[moderation] [bcachefs?] BUG: unable to handle kernel paging request in bch2_btree_iter_peek_slot
5 views
Skip to first unread message
syzbot
Jul 18, 2025, 8:07:40 AM7/18/25
to syzkaller-upst...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 0be23810e32e Add linux-next specific files for 20250714
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15ad0382580000
kernel config: https://syzkaller.appspot.com/x/.config?x=adc3ea2bfe31343b
dashboard link: https://syzkaller.appspot.com/bug?extid=9b1a141ade7c466cf963
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
CC: [kent.ov...@linux.dev linux-b...@vger.kernel.org linux-...@vger.kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/13b5be5048fe/disk-0be23810.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3d2b3b2ceddf/vmlinux-0be23810.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c7e5fbf3efa6/bzImage-0be23810.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b1a14...@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: fffffffffffff774
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD df3d067 P4D df3d067 PUD df3f067 PMD 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 13517 Comm: syz.0.1053 Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:bch2_btree_iter_peek_slot+0xb13/0x22f0 fs/bcachefs/btree_iter.c:2872
Code: 85 40 09 00 00 e8 ed ed 96 fd 48 8b 9c 24 f8 00 00 00 48 83 c3 02 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 10 00 00 <0f> b6 1b bf 01 00 00 00 89 de e8 be f0 96 fd 83 fb 01 0f 85 5e 02
RSP: 0018:ffffc9000b0254e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffff774 RCX: 0000000000080000
RDX: ffffc9001189f000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000b025790 R08: ffff88806ab7bc00 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000002 R12: ffffc9000b025920
R13: dffffc0000000000 R14: fffffffffffff772 R15: 0000000000000000
FS: 00007f35899f66c0(0000) GS:ffff888125bed000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffff774 CR3: 00000000592cc000 CR4: 00000000003526f0
Call Trace:
<TASK>
bch2_btree_iter_peek_max_type fs/bcachefs/btree_iter.h:748 [inline]
bch2_bucket_alloc_early+0xf56/0x1680 fs/bcachefs/alloc_foreground.c:310
bch2_bucket_alloc_trans+0x19df/0x1d50 fs/bcachefs/alloc_foreground.c:546
bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:729
__open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:926
open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:958
bch2_alloc_sectors_start_trans+0xe24/0x1e80 fs/bcachefs/alloc_foreground.c:1286
__bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:323 [inline]
bch2_btree_reserve_get+0x55d/0x15d0 fs/bcachefs/btree_update_interior.c:531
bch2_btree_update_start+0x147b/0x1de0 fs/bcachefs/btree_update_interior.c:1267
bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1918
bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:922
__bch2_trans_commit+0x1bb2/0x8a90 fs/bcachefs/btree_trans_commit.c:1139
bch2_trans_commit fs/bcachefs/btree_update.h:270 [inline]
btree_key_cache_flush_pos fs/bcachefs/btree_key_cache.c:483 [inline]
bch2_btree_key_cache_journal_flush+0x907/0xd30 fs/bcachefs/btree_key_cache.c:563
journal_flush_pins+0x8e3/0xe90 fs/bcachefs/journal_reclaim.c:604
journal_flush_pins_or_still_flushing fs/bcachefs/journal_reclaim.c:871 [inline]
journal_flush_done+0x112/0x810 fs/bcachefs/journal_reclaim.c:889
bch2_journal_flush_pins+0x1b5/0x250 fs/bcachefs/journal_reclaim.c:921
bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
bch2_journal_replay+0x2327/0x2630 fs/bcachefs/recovery.c:476
bch2_fs_initialize+0x799/0xe80 fs/bcachefs/recovery.c:1238
bch2_fs_start+0xa67/0xd20 fs/bcachefs/super.c:1241
bch2_fs_get_tree+0xb39/0x1540 fs/bcachefs/fs.c:2494
vfs_get_tree+0x8f/0x2b0 fs/super.c:1804
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f358bb900ca
