09: 1ffffd40002eb60e
R10: dffffc0000000000 R11: fffff940002eb60f R12: 0000000000000078
R13: 0000000000000361 R14: ffffffff8d5e2286 R15: ffff888074bb6bc8
FS: 00007ff117be16c0(0000) GS:ffff88812646b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555564fe588 CR3: 00000000546e9000 CR4: 0000000000350ef0
Call Trace:
<TASK>
ext4_write_inline_data_end+0x7a9/0xab0 fs/ext4/inline.c:865
generic_perform_write+0x62a/0x900 mm/filemap.c:4263
ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff116d8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff117be1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff116fe5fa0 RCX: 00007ff116d8eec9
RDX: 0000000000000078 RSI: 0000200000000600 RDI: 0000000000000005
RBP: 00007ff116e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff116fe6038 R14: 00007ff116fe5fa0 R15: 00007ffd5125ed68
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:54 [inline]
RIP: 0010:__ext4_journal_stop+0x191/0x1a0 fs/ext4/ext4_jbd2.c:126
Code: e8 e4 3e 50 ff e9 f8 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff e8 ba ee b5 ff e9 06 ff ff ff e8 c0 3e 50 ff 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b107840 EFLAGS: 00010293
RAX: ffffffff826f6420 RBX: 0000000000000000 RCX: ffff88802e085ac0
RDX: 0000000000000000 RSI: 0000000000000361 RDI: ffffffff8d5e2286
RBP: ffffc9000b107968 R08: ffffea000175b077 R09: 1ffffd40002eb60e
R10: dffffc0000000000 R11: fffff940002eb60f R12: 0000000000000078
R13: 0000000000000361 R14: ffffffff8d5e2286 R15: ffff888074bb6bc8
FS: 00007ff117be16c0(0000) GS:ffff88812636b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555593914808 CR3: 00000000546e9000 CR4: 0000000000350ef0


Tested on:

commit: f406055c Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=173b2b04580000
kernel config: https://syzkaller.appspot.com/x/.config?x=308983f9c02338e8

dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=17b5767c580000

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in __ext4_journal_stop

------------[ cut here ]------------
kernel BUG at fs/ext4/ext4_jbd2.c:54!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI

CPU: 1 UID: 0 PID: 7077 Comm: syz.2.139 Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:54 [inline]
RIP: 0010:__ext4_journal_stop+0x191/0x1a0 fs/ext4/ext4_jbd2.c:126

Code: e8 f4 39 50 ff e9 f8 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff e8 ba ee b5 ff e9 06 ff ff ff e8 d0 39 50 ff 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90005097840 EFLAGS: 00010293
RAX: ffffffff826f68f0 RBX: 0000000000000000 RCX: ffff88802c95bc80
RDX: 0000000000000000 RSI: 000000000000034f RDI: ffffffff8d5e1065
RBP: ffffc90005097968 R08: ffffea0001c01337 R09: 1ffffd4000380266
R10: dffffc0000000000 R11: fffff94000380267 R12: 0000000000000078
R13: 000000000000034f R14: ffffffff8d5e1065 R15: ffff888072ba0298
FS: 00007fbd8db566c0(0000) GS:ffff88812646d000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000200000000674 CR3: 000000005d163000 CR4: 0000000000350ef0
Call Trace:
<TASK>
ext4_write_inline_data_end+0x7a9/0xab0 fs/ext4/inline.c:847

generic_perform_write+0x62a/0x900 mm/filemap.c:4263
ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7fbd8cd8eec9

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007fbd8db56038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbd8cfe5fa0 RCX: 00007fbd8cd8eec9

RDX: 0000000000000078 RSI: 0000200000000600 RDI: 0000000000000005

RBP: 00007fbd8ce11f91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fbd8cfe6038 R14: 00007fbd8cfe5fa0 R15: 00007ffdf5505328

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:54 [inline]
RIP: 0010:__ext4_journal_stop+0x191/0x1a0 fs/ext4/ext4_jbd2.c:126

Code: e8 f4 39 50 ff e9 f8 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff e8 ba ee b5 ff e9 06 ff ff ff e8 d0 39 50 ff 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90005097840 EFLAGS: 00010293
RAX: ffffffff826f68f0 RBX: 0000000000000000 RCX: ffff88802c95bc80
RDX: 0000000000000000 RSI: 000000000000034f RDI: ffffffff8d5e1065
RBP: ffffc90005097968 R08: ffffea0001c01337 R09: 1ffffd4000380266
R10: dffffc0000000000 R11: fffff94000380267 R12: 0000000000000078
R13: 000000000000034f R14: ffffffff8d5e1065 R15: ffff888072ba0298
FS: 00007fbd8db566c0(0000) GS:ffff88812636d000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fab1c171880 CR3: 000000005d163000 CR4: 0000000000350ef0


Tested on:

commit: 211ddde0 Linux 6.18-rc2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113e8de2580000

kernel config: https://syzkaller.appspot.com/x/.config?x=308983f9c02338e8
dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=15536b04580000

[ALBIN BABU VARGHESE]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+f3185b...@syzkaller.appspotmail.com
Tested-by: syzbot+f3185b...@syzkaller.appspotmail.com

