syzbot


INFO: rcu detected stall in sys_readlink (5)

Status: upstream: reported syz repro on 2024/10/18 11:28
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+23e14ec82f3c8692eaa9@syzkaller.appspotmail.com
First crash: 168d, last: 20d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fs?] INFO: rcu detected stall in sys_readlink (5) 0 (1) 2024/10/18 11:28
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_readlink (2) kernel 3 694d 753d 0/28 auto-obsoleted due to no activity on 2023/04/24 08:02
linux-5.15 INFO: rcu detected stall in sys_readlink 1 463d 463d 0/3 auto-obsoleted due to no activity on 2023/12/08 09:32
upstream INFO: rcu detected stall in sys_readlink fs 1 957d 957d 0/28 auto-closed as invalid on 2022/07/22 05:22
linux-5.15 INFO: rcu detected stall in sys_readlink (2) 3 128d 153d 0/3 auto-obsoleted due to no activity on 2024/11/07 23:07
upstream INFO: rcu detected stall in sys_readlink (4) fs 2 368d 371d 0/28 auto-obsoleted due to no activity on 2024/03/02 18:22
linux-6.1 INFO: rcu detected stall in sys_readlink 3 35d 127d 0/3 upstream: reported on 2024/07/31 14:16
upstream INFO: rcu detected stall in sys_readlink (3) bpf fs 2 569d 576d 0/28 auto-obsoleted due to no activity on 2023/08/14 04:05
android-5-15 BUG: soft lockup in sys_readlink 2 178d 237d 0/2 auto-obsoleted due to no activity on 2024/09/08 11:06
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/11/13 05:15 17m retest repro https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing OK log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9640/1:b..l P5208/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=23737, q=353 ncpus=2)
task:udevd           state:R  running task     stack:21664 pid:5208  tgid:5208  ppid:1      flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6693
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7015
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:mnt_idmap include/linux/mount.h:79 [inline]
RIP: 0010:link_path_walk+0x1a0/0xea0 fs/namei.c:2365
Code: 8b 84 24 90 00 00 00 42 80 3c 20 00 74 08 48 89 ef e8 04 36 e9 ff 48 8b 5d 00 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 e6 35 e9 ff 48 8b 03 48 89 44 24 78 48 8b 44 24
RSP: 0018:ffffc90004037ac0 EFLAGS: 00000246
RAX: 1ffff11003bd958f RBX: ffff88801decac78 RCX: ffff888044978000
RDX: 0000000000000002 RSI: ffffffff8ea7d210 RDI: 0000000000000072
RBP: ffffc90004037c60 R08: 0000000000000001 R09: ffffffff82158f96
R10: 0000000000000002 R11: ffff888044978000 R12: dffffc0000000000
R13: ffff88802f8fe621 R14: ffffc90004037c68 R15: ffffc90004037c98
 path_lookupat+0xa9/0x450 fs/namei.c:2579
 filename_lookup+0x256/0x610 fs/namei.c:2609
 do_readlinkat+0xf0/0x3a0 fs/stat.c:537
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x7f/0x90 fs/stat.c:571
 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: 0033:0x7f985e917d47
RSP: 002b:00007ffea1b65cc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffea1b664e8 RCX: 00007f985e917d47
RDX: 0000000000000200 RSI: 00007ffea1b65cd8 RDI: 00007ffea1b65ed8
RBP: 000055d600c46910 R08: 0000000000000000 R09: 00007ffea1b65648
R10: 00007f985ee850b8 R11: 0000000000000202 R12: 00007ffea1b65cd8
R13: 00007ffea1b65ed8 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:syz.1.1492      state:R  running task     stack:25920 pid:9640  tgid:9640  ppid:5839   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6693
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6872
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6896
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1691 [inline]
 zap_pmd_range mm/memory.c:1739 [inline]
 zap_pud_range mm/memory.c:1768 [inline]
 zap_p4d_range mm/memory.c:1789 [inline]
 unmap_page_range+0x36b1/0x40e0 mm/memory.c:1810
 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900
 exit_mmap+0x275/0xc40 mm/mmap.c:1923
 __mmput+0x115/0x390 kernel/fork.c:1348
 exit_mm+0x220/0x310 kernel/exit.c:571
 do_exit+0x9b2/0x28e0 kernel/exit.c:926
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 __do_sys_exit_group kernel/exit.c:1099 [inline]
 __se_sys_exit_group kernel/exit.c:1097 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097
 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
 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: 0033:0x7fca0257e719
RSP: 002b:00007fff3e7f2868 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fca0257e719
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff3e7f28bc R08: 00007fff3e7f294f R09: 000000000003774f
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032
R13: 000000000003774f R14: 00000000000376ce R15: 00007fff3e7f2910
 </TASK>
rcu: rcu_preempt kthread starved for 10568 jiffies! g23737 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:25232 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6693
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5909 Comm: kworker/0:8 Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:usb_hcd_submit_urb+0x370/0x1e80
Code: 03 42 80 3c 20 00 4c 8b 34 24 74 08 48 89 df e8 86 4a c6 fa 4c 8b 1b 4c 89 f7 48 8b 74 24 08 8b 54 24 20 e8 22 50 99 04 89 c3 <45> 31 f6 31 ff 89 c6 e8 44 72 5c fa 85 db 0f 85 d9 0f 00 00 e8 f7
RSP: 0018:ffffc90000007580 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000102
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffffc900000076f0 R08: ffff888145718003 R09: 1ffff11028ae3000
R10: dffffc0000000000 R11: ffffed1028ae3001 R12: dffffc0000000000
R13: 1ffff11028b61043 R14: ffff888145b08000 R15: ffff888145b08218
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c24f4fd CR3: 0000000031b4e000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 ath9k_hif_usb_rx_cb+0x11f7/0x1590 drivers/net/wireless/ath/ath9k/hif_usb.c:722
 __usb_hcd_giveback_urb+0x42e/0x6e0 drivers/usb/core/hcd.c:1650
 dummy_timer+0x856/0x4620 drivers/usb/gadget/udc/dummy_hcd.c:1993
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x59d/0xd50 kernel/time/hrtimer.c:1755
 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1772
 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_schedule_irq+0xf6/0x1c0 kernel/sched/core.c:7015
Code: 89 f5 49 c1 ed 03 eb 0d 48 f7 03 08 00 00 00 0f 84 8b 00 00 00 bf 01 00 00 00 e8 c5 42 93 f5 e8 50 b5 cc f5 fb bf 01 00 00 00 <e8> 85 ab ff ff 43 80 7c 3d 00 00 74 08 4c 89 f7 e8 a5 cb 2e f6 48
RSP: 0018:ffffc900043678e0 EFLAGS: 00000282
RAX: 47e92bc5f8f39f00 RBX: 1ffff9200086cf24 RCX: ffffffff8170cfaa
RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: 0000000000000001
RBP: ffffc900043679a0 R08: ffffffff942d0897 R09: 1ffffffff285a112
R10: dffffc0000000000 R11: fffffbfff285a113 R12: 1ffff9200086cf1c
R13: 1ffff9200086cf20 R14: ffffc90004367900 R15: dffffc0000000000
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:389
Code: 8c e8 14 69 70 0a 65 66 8b 05 24 4a ac 7e 66 85 c0 75 5d bf 01 00 00 00 e8 2d b2 0b 00 e8 18 23 45 00 fb 65 8b 05 e8 49 ac 7e <85> c0 75 05 e8 a7 28 a9 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc90004367a60 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 1ffff9200086cf50 RCX: ffffffff8170cfaa
RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: ffffffff8c610ce0
RBP: ffffc90004367b20 R08: ffffffff942d0897 R09: 1ffffffff285a112
R10: dffffc0000000000 R11: fffffbfff285a113 R12: dffffc0000000000
R13: 1ffff9200086cf54 R14: ffffc90004367aa0 R15: 0000000000000201
 neigh_periodic_work+0xb35/0xd50 net/core/neighbour.c:1019
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available
IPVS: ovf: UDP 224.0.0.2:0 - no destination available