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f35899f5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35899f5ef0 RCX: 00007f358bb900ca
RDX: 0000200000000140 RSI: 0000200000000000 RDI: 00007f35899f5eb0
RBP: 0000200000000140 R08: 00007f35899f5ef0 R09: 0000000000200414
R10: 0000000000200414 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f35899f5eb0 R14: 0000000000005ad0 R15: 0000200000000400
</TASK>
Modules linked in:
CR2: fffffffffffff774
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_btree_iter_peek_slot+0xb13/0x22f0 fs/bcachefs/btree_iter.c:2872
Code: 85 40 09 00 00 e8 ed ed 96 fd 48 8b 9c 24 f8 00 00 00 48 83 c3 02 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 10 00 00 <0f> b6 1b bf 01 00 00 00 89 de e8 be f0 96 fd 83 fb 01 0f 85 5e 02
RSP: 0018:ffffc9000b0254e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffff774 RCX: 0000000000080000
RDX: ffffc9001189f000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000b025790 R08: ffff88806ab7bc00 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000002 R12: ffffc9000b025920
R13: dffffc0000000000 R14: fffffffffffff772 R15: 0000000000000000
FS: 00007f35899f66c0(0000) GS:ffff888125bed000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffff774 CR3: 00000000592cc000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 85 40 09 test %eax,0x9(%rax)
3: 00 00 add %al,(%rax)
5: e8 ed ed 96 fd call 0xfd96edf7
a: 48 8b 9c 24 f8 00 00 mov 0xf8(%rsp),%rbx
11: 00
12: 48 83 c3 02 add $0x2,%rbx
16: 48 89 d8 mov %rbx,%rax
19: 48 c1 e8 03 shr $0x3,%rax
1d: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
22: 84 c0 test %al,%al
24: 0f 85 14 10 00 00 jne 0x103e
* 2a: 0f b6 1b movzbl (%rbx),%ebx <-- trapping instruction
2d: bf 01 00 00 00 mov $0x1,%edi
32: 89 de mov %ebx,%esi
34: e8 be f0 96 fd call 0xfd96f0f7
39: 83 fb 01 cmp $0x1,%ebx
3c: 0f .byte 0xf
3d: 85 5e 02 test %ebx,0x2(%rsi)
---
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: 0be23810e32e Add linux-next specific files for 20250714
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15ad0382580000
kernel config: https://syzkaller.appspot.com/x/.config?x=adc3ea2bfe31343b
dashboard link: https://syzkaller.appspot.com/bug?extid=9b1a141ade7c466cf963
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
CC: [kent.ov...@linux.dev linux-b...@vger.kernel.org linux-...@vger.kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/13b5be5048fe/disk-0be23810.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3d2b3b2ceddf/vmlinux-0be23810.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c7e5fbf3efa6/bzImage-0be23810.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b1a14...@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: fffffffffffff774
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD df3d067 P4D df3d067 PUD df3f067 PMD 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 13517 Comm: syz.0.1053 Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:bch2_btree_iter_peek_slot+0xb13/0x22f0 fs/bcachefs/btree_iter.c:2872
Code: 85 40 09 00 00 e8 ed ed 96 fd 48 8b 9c 24 f8 00 00 00 48 83 c3 02 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 10 00 00 <0f> b6 1b bf 01 00 00 00 89 de e8 be f0 96 fd 83 fb 01 0f 85 5e 02
RSP: 0018:ffffc9000b0254e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffff774 RCX: 0000000000080000
RDX: ffffc9001189f000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000b025790 R08: ffff88806ab7bc00 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000002 R12: ffffc9000b025920
R13: dffffc0000000000 R14: fffffffffffff772 R15: 0000000000000000
FS: 00007f35899f66c0(0000) GS:ffff888125bed000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffff774 CR3: 00000000592cc000 CR4: 00000000003526f0
Call Trace:
<TASK>
bch2_btree_iter_peek_max_type fs/bcachefs/btree_iter.h:748 [inline]
