[v6.6] general protection fault in nilfs_dat_commit_end
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syzbot
May 3, 2026, 4:46:25 PM (11 days ago) May 3
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=142c8ad2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 12715 Comm: segctord Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc9000464f318 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888030180798 RCX: ffff88802b7d9e00
RDX: 0000000000000000 RSI: ffff888030180798 RDI: ffff888059e367d8
RBP: 0000000000000000 R08: ffff888059e49d9f R09: 1ffff1100b3c93b3
R10: dffffc0000000000 R11: ffffed100b3c93b4 R12: ffff888059e367d8
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff8880301807b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb193742000 CR3: 0000000064aff000 CR4: 00000000003506f0
Call Trace:
<TASK>
nilfs_dat_commit_update+0x28/0x40 fs/nilfs2/dat.c:261
nilfs_btree_commit_update_v+0x93/0x410 fs/nilfs2/btree.c:1958
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2031 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2064 [inline]
nilfs_btree_propagate+0x95e/0xcf0 fs/nilfs2/btree.c:2108
nilfs_bmap_propagate+0x74/0x120 fs/nilfs2/bmap.c:345
nilfs_collect_file_data+0x4f/0xd0 fs/nilfs2/segment.c:587
nilfs_segctor_apply_buffers+0x15d/0x320 fs/nilfs2/segment.c:1050
nilfs_segctor_scan_file+0x2a3/0x950 fs/nilfs2/segment.c:1089
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1208 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1535 [inline]
nilfs_segctor_do_construct+0x1b48/0x68a0 fs/nilfs2/segment.c:2091
nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2454
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc9000464f318 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888030180798 RCX: ffff88802b7d9e00
RDX: 0000000000000000 RSI: ffff888030180798 RDI: ffff888059e367d8
RBP: 0000000000000000 R08: ffff888059e49d9f R09: 1ffff1100b3c93b3
R10: dffffc0000000000 R11: ffffed100b3c93b4 R12: ffff888059e367d8
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff8880301807b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb19374f000 CR3: 0000000068c9d000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=142c8ad2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 12715 Comm: segctord Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc9000464f318 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888030180798 RCX: ffff88802b7d9e00
RDX: 0000000000000000 RSI: ffff888030180798 RDI: ffff888059e367d8
RBP: 0000000000000000 R08: ffff888059e49d9f R09: 1ffff1100b3c93b3
R10: dffffc0000000000 R11: ffffed100b3c93b4 R12: ffff888059e367d8
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff8880301807b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb193742000 CR3: 0000000064aff000 CR4: 00000000003506f0
Call Trace:
<TASK>
nilfs_dat_commit_update+0x28/0x40 fs/nilfs2/dat.c:261
nilfs_btree_commit_update_v+0x93/0x410 fs/nilfs2/btree.c:1958
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2031 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2064 [inline]
nilfs_btree_propagate+0x95e/0xcf0 fs/nilfs2/btree.c:2108
nilfs_bmap_propagate+0x74/0x120 fs/nilfs2/bmap.c:345
nilfs_collect_file_data+0x4f/0xd0 fs/nilfs2/segment.c:587
nilfs_segctor_apply_buffers+0x15d/0x320 fs/nilfs2/segment.c:1050
nilfs_segctor_scan_file+0x2a3/0x950 fs/nilfs2/segment.c:1089
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1208 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1535 [inline]
nilfs_segctor_do_construct+0x1b48/0x68a0 fs/nilfs2/segment.c:2091
nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2454
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc9000464f318 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888030180798 RCX: ffff88802b7d9e00
RDX: 0000000000000000 RSI: ffff888030180798 RDI: ffff888059e367d8
RBP: 0000000000000000 R08: ffff888059e49d9f R09: 1ffff1100b3c93b3