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/15 08:02 upstream cfaaa7d010d1 f6ede3a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/10/22 14:19 upstream c2ee9f594da8 9d74f456 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/10/11 07:52 upstream 1d227fcc7222 cd942402 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/10/07 17:16 upstream 8cf0b93919e1 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_readlink
2024/09/18 06:24 upstream a430d95c5efa c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_readlink
2024/09/13 01:49 upstream 77f587896757 60e1a995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_readlink
2024/09/09 00:09 upstream 89f5e14d05b4 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_readlink
2024/09/07 18:21 upstream b31c44928842 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/07/27 19:15 upstream 3a7e02c040b1 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_readlink
2024/07/14 10:48 upstream d0d0cd380055 eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/07/08 22:54 upstream 256abd8e550c cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_readlink
2024/07/04 20:12 upstream 795c58e4c7fc dc6bbff0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/10/12 04:35 net 8a6be4bd6fb3 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_readlink
2024/10/19 03:55 net-next 6d858708d465 cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_readlink
2024/10/28 17:21 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c6d9e43954bf 9efb3cc7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/21 09:02 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c6d9e43954bf cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/17 01:02 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7b5a58952fc3 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/14 11:15 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 64f3b5a6bc49 084d8178 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/10 16:11 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 4a9fe2a8ac53 8fbfc0c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/08 03:59 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 4a9fe2a8ac53 402f1df0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/10/05 07:42 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 4a9fe2a8ac53 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
2024/07/21 12:32 linux-next 41c196e567fb b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_readlink
2024/06/20 09:28 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing b0fc24f36191 41b7e219 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_readlink
* Struck through repros no longer work on HEAD.