bch2_bucket_alloc_early+0xf56/0x1680 fs/bcachefs/alloc_foreground.c:310
bch2_bucket_alloc_trans+0x19df/0x1d50 fs/bcachefs/alloc_foreground.c:546
bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:729
__open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:926
open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:958
bch2_alloc_sectors_start_trans+0xe24/0x1e80 fs/bcachefs/alloc_foreground.c:1286
__bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:323 [inline]
bch2_btree_reserve_get+0x55d/0x15d0 fs/bcachefs/btree_update_interior.c:531
bch2_btree_update_start+0x147b/0x1de0 fs/bcachefs/btree_update_interior.c:1267
bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1918
bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:922
__bch2_trans_commit+0x1bb2/0x8a90 fs/bcachefs/btree_trans_commit.c:1139
bch2_trans_commit fs/bcachefs/btree_update.h:270 [inline]
btree_key_cache_flush_pos fs/bcachefs/btree_key_cache.c:483 [inline]
bch2_btree_key_cache_journal_flush+0x907/0xd30 fs/bcachefs/btree_key_cache.c:563
journal_flush_pins+0x8e3/0xe90 fs/bcachefs/journal_reclaim.c:604
journal_flush_pins_or_still_flushing fs/bcachefs/journal_reclaim.c:871 [inline]
journal_flush_done+0x112/0x810 fs/bcachefs/journal_reclaim.c:889
bch2_journal_flush_pins+0x1b5/0x250 fs/bcachefs/journal_reclaim.c:921
bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
bch2_journal_replay+0x2327/0x2630 fs/bcachefs/recovery.c:476
bch2_fs_initialize+0x799/0xe80 fs/bcachefs/recovery.c:1238
bch2_fs_start+0xa67/0xd20 fs/bcachefs/super.c:1241
bch2_fs_get_tree+0xb39/0x1540 fs/bcachefs/fs.c:2494
vfs_get_tree+0x8f/0x2b0 fs/super.c:1804
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f358bb900ca
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f35899f5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35899f5ef0 RCX: 00007f358bb900ca
RDX: 0000200000000140 RSI: 0000200000000000 RDI: 00007f35899f5eb0
RBP: 0000200000000140 R08: 00007f35899f5ef0 R09: 0000000000200414
R10: 0000000000200414 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f35899f5eb0 R14: 0000000000005ad0 R15: 0000200000000400
</TASK>
Modules linked in:
CR2: fffffffffffff774
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_btree_iter_peek_slot+0xb13/0x22f0 fs/bcachefs/btree_iter.c:2872
Code: 85 40 09 00 00 e8 ed ed 96 fd 48 8b 9c 24 f8 00 00 00 48 83 c3 02 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 10 00 00 <0f> b6 1b bf 01 00 00 00 89 de e8 be f0 96 fd 83 fb 01 0f 85 5e 02
RSP: 0018:ffffc9000b0254e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: fffffffffffff774 RCX: 0000000000080000
RDX: ffffc9001189f000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000b025790 R08: ffff88806ab7bc00 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000002 R12: ffffc9000b025920
R13: dffffc0000000000 R14: fffffffffffff772 R15: 0000000000000000
FS: 00007f35899f66c0(0000) GS:ffff888125bed000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffff774 CR3: 00000000592cc000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 85 40 09 test %eax,0x9(%rax)
3: 00 00 add %al,(%rax)
5: e8 ed ed 96 fd call 0xfd96edf7
a: 48 8b 9c 24 f8 00 00 mov 0xf8(%rsp),%rbx
11: 00
12: 48 83 c3 02 add $0x2,%rbx
16: 48 89 d8 mov %rbx,%rax
19: 48 c1 e8 03 shr $0x3,%rax
1d: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
22: 84 c0 test %al,%al
24: 0f 85 14 10 00 00 jne 0x103e
* 2a: 0f b6 1b movzbl (%rbx),%ebx <-- trapping instruction
2d: bf 01 00 00 00 mov $0x1,%edi
32: 89 de mov %ebx,%esi
34: e8 be f0 96 fd call 0xfd96f0f7
39: 83 fb 01 cmp $0x1,%ebx
3c: 0f .byte 0xf
3d: 85 5e 02 test %ebx,0x2(%rsi)
---
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
Sep 21, 2025, 4:47:16 AM9/21/25
to syzkaller-upst...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
Reply all
Reply to author
Forward
0 new messages