On May 20, 2024, at 15:12, syzbot <[email protected]> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 8c06da67d0bd Merge tag 'livepatching-for-6.10' of git://gi.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11e74ef4980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cc69cd6a2dcb5aa > dashboard link: https://syzkaller.appspot.com/bug?extid=a6060114362257e9798a > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) > 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: > https://storage.googleapis.com/syzbot-assets/331202aeac12/disk-8c06da67.raw.xz > vmlinux: > https://storage.googleapis.com/syzbot-assets/4db56871f364/vmlinux-8c06da67.xz > kernel image: > https://storage.googleapis.com/syzbot-assets/2ab7bc870390/bzImage-8c06da67.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: [email protected] > > INFO: task syz-executor.4:6256 blocked for more than 143 seconds. > Not tainted 6.9.0-syzkaller-07387-g8c06da67d0bd #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor.4 state:D stack:14936 pid:6256 tgid:6255 ppid:5481 > flags:0x00004006 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:5409 [inline] > __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 > __schedule_loop kernel/sched/core.c:6823 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6838 > __bch2_two_state_lock+0x171/0x200 fs/bcachefs/two_state_shared_lock.c:7 > bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:56 [inline] > bch2_readahead+0xcf5/0x1870 fs/bcachefs/fs-io-buffered.c:277 > read_pages+0x17e/0x840 mm/readahead.c:160 > page_cache_ra_order+0xa62/0xcc0 mm/readahead.c:531 > filemap_readahead mm/filemap.c:2480 [inline] > filemap_get_pages+0x743/0x2090 mm/filemap.c:2521 > filemap_splice_read+0x654/0xeb0 mm/filemap.c:2870 > do_splice_read fs/splice.c:985 [inline] > splice_direct_to_actor+0x4b7/0xc90 fs/splice.c:1089 > do_splice_direct_actor fs/splice.c:1207 [inline] > do_splice_direct+0x28c/0x3e0 fs/splice.c:1233 > do_sendfile+0x56d/0xdc0 fs/read_write.c:1295 > __do_sys_sendfile64 fs/read_write.c:1362 [inline] > __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f8ff447cee9 > RSP: 002b:00007f8ff52d30c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 > RAX: ffffffffffffffda RBX: 00007f8ff45abf80 RCX: 00007f8ff447cee9 > RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000006 > RBP: 00007f8ff44c949e R08: 0000000000000000 R09: 0000000000000000 > R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 > R13: 000000000000000b R14: 00007f8ff45abf80 R15: 00007ffe62ab44e8 > </TASK> > INFO: task syz-executor.4:6292 blocked for more than 144 seconds. > Not tainted 6.9.0-syzkaller-07387-g8c06da67d0bd #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor.4 state:D > stack:18064 pid:6292 tgid:6255 ppid:5481 flags:0x00004006 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:5409 [inline] > __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 > __schedule_loop kernel/sched/core.c:6823 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6838 > io_schedule+0x8d/0x110 kernel/sched/core.c:9044 > folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1283 > bch2_seek_pagecache_data+0x2c6/0xac0 fs/bcachefs/fs-io-pagecache.c:690 > bch2_clamp_data_hole+0x121/0x180 fs/bcachefs/fs-io-pagecache.c:793 > __bchfs_fallocate fs/bcachefs/fs-io.c:647 [inline] > bchfs_fallocate fs/bcachefs/fs-io.c:733 [inline] > bch2_fallocate_dispatch+0x1a84/0x3810 fs/bcachefs/fs-io.c:780 > vfs_fallocate+0x564/0x6c0 fs/open.c:330 > ksys_fallocate fs/open.c:353 [inline] > __do_sys_fallocate fs/open.c:361 [inline] > __se_sys_fallocate fs/open.c:359 [inline] > __x64_sys_fallocate+0xbd/0x110 fs/open.c:359 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f8ff447cee9 > RSP: 002b:00007f8ff52b20c8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d > RAX: ffffffffffffffda RBX: 00007f8ff45ac050 RCX: 00007f8ff447cee9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 > RBP: 00007f8ff44c949e R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000001000f4 R11: 0000000000000246 R12: 0000000000000000 > R13: 000000000000006e R14: 00007f8ff45ac050 R15: 00007ffe62ab44e8 > </TASK> > INFO: task syz-executor.4:6293 blocked for more than 144 seconds. > Not tainted 6.9.0-syzkaller-07387-g8c06da67d0bd #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor.4 state:D stack:28656 pid:6293 tgid:6255 ppid:5481 > flags:0x00000006 