BUG: soft lockup in sys_readlink

Status: auto-obsoleted due to no activity on 2024/09/08 11:06
Reported-by: syzbot+382bb43215df2d327c00@syzkaller.appspotmail.com
First crash: 839d, last: 781d
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_readlink (2) kernel 1 3 1296d 1356d 0/29 auto-obsoleted due to no activity on 2023/04/24 08:02
linux-5.15 INFO: rcu detected stall in sys_readlink (4) 1 4 215d 297d 0/3 auto-obsoleted due to no activity on 2026/04/06 17:59
linux-5.15 INFO: rcu detected stall in sys_readlink 1 1 1066d 1066d 0/3 auto-obsoleted due to no activity on 2023/12/08 09:32
upstream INFO: rcu detected stall in sys_readlink fs 1 1 1560d 1560d 0/29 auto-closed as invalid on 2022/07/22 05:22
linux-5.15 INFO: rcu detected stall in sys_readlink (2) 1 3 730d 755d 0/3 auto-obsoleted due to no activity on 2024/11/07 23:07
upstream INFO: rcu detected stall in sys_readlink (4) fs 1 2 970d 974d 0/29 auto-obsoleted due to no activity on 2024/03/02 18:22
linux-6.1 INFO: rcu detected stall in sys_readlink (2) 1 2 378d 406d 0/3 auto-obsoleted due to no activity on 2025/10/26 06:03
linux-6.1 INFO: rcu detected stall in sys_readlink 1 4 539d 729d 0/3 auto-obsoleted due to no activity on 2025/05/18 03:23
upstream INFO: rcu detected stall in sys_readlink (3) fs bpf 1 2 1172d 1178d 0/29 auto-obsoleted due to no activity on 2023/08/14 04:05
upstream INFO: rcu detected stall in sys_readlink (5) prio:normal kernfs 1 syz done error 55 13d 651d 0/29 upstream: reported syz repro on 2024/10/18 11:28
linux-6.6 INFO: rcu detected stall in sys_readlink 1 4 106d 243d 0/2 auto-obsoleted due to no activity on 2026/07/25 05:40
linux-5.15 INFO: rcu detected stall in sys_readlink (3) 1 3 401d 534d 0/3 auto-obsoleted due to no activity on 2025/10/02 16:41

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [syz-executor.4:1390]
Modules linked in:
CPU: 0 PID: 1390 Comm: syz-executor.4 Not tainted 5.15.149-syzkaller-00131-g79bd336c7a94 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:918
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d cb 03 f3 03 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0018:ffffc90001135f80 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 1ffff92000226bf4 RCX: ffffffff8154fa3f
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff888116e92c58
RBP: ffffc90001136030 R08: dffffc0000000000 R09: ffffed1022dd258c
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888116e92c58 R14: 0000000000000003 R15: 1ffff92000226bf8
FS:  00007f567371a6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffde000000 CR3: 000000012d383000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6bc/0xc40 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:178
 sock_hash_delete_elem+0xb1/0x2f0 net/core/sock_map.c:937
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xfb0
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
 bpf_trace_run4+0x13f/0x270 kernel/trace/bpf_trace.c:1919
 __bpf_trace_mm_page_alloc+0xbf/0xf0 include/trace/events/kmem.h:201
 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline]
 __alloc_pages+0x3cb/0x8f0 mm/page_alloc.c:5798
 __alloc_pages_node include/linux/gfp.h:591 [inline]
 alloc_pages_node include/linux/gfp.h:605 [inline]
 alloc_pages include/linux/gfp.h:618 [inline]
 __stack_depot_save+0x38d/0x470 lib/stackdepot.c:326
 kasan_save_stack mm/kasan/common.c:39 [inline]
 kasan_set_track+0x5d/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xbd/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3519 [inline]
 kfree+0xc8/0x220 mm/slub.c:4579
 sk_psock_free_link include/linux/skmsg.h:420 [inline]
 sock_map_del_link net/core/sock_map.c:160 [inline]
 sock_map_unref+0x352/0x4d0 net/core/sock_map.c:182
 sock_hash_delete_elem+0x274/0x2f0 net/core/sock_map.c:941
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xfb0
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
 bpf_trace_run4+0x13f/0x270 kernel/trace/bpf_trace.c:1919
 __bpf_trace_mm_page_alloc+0xbf/0xf0 include/trace/events/kmem.h:201
 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline]
 __alloc_pages+0x3cb/0x8f0 mm/page_alloc.c:5798
 __alloc_pages_node include/linux/gfp.h:591 [inline]
 alloc_pages_node include/linux/gfp.h:605 [inline]
 alloc_pages include/linux/gfp.h:618 [inline]
 __stack_depot_save+0x38d/0x470 lib/stackdepot.c:326
 stack_depot_save+0xe/0x10 lib/stackdepot.c:383
 save_stack+0x104/0x1e0 mm/page_owner.c:140
 __set_page_owner+0x28/0x2e0 mm/page_owner.c:200
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2604
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2610
 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4484