R10: dffffc0000000000 R11: ffffed100b3c93b4 R12: ffff888059e367d8
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff8880301807b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb19374f000 CR3: 0000000068c9d000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
May 3, 2026, 8:29:23 PM (11 days ago) May 3
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17e9f326580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/4766c396c75b/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/052200d30ba4/mount_3.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=137d396a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 6114 Comm: segctord Not tainted syzkaller #0
RAX: 0000000000000002 RBX: ffff88805dfa3c18 RCX: ffff8880237b3c00
RDX: 0000000000000000 RSI: ffff88805dfa3c18 RDI: ffff888073b70e28
RBP: 0000000000000000 R08: ffff88805b225ae7 R09: 1ffff1100b644b5c
R10: dffffc0000000000 R11: ffffed100b644b5d R12: ffff888073b70e28
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805dfa3c30
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
RAX: 0000000000000002 RBX: ffff88805dfa3c18 RCX: ffff8880237b3c00
RDX: 0000000000000000 RSI: ffff88805dfa3c18 RDI: ffff888073b70e28
RBP: 0000000000000000 R08: ffff88805b225ae7 R09: 1ffff1100b644b5c
R10: dffffc0000000000 R11: ffffed100b644b5d R12: ffff888073b70e28
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805dfa3c30
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=165c31ce580000
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/052200d30ba4/mount_3.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=137d396a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc90003917318 EFLAGS: 00010202
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RAX: 0000000000000002 RBX: ffff88805dfa3c18 RCX: ffff8880237b3c00
RDX: 0000000000000000 RSI: ffff88805dfa3c18 RDI: ffff888073b70e28
RBP: 0000000000000000 R08: ffff88805b225ae7 R09: 1ffff1100b644b5c
R10: dffffc0000000000 R11: ffffed100b644b5d R12: ffff888073b70e28
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805dfa3c30
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2db44fe000 CR3: 000000002ea1b000 CR4: 00000000003506e0
Call Trace:
<TASK>
nilfs_dat_commit_update+0x28/0x40 fs/nilfs2/dat.c:261
nilfs_btree_commit_update_v+0x93/0x410 fs/nilfs2/btree.c:1958
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2031 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2064 [inline]
nilfs_btree_propagate+0x95e/0xcf0 fs/nilfs2/btree.c:2108
nilfs_bmap_propagate+0x74/0x120 fs/nilfs2/bmap.c:345
nilfs_collect_file_data+0x4f/0xd0 fs/nilfs2/segment.c:587
nilfs_segctor_apply_buffers+0x15d/0x320 fs/nilfs2/segment.c:1050
nilfs_segctor_scan_file+0x6db/0x950 fs/nilfs2/segment.c:1099
<TASK>
nilfs_dat_commit_update+0x28/0x40 fs/nilfs2/dat.c:261
nilfs_btree_commit_update_v+0x93/0x410 fs/nilfs2/btree.c:1958
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2031 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2064 [inline]
nilfs_btree_propagate+0x95e/0xcf0 fs/nilfs2/btree.c:2108
nilfs_bmap_propagate+0x74/0x120 fs/nilfs2/bmap.c:345
nilfs_collect_file_data+0x4f/0xd0 fs/nilfs2/segment.c:587
nilfs_segctor_apply_buffers+0x15d/0x320 fs/nilfs2/segment.c:1050
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1208 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1535 [inline]
nilfs_segctor_do_construct+0x1b48/0x68a0 fs/nilfs2/segment.c:2091
nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2454
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc90003917318 EFLAGS: 00010202
nilfs_segctor_collect fs/nilfs2/segment.c:1535 [inline]
nilfs_segctor_do_construct+0x1b48/0x68a0 fs/nilfs2/segment.c:2091
nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2454
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RAX: 0000000000000002 RBX: ffff88805dfa3c18 RCX: ffff8880237b3c00
RDX: 0000000000000000 RSI: ffff88805dfa3c18 RDI: ffff888073b70e28
RBP: 0000000000000000 R08: ffff88805b225ae7 R09: 1ffff1100b644b5c