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:5409 [inline] > __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 > __schedule_loop kernel/sched/core.c:6823 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6838 > __bch2_two_state_lock+0x171/0x200 fs/bcachefs/two_state_shared_lock.c:7 > bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:56 [inline] > bch2_buffered_write fs/bcachefs/fs-io-buffered.c:1045 [inline] > bch2_write_iter+0x410/0x2840 fs/bcachefs/fs-io-buffered.c:1144 > call_write_iter include/linux/fs.h:2120 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa2d/0xc50 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f8ff447cee9 > RSP: 002b:00007f8ff52910c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007f8ff45ac120 RCX: 00007f8ff447cee9 > RDX: 0000000000000009 RSI: 0000000020000040 RDI: 0000000000000004 > RBP: 00007f8ff44c949e R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 000000000000006e R14: 00007f8ff45ac120 R15: 00007ffe62ab44e8 > </TASK> > > Showing all locks held in the system: > 1 lock held by khungtaskd/30: > #0: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire > include/linux/rcupdate.h:329 [inline] > #0: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock > include/linux/rcupdate.h:781 [inline] > #0: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: > debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 > 4 locks held by kworker/u8:9/2838: > #0: ffff888015ed3148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work > kernel/workqueue.c:3242 [inline] > #0: ffff888015ed3148 ((wq_completion)netns){+.+.}-{0:0}, at: > process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 > #1: ffffc9000a487d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work > kernel/workqueue.c:3243 [inline] > #1: ffffc9000a487d00 (net_cleanup_work){+.+.}-{0:0}, at: > process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 > #2: ffffffff8f5c1a10 (pernet_ops_rwsem){++++}-{3:3}, at: > cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594 > #3: ffffffff8f5ce3c8 (rtnl_mutex){+.+.}-{3:3}, at: > default_device_exit_batch+0xe9/0xa90 net/core/dev.c:11745 > 2 locks held by dhcpcd/4752: > #0: ffff888061cc6678 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: > __netlink_dump_start+0x119/0x780 net/netlink/af_netlink.c:2418 > #1: ffffffff8f5ce3c8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x5d3/0xe50 > net/netlink/af_netlink.c:2336 > 2 locks held by getty/4839: > #0: ffff8880785280a0 (&tty->ldisc_sem){++++}-{0:0}, at: > tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 > #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: > n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 > 2 locks held by syz-executor.4/6256: > #0: ffff88805683be30 (mapping.invalidate_lock#4){.+.+}-{3:3}, at: > filemap_invalidate_lock_shared include/linux/fs.h:846 [inline] > #0: ffff88805683be30 (mapping.invalidate_lock#4){.+.+}-{3:3}, at: > page_cache_ra_order+0x3bc/0xcc0 mm/readahead.c:510 > #1: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > srcu_lock_acquire include/linux/srcu.h:116 [inline] > #1: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > srcu_read_lock include/linux/srcu.h:215 [inline] > #1: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > __bch2_trans_get+0x911/0xd30 fs/bcachefs/btree_iter.c:3069 > 3 locks held by syz-executor.4/6292: > #0: ffff8880242c2420 (sb_writers#14){.+.+}-{0:0}, at: file_start_write > include/linux/fs.h:2871 [inline] > #0: ffff8880242c2420 (sb_writers#14){.+.+}-{0:0}, at: > vfs_fallocate+0x4d3/0x6c0 fs/open.c:329 > #1: ffff88805683bc90 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: > inode_lock include/linux/fs.h:791 [inline] > #1: ffff88805683bc90 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: > bch2_fallocate_dispatch+0x295/0x3810 fs/bcachefs/fs-io.c:771 > #2: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > srcu_lock_acquire include/linux/srcu.h:116 [inline] > #2: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > srcu_read_lock include/linux/srcu.h:215 [inline] > #2: ffff888050b84250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > bch2_trans_srcu_lock+0xb1/0x220 fs/bcachefs/btree_iter.c:2896 > 2 locks held by syz-executor.4/6293: > #0: ffff8880246754c8 (&f->f_pos_lock){+.+.}-{3:3}, at: > __fdget_pos+0x259/0x320 fs/file.c:1191 > #1: ffff8880242c2420 (sb_writers#14){.