 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5776
 __alloc_pages_node include/linux/gfp.h:591 [inline]
 alloc_pages_node include/linux/gfp.h:605 [inline]
 alloc_pages include/linux/gfp.h:618 [inline]
 __stack_depot_save+0x38d/0x470 lib/stackdepot.c:326
 kasan_save_stack mm/kasan/common.c:39 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 ____kasan_kmalloc+0xed/0x110 mm/kasan/common.c:512
 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 kmem_cache_alloc_trace+0x115/0x210 mm/slub.c:3267
 kmalloc include/linux/slab.h:603 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 fuse_dentry_init+0x4f/0x90 fs/fuse/dir.c:353
 __d_alloc+0x49a/0x6c0 fs/dcache.c:1799
 d_alloc fs/dcache.c:1824 [inline]
 d_alloc_parallel+0xe6/0x12e0 fs/dcache.c:2576
 __lookup_slow+0x154/0x400 fs/namei.c:1648
 lookup_slow+0x5a/0x80 fs/namei.c:1680
 walk_component+0x48c/0x610 fs/namei.c:1976
 link_path_walk+0x642/0xd90
 path_lookupat+0xa0/0x450 fs/namei.c:2454
 filename_lookup+0x230/0x5c0 fs/namei.c:2484
 user_path_at_empty+0x43/0x1a0 fs/namei.c:2883
 do_readlinkat+0x114/0x3a0 fs/stat.c:442
 __do_sys_readlink fs/stat.c:475 [inline]
 __se_sys_readlink fs/stat.c:472 [inline]
 __x64_sys_readlink+0x7f/0x90 fs/stat.c:472
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f567439ff69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f567371a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007f56744d6f80 RCX: 00007f567439ff69
RDX: 00000000000000a7 RSI: 0000000020000080 RDI: 0000000020000040
RBP: 00007f56743fd6fe R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f56744d6f80 R15: 00007ffc3e4d1a08
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1388 Comm: syz-executor.1 Not tainted 5.15.149-syzkaller-00131-g79bd336c7a94 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x147/0x180 arch/x86/kernel/kvm.c:918
Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 44 8b 74 24 1c 75 34 41 0f b6 45 00 44 38 f0 75 10 66 90 0f 00 2d cb 03 f3 03 fb f4 <e9> 24 ff ff ff fb e9 1e ff ff ff 44 89 e9 80 e1 07 38 c1 7c a3 4c
RSP: 0000:ffffc9000128f300 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff92000251e64 RCX: 1ffffffff0d1aa9c
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8881f7138ad4
RBP: ffffc9000128f3b0 R08: dffffc0000000000 R09: ffffed103ee2715b
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f7138ad4 R14: 0000000000000001 R15: 1ffff92000251e68
FS:  00007fa2c9c5d6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa2c2a00000 CR3: 0000000116c5c000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline]
 __pv_queued_spin_lock_slowpath+0x41b/0xc40 kernel/locking/qspinlock.c:473
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:178
 sock_hash_delete_elem+0xb1/0x2f0 net/core/sock_map.c:937
 bpf_prog_2c29ac5cdc6b1842+0x3a/0xfb0
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
 bpf_trace_run4+0x13f/0x270 kernel/trace/bpf_trace.c:1919
 __bpf_trace_mm_page_alloc+0xbf/0xf0 include/trace/events/kmem.h:201
 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline]
 __alloc_pages+0x3cb/0x8f0 mm/page_alloc.c:5798
 __alloc_pages_node include/linux/gfp.h:591 [inline]
 alloc_pages_node include/linux/gfp.h:605 [inline]
 alloc_pages include/linux/gfp.h:618 [inline]
 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline]
 pte_alloc_one+0x73/0x1b0 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x86/0x350 mm/memory.c:499
 do_anonymous_page mm/memory.c:4009 [inline]
 handle_pte_fault+0x1fb7/0x24d0 mm/memory.c:4869
 do_handle_mm_fault+0x1ea9/0x23a0 mm/memory.c:5293
 handle_mm_fault include/linux/mm.h:1836 [inline]
 do_user_addr_fault arch/x86/mm/fault.c:1458 [inline]
 handle_page_fault arch/x86/mm/fault.c:1549 [inline]
 exc_page_fault+0x3b5/0x830 arch/x86/mm/fault.c:1605
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0033:0x7fa2ca8d09f6
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007fa2c9c5c530 EFLAGS: 00010206
RAX: 00000000011c3001 RBX: 00007fa2c9c5c5d0 RCX: 000000000000000a
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fa2c9c5c670
RBP: 0000000000000102 R08: 00007fa2c183d000 R09: 00000000011c3000
R10: 0000000000000000 R11: 00007fa2c9c5c5e0 R12: 0000000000000001
R13: 00007fa2ca993fa0 R14: 0000000000000000 R15: 00007fa2c9c5c670
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/10 10:57 android13-5.15-lts 79bd336c7a94 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 BUG: soft lockup in sys_readlink
2024/04/12 18:31 android13-5.15-lts 993bed180178 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf BUG: soft lockup in sys_readlink
* Struck through repros no longer work on HEAD.