R10: dffffc0000000000 R11: ffffed100b644b5d R12: ffff888073b70e28
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805dfa3c30
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e5cd759a0 CR3: 000000002ea1b000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
If you want syzbot to run the reproducer, reply with:
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
syzbot
May 4, 2026, 12:15:32 AM (10 days ago) May 4
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15eaf76c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14de576c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c24236c61b70/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 6052 Comm: segctord Not tainted syzkaller #0
RAX: 0000000000000002 RBX: ffff88805c817098 RCX: ffff88802b3a1e00
RDX: 0000000000000000 RSI: ffff88805c817098 RDI: ffff8880609ac168
RBP: 0000000000000000 R08: ffff8880737d51d7 R09: 1ffff1100e6faa3a
R10: dffffc0000000000 R11: ffffed100e6faa3b R12: ffff8880609ac168
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805c8170b0
RSP: 0018:ffffc900037b7318 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88805c817098 RCX: ffff88802b3a1e00
RDX: 0000000000000000 RSI: ffff88805c817098 RDI: ffff8880609ac168
RBP: 0000000000000000 R08: ffff8880737d51d7 R09: 1ffff1100e6faa3a
R10: dffffc0000000000 R11: ffffed100e6faa3b R12: ffff8880609ac168
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805c8170b0
HEAD commit: 258cf62a6dfd Linux 6.6.137
git tree: linux-6.6.y
kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128b396a580000
dashboard link: https://syzkaller.appspot.com/bug?extid=89f246a6312804084d2f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14de576c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8abd93876bdd/disk-258cf62a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/721d0cc7467a/vmlinux-258cf62a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7f2dfd911e3d/bzImage-258cf62a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f246...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RSP: 0018:ffffc900037b7318 EFLAGS: 00010202
RIP: 0010:nilfs_dat_commit_end+0x58/0x6b0 fs/nilfs2/dat.c:205
Code: 18 4c 89 f8 48 c1 e8 03 48 89 44 24 08 42 80 3c 28 00 74 08 4c 89 ff e8 06 6b 98 fe 4d 8b 37 49 83 c6 10 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 e9 6a 98 fe 4d 8b 36 bf 01 00 00
RAX: 0000000000000002 RBX: ffff88805c817098 RCX: ffff88802b3a1e00
RDX: 0000000000000000 RSI: ffff88805c817098 RDI: ffff8880609ac168
RBP: 0000000000000000 R08: ffff8880737d51d7 R09: 1ffff1100e6faa3a
R10: dffffc0000000000 R11: ffffed100e6faa3b R12: ffff8880609ac168
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805c8170b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555796914e8 CR3: 0000000030b72000 CR4: 00000000003506f0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
RAX: 0000000000000002 RBX: ffff88805c817098 RCX: ffff88802b3a1e00
RDX: 0000000000000000 RSI: ffff88805c817098 RDI: ffff8880609ac168
RBP: 0000000000000000 R08: ffff8880737d51d7 R09: 1ffff1100e6faa3a
R10: dffffc0000000000 R11: ffffed100e6faa3b R12: ffff8880609ac168
R13: dffffc0000000000 R14: 0000000000000010 R15: ffff88805c8170b0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555796914e8 CR3: 0000000019689000 CR4: 00000000003506f0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
----------------
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
Code disassembly (best guess):
0: 18 4c 89 f8 sbb %cl,-0x8(%rcx,%rcx,4)
4: 48 c1 e8 03 shr $0x3,%rax
8: 48 89 44 24 08 mov %rax,0x8(%rsp)
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 06 6b 98 fe call 0xfe986b22
1c: 4d 8b 37 mov (%r15),%r14
1f: 49 83 c6 10 add $0x10,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 e9 6a 98 fe call 0xfe986b22
39: 4d 8b 36 mov (%r14),%r14
3c: bf .byte 0xbf
3d: 01 00 add %eax,(%rax)
---
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