[syzbot] [bcachefs?] kernel BUG in bch2_bucket_alloc_trans (2)

[syzbot] [bcachefs?] kernel BUG in bch2_bucket_alloc_trans (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    7234e2ea0edd Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1219f05f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7a3fccdd0bb995
dashboard link: https://syzkaller.appspot.com/bug?extid=2b6a17991a6af64f9489
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14018440580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14eb1087980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb89ee889cea/disk-7234e2ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/088257a81962/vmlinux-7234e2ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2a15a9a5e99a/bzImage-7234e2ea.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2ea41a6e1171/mount_0.gz

The issue was bisected to:

commit f5095b9f85a1674a92d00e7ab466499a8ba49ce1
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date:   Tue Jan 2 00:42:37 2024 +0000

    bcachefs: dev_usage updated by new accounting

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10b37fd0580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=12b37fd0580000
console output: https://syzkaller.appspot.com/x/log.txt?x=14b37fd0580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b6a17991a6af64f9489@syzkaller.appspotmail.com
Fixes: f5095b9f85a1 ("bcachefs: dev_usage updated by new accounting")

bcachefs (loop0): going read-only
bcachefs (loop0): finished waiting for writes to stop
bcachefs (loop0): flushing journal and stopping allocators, journal seq 1
------------[ cut here ]------------
kernel BUG at fs/bcachefs/alloc_foreground.c:489!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5220 Comm: syz-executor172 Not tainted 6.12.0-rc2-syzkaller-00305-g7234e2ea0edd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:489 [inline]
RIP: 0010:bch2_bucket_alloc_trans+0x39ec/0x3a50 fs/bcachefs/alloc_foreground.c:644
Code: e8 29 8a f0 fd e9 f0 c7 ff ff 89 d9 80 e1 07 38 c1 0f 8c f3 fd ff ff 48 89 df e8 bf 88 f0 fd e9 e6 fd ff ff e8 35 fc 89 fd 90 <0f> 0b e8 2d fc 89 fd 90 0f 0b e8 95 2b b2 07 f3 0f 1e fa e8 1c fc
RSP: 0018:ffffc90003e851c0 EFLAGS: 00010293
RAX: ffffffff840aeacb RBX: 0000000000000019 RCX: ffff88802d549e00
RDX: 0000000000000000 RSI: 0000000000000019 RDI: 0000000000000000
RBP: ffffc90003e858e8 R08: ffffffff840abd99 R09: 0000000000000000
R10: ffffc90003e857a8 R11: fffff520007d0afa R12: dffffc0000000000
R13: ffff88807a51c000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055555a922380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564dd46df160 CR3: 00000000766a2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_bucket_alloc_set_trans+0x517/0xd30 fs/bcachefs/alloc_foreground.c:804
 __open_bucket_add_buckets+0x10dc/0x1b60 fs/bcachefs/alloc_foreground.c:1049
 open_bucket_add_buckets+0x33a/0x410 fs/bcachefs/alloc_foreground.c:1093
 bch2_alloc_sectors_start_trans+0xce9/0x2030
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:343 [inline]
 bch2_btree_reserve_get+0x612/0x1890 fs/bcachefs/btree_update_interior.c:554
 bch2_btree_update_start+0xe56/0x14e0 fs/bcachefs/btree_update_interior.c:1252
 bch2_btree_split_leaf+0x123/0x840 fs/bcachefs/btree_update_interior.c:1850
 bch2_trans_commit_error+0x212/0x1390 fs/bcachefs/btree_trans_commit.c:942
 __bch2_trans_commit+0x7ead/0x93c0 fs/bcachefs/btree_trans_commit.c:1140
 wb_flush_one fs/bcachefs/btree_write_buffer.c:183 [inline]
 bch2_btree_write_buffer_flush_locked+0x2aa8/0x59f0 fs/bcachefs/btree_write_buffer.c:375
 btree_write_buffer_flush_seq+0x1a43/0x1bc0 fs/bcachefs/btree_write_buffer.c:510
 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525
 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565
 journal_flush_done+0x8e/0x260 fs/bcachefs/journal_reclaim.c:819
 bch2_journal_flush_pins+0x225/0x3a0 fs/bcachefs/journal_reclaim.c:852
 bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
 __bch2_fs_read_only+0x124/0x430 fs/bcachefs/super.c:274
 bch2_fs_read_only+0xb57/0x1200 fs/bcachefs/super.c:354
 __bch2_fs_stop+0x105/0x540 fs/bcachefs/super.c:619
 bch2_fs_stop+0x15/0x20 fs/bcachefs/super.c:678
 bch2_fs_get_tree+0xd9f/0x1710 fs/bcachefs/fs.c:2173
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f61de613dea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb66b7d48 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdb66b7d60 RCX: 00007f61de613dea
RDX: 0000000020005b00 RSI: 0000000020005b40 RDI: 00007ffdb66b7d60
RBP: 0000000000000004 R08: 00007ffdb66b7da0 R09: 0000000000005b42
R10: 0000000000000002 R11: 0000000000000282 R12: 0000000000000002
R13: 00007ffdb66b7da0 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:489 [inline]
RIP: 0010:bch2_bucket_alloc_trans+0x39ec/0x3a50 fs/bcachefs/alloc_foreground.c:644
Code: e8 29 8a f0 fd e9 f0 c7 ff ff 89 d9 80 e1 07 38 c1 0f 8c f3 fd ff ff 48 89 df e8 bf 88 f0 fd e9 e6 fd ff ff e8 35 fc 89 fd 90 <0f> 0b e8 2d fc 89 fd 90 0f 0b e8 95 2b b2 07 f3 0f 1e fa e8 1c fc
RSP: 0018:ffffc90003e851c0 EFLAGS: 00010293
RAX: ffffffff840aeacb RBX: 0000000000000019 RCX: ffff88802d549e00
RDX: 0000000000000000 RSI: 0000000000000019 RDI: 0000000000000000
RBP: ffffc90003e858e8 R08: ffffffff840abd99 R09: 0000000000000000
R10: ffffc90003e857a8 R11: fffff520007d0afa R12: dffffc0000000000
R13: ffff88807a51c000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055555a922380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564dd46df160 CR3: 00000000766a2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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(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