+.+}-{0:0}, at: file_start_write > include/linux/fs.h:2871 [inline] > #1: ffff8880242c2420 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x227/0xc50 > fs/read_write.c:586 > 1 lock held by syz-executor.1/8207: > #0: ffffffff8e33b5b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock > kernel/rcu/tree_exp.h:323 [inline] > #0: ffffffff8e33b5b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: > synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:939 > 1 lock held by syz-executor.0/8583: > #0: ffffffff8f5ce3c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock > net/core/rtnetlink.c:79 [inline] > #0: ffffffff8f5ce3c8 (rtnl_mutex){+.+.}-{3:3}, at: __rtnl_newlink > net/core/rtnetlink.c:3720 [inline] > #0: ffffffff8f5ce3c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_newlink+0xab5/0x20a0 > net/core/rtnetlink.c:3743 > 5 locks held by syz-executor.3/8673: > 2 locks held by syz-executor.4/8675: > > ============================================= > > NMI backtrace for cpu 0 > CPU: 0 PID: 30 Comm: khungtaskd Not tainted > 6.9.0-syzkaller-07387-g8c06da67d0bd #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 04/02/2024 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 > 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:160 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] > watchdog+0xfde/0x1020 kernel/hung_task.c:380 > 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 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 PID: 8673 Comm: syz-executor.3 Not tainted > 6.9.0-syzkaller-07387-g8c06da67d0bd #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 04/02/2024 > RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 > [inline] > RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:724 > Code: e8 4b 7c 02 0a 89 c3 83 f8 08 73 7a 49 bf 00 00 00 00 00 fc ff df 4c 8d > 34 dd 20 7a d9 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 ac > 73 7b 00 48 c7 c3 08 7d 03 00 49 03 1e 48 89 > RSP: 0018:ffffc9000306f600 EFLAGS: 00000246 > RAX: 1ffffffff1bb2f45 RBX: 0000000000000001 RCX: ffffffff8172f1b0 > RDX: 0000000000000000 RSI: ffffffff8c1edc40 RDI: ffffffff8c1edc00 > RBP: ffffc9000306f758 R08: ffffffff8fabae2f R09: 1ffffffff1f575c5 > R10: dffffc0000000000 R11: fffffbfff1f575c6 R12: 1ffff9200060ded0 > R13: ffffffff82010bf4 R14: ffffffff8dd97a28 R15: dffffc0000000000 > FS: 00007f9c691596c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055558e530978 CR3: 000000002931c000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <NMI> > </NMI> > <TASK> > trace_lock_release include/trace/events/lock.h:69 [inline] > lock_release+0xbf/0x9f0 kernel/locking/lockdep.c:5765 > rcu_lock_release include/linux/rcupdate.h:339 [inline] > rcu_read_unlock include/linux/rcupdate.h:812 [inline] > percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline] > percpu_ref_tryget+0xf7/0x180 include/linux/percpu-refcount.h:266 > css_tryget include/linux/cgroup_refcnt.h:45 [inline] > get_mem_cgroup_from_mm+0x103/0x2a0 mm/memcontrol.c:1112 > __mem_cgroup_charge+0x16/0x80 mm/memcontrol.c:7298 > mem_cgroup_charge include/linux/memcontrol.h:691 [inline] > shmem_alloc_and_add_folio+0x456/0xbc0 mm/shmem.c:1677 > shmem_get_folio_gfp+0x82d/0x1f50 mm/shmem.c:2055 > shmem_get_folio mm/shmem.c:2160 [inline] > shmem_write_begin+0x170/0x4d0 mm/shmem.c:2744 > generic_perform_write+0x322/0x640 mm/filemap.c:3974 > shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2920 > call_write_iter include/linux/fs.h:2120 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa2d/0xc50 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f9c6847bc2f > Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 > 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 > 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48 > RSP: 002b:00007f9c69158e80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007f9c6847bc2f > RDX: 00000000013bd7ef RSI: 00007f9c5e200000 RDI: 0000000000000005 > RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000551e > R10: 00000000000003c8 R11: 0000000000000293 R12: 0000000000000005 > R13: 00007f9c69158f80 R14: 00007f9c69158f40 R15: 00007f9c5e200000 > </TASK> > > > --- > 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 [email protected]. > > 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 >
#syz fix: bcachefs: Fix readahead involved deadlock