Tested on:

commit: 4ea7c171 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=110d30b4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2c614fa9e6f5bdc1

dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=122a7084580000

[ALBIN BABU VARGHESE]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:

WARNING in ext4_dirty_folio

------------[ cut here ]------------
WARNING: CPU: 1 PID: 16600 at fs/ext4/inode.c:3964 ext4_dirty_folio+0x172/0x1b0 fs/ext4/inode.c:3964
Modules linked in:
CPU: 1 UID: 0 PID: 16600 Comm: syz-executor314 Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025

RIP: 0010:ext4_dirty_folio+0x172/0x1b0 fs/ext4/inode.c:3964
Code: 74 7f 47 ff 4c 89 e7 48 89 de 5b 41 5c 41 5d 41 5e 41 5f 5d e9 3f 2b d0 ff e8 5a 7f 47 ff 90 0f 0b 90 eb e0 e8 4f 7f 47 ff 90 <0f> 0b 90 eb a7 e8 44 7f 47 ff 48 89 df 48 c7 c6 60 a3 5e 8b e8 a5
RSP: 0018:ffffc9000489f368 EFLAGS: 00010293
RAX: ffffffff82782371 RBX: ffffea0001b6ce40 RCX: ffff888029725ac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffffd400036d9c8 R08: ffffea0001b6ce47 R09: 1ffffd400036d9c8
R10: dffffc0000000000 R11: fffff9400036d9c9 R12: ffff888052670e48
R13: 1ffffd400036d9c9 R14: 0000000000000000 R15: ffffea0001b6ce48
FS: 0000000000000000(0000) GS:ffff88812646a000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fcd1dfa7000 CR3: 0000000030d2d000 CR4: 0000000000350ef0
Call Trace:
<TASK>
zap_present_folio_ptes mm/memory.c:1629 [inline]
zap_present_ptes mm/memory.c:1709 [inline]
do_zap_pte_range mm/memory.c:1810 [inline]
zap_pte_range mm/memory.c:1854 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x17c9/0x4370 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc152b11b89
Code: Unable to access opcode bytes at 0x7fc152b11b5f.
RSP: 002b:00007fc152aa4178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc152b9a718 RCX: 00007fc152b11b89
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc152b9a718
RBP: 00007fc152b9a710 R08: 00007fc152aa46c0 R09: 00007fc152aa46c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc152b9a71c
R13: 000000000000006e R14: 00007ffeb6196c60 R15: 00007ffeb6196d48
</TASK>


Tested on:

commit: 4427259c Merge tag 'riscv-for-linus-6.18-rc6' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1506a7cd980000

kernel config: https://syzkaller.appspot.com/x/.config?x=2c614fa9e6f5bdc1
dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=107cf17c580000

[ALBIN BABU VARGHESE]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in ext4_dirty_folio

------------[ cut here ]------------

WARNING: CPU: 1 PID: 19829 at fs/ext4/inode.c:3964 ext4_dirty_folio+0x172/0x1b0 fs/ext4/inode.c:3964
Modules linked in:
CPU: 1 UID: 0 PID: 19829 Comm: syz-executor822 Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:ext4_dirty_folio+0x172/0x1b0 fs/ext4/inode.c:3964
Code: 74 7f 47 ff 4c 89 e7 48 89 de 5b 41 5c 41 5d 41 5e 41 5f 5d e9 3f 2b d0 ff e8 5a 7f 47 ff 90 0f 0b 90 eb e0 e8 4f 7f 47 ff 90 <0f> 0b 90 eb a7 e8 44 7f 47 ff 48 89 df 48 c7 c6 60 a3 5e 8b e8 a5

RSP: 0018:ffffc9000d1d7368 EFLAGS: 00010293
RAX: ffffffff82782371 RBX: ffffea0001557e80 RCX: ffff888024e5dac0

RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000

RBP: 1ffffd40002aafd0 R08: ffffea0001557e87 R09: 1ffffd40002aafd0
R10: dffffc0000000000 R11: fffff940002aafd1 R12: ffff88806060ede8
R13: 1ffffd40002aafd1 R14: 0000000000000000 R15: ffffea0001557e88

FS: 0000000000000000(0000) GS:ffff88812646a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fa65112e498 CR3: 000000005edfa000 CR4: 0000000000350ef0

RIP: 0033:0x7fa6510dab89
Code: Unable to access opcode bytes at 0x7fa6510dab5f.
RSP: 002b:00007fa65106d178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa651163718 RCX: 00007fa6510dab89
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa651163718
RBP: 00007fa651163710 R08: 00007fa65106d6c0 R09: 00007fa65106d6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa65116371c
R13: 000000000000006e R14: 00007ffc0f4ff620 R15: 00007ffc0f4ff708

</TASK>


Tested on:

commit: 4427259c Merge tag 'riscv-for-linus-6.18-rc6' of git:/..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=1044b0b4580000

kernel config: https://syzkaller.appspot.com/x/.config?x=2c614fa9e6f5bdc1
dashboard link: https://syzkaller.appspot.com/bug?extid=f3185be57d7e8dda32b8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=1771a7cd980000