syzbot


INFO: rcu detected stall in sys_mkdirat

Status: upstream: reported on 2024/10/14 13:32
Reported-by: syzbot+005a4e31cafef8f9177a@syzkaller.appspotmail.com
First crash: 38d, last: 38d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in sys_mkdirat 1 380d 380d 0/3 auto-obsoleted due to no activity on 2024/02/15 18:20
upstream INFO: rcu detected stall in sys_mkdirat ext4 net 3 589d 705d 0/28 auto-obsoleted due to no activity on 2023/07/11 04:05
android-5-15 BUG: soft lockup in sys_mkdirat 8 168d 220d 0/2 auto-obsoleted due to no activity on 2024/09/03 20:00

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2662 jiffies s: 7109 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4486 Comm: syz.4.263 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4222 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4248 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x255/0x7a0 kernel/locking/lockdep.c:4315
Code: 8b 44 24 10 48 8d 98 e0 0a 00 00 4c 8d a0 00 0b 00 00 45 31 ed 49 83 fd 31 0f 83 a5 00 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 10 <84> c0 75 54 8b 43 20 a9 00 00 04 00 74 2c 31 d2 a9 00 00 03 00 0f
RSP: 0018:ffffc90000007940 EFLAGS: 00000806
RAX: 0000000000000000 RBX: ffff8880264628c8 RCX: ffffffff816af0fa
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff911dd2e8
RBP: ffffc90000007a00 R08: dffffc0000000000 R09: fffffbfff223ba5e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880264628e8
R13: 0000000000000001 R14: ffff888026462898 R15: 1ffff11004c8c513
FS:  00007f61fdc146c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe12cca1690 CR3: 0000000063ef6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:rcu_read_unlock_special+0x84/0x540 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 49 89 04 17 66 41 c7 44 17 09 f3 f3 41 c6 44 17 0b f3 65 44 8b 25 2d 37 8e 7e 41 f7 c4 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 3a 00 00 00 00 66 42 c7 44 3a
RSP: 0018:ffffc90000007ac0 EFLAGS: 00000206
RAX: 88aa7b8a93211e00 RBX: 1ffff92000000f60 RCX: ffffffff816af0fa
RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: ffffffff8b5d7180
RBP: ffffc90000007ba0 R08: dffffc0000000000 R09: fffffbfff223ba45
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8d32fe00
R13: ffff888026462218 R14: ffffc90000007b00 R15: 1ffff92000000f5c
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x153/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xd0/0x1e0 drivers/net/wireless/mac80211_hwsim.c:2142
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1753
 hrtimer_run_softirq+0x196/0x2c0 kernel/time/hrtimer.c:1770
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 __do_softirq kernel/softirq.c:605 [inline]
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__kernfs_create_file+0x56/0x2e0
Code: 48 89 ef 4c 89 ee 89 da 44 89 e1 45 89 f0 41 b9 02 00 00 00 e8 5b 4a ff ff 48 85 c0 0f 84 e6 00 00 00 49 89 c4 4c 8b 74 24 38 <49> bd 00 00 00 00 00 fc ff df 48 8d 78 68 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc9000445f7c8 EFLAGS: 00000282
RAX: ffff888062d1d9f8 RBX: 0000000000008124 RCX: ffffffff82193279
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801f3192b8
RBP: ffff88801f3192b8 R08: dffffc0000000000 R09: ffffed1003e63258
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888062d1d9f8
R13: ffffc9000445f9e0 R14: ffffffff8d358480 R15: 0000000000000000
 cgroup_add_file kernel/cgroup/cgroup.c:4205 [inline]
 cgroup_addrm_files+0xaae/0x1030 kernel/cgroup/cgroup.c:4265
 css_populate_dir+0x12d/0x360 kernel/cgroup/cgroup.c:1771
 cgroup_apply_control_enable+0x61b/0xae0 kernel/cgroup/cgroup.c:3267
 cgroup_mkdir+0xd8b/0xff0 kernel/cgroup/cgroup.c:5767
 kernfs_iop_mkdir+0x275/0x400 fs/kernfs/dir.c:1221
 vfs_mkdir+0x3b6/0x590 fs/namei.c:4108
 do_mkdirat+0x225/0x360 fs/namei.c:4133
 __do_sys_mkdirat fs/namei.c:4148 [inline]
 __se_sys_mkdirat fs/namei.c:4146 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4146
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f61fcd7dff9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f61fdc14038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f61fcf35f80 RCX: 00007f61fcd7dff9
RDX: 00000000000001ff RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 00007f61fcdf0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f61fcf35f80 R15: 00007ffdfc676a28
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/14 13:32 linux-6.1.y aa4cd140bba5 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_mkdirat
* Struck through repros no longer work on HEAD.