Re: [syzbot] [bcachefs?] kernel BUG in bch2_bucket_alloc_trans (2)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in bch2_journal_reclaim_thread

INFO: task bch-reclaim/loo:6038 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-reclaim/loo state:D stack:28984 pid:6038  tgid:6038  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
2 locks held by kworker/u8:5/999:
 #0: ffff8880b863ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593
 #1: ffffe8ffffc1c5c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x17c/0x7a0 kernel/sched/psi.c:937
2 locks held by kworker/u8:9/3035:
2 locks held by getty/4974:
 #0: ffff88802efa60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
7 locks held by syz.0.15/6010:
1 lock held by bch-reclaim/loo/6038:
 #0: ffff8880657cb0a8 (&j->reclaim_lock){+.+.}-{3:3}, at: bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3035 Comm: kworker/u8:9 Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:filter_irq_stacks+0x4f/0xa0 kernel/stacktrace.c:397
Code: 90 e4 c7 8b 48 89 fb eb 0c 49 ff c7 48 83 c3 08 4d 39 fc 74 4f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 97 d6 7a 00 4b 8b 04 fe 48 39 e8 72 0c 48 c7 c1
RSP: 0018:ffffc9000a16e9e8 EFLAGS: 00000246
RAX: 1ffff9200142dd60 RBX: ffffc9000a16eb00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000011 RDI: ffffc9000a16ea80
RBP: ffffffff8be00230 R08: 000000000000001b R09: ffffc9000a16e9f0
R10: ffffc9000a16e950 R11: ffffffff8180a090 R12: 0000000000000011
R13: ffffffff8bc7e490 R14: ffffc9000a16ea80 R15: 0000000000000010
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557255b808 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 stack_depot_save_flags+0x29/0x830 lib/stackdepot.c:609
 kasan_save_stack+0x4f/0x60 mm/kasan/common.c:48
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 kvfree_call_rcu+0xfc/0x790 kernel/rcu/tree.c:3810
 cfg80211_update_known_bss+0xb45/0x1590 net/wireless/scan.c:1891
 __cfg80211_bss_update+0x153/0x2030 net/wireless/scan.c:1938
 cfg80211_inform_single_bss_data+0xd82/0x2090 net/wireless/scan.c:2329
 cfg80211_inform_bss_data+0x3ce/0x5e70 net/wireless/scan.c:3184
 cfg80211_inform_bss_frame_data+0x3b8/0x720 net/wireless/scan.c:3279
 ieee80211_bss_info_update+0x8a7/0xbc0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info net/mac80211/ibss.c:1100 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1579 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1962/0x2d70 net/mac80211/ibss.c:1606
 ieee80211_iface_process_skb net/mac80211/iface.c:1603 [inline]
 ieee80211_iface_work+0x8a5/0xf20 net/mac80211/iface.c:1657
 cfg80211_wiphy_work+0x2db/0x490 net/wireless/core.c:440
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>


Tested on:

commit:         715ca9dd Merge tag 'io_uring-6.12-20241019' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15b4425f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=78db40d8379956d9
dashboard link: https://syzkaller.appspot.com/bug?extid=2b6a17991a6af64f9489
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16b8425f980000

Re: [syzbot] [bcachefs?] kernel BUG in bch2_bucket_alloc_trans (2)

[syzbot]

Hello,

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

Reported-by: syzbot+2b6a17991a6af64f9489@syzkaller.appspotmail.com
Tested-by: syzbot+2b6a17991a6af64f9489@syzkaller.appspotmail.com

Tested on:

commit:         715ca9dd Merge tag 'io_uring-6.12-20241019' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15d38c87980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=78db40d8379956d9
dashboard link: https://syzkaller.appspot.com/bug?extid=2b6a17991a6af64f9489
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1431a0a7980000

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

Re: [syzbot] [bcachefs?] kernel BUG in bch2_bucket_alloc_trans (2)

[syzbot]

Hello,

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

Reported-by: syzbot+2b6a17991a6af64f9489@syzkaller.appspotmail.com
Tested-by: syzbot+2b6a17991a6af64f9489@syzkaller.appspotmail.com

Tested on:

commit:         42f7652d Linux 6.12-rc4
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13bc6a40580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41330fd2db03893d
dashboard link: https://syzkaller.appspot.com/bug?extid=2b6a17991a6af64f9489
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16d46a40580000

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