Re: [syzbot] [mm?] INFO: rcu detected stall in sys_symlinkat (5)

[syzbot <syzbot+9618c3b34a3062164a21@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    9b2ffa6148b1 Merge tag 'mtd/fixes-for-6.13-rc5' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15f774c4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4c4096b0d467a682
dashboard link: https://syzkaller.appspot.com/bug?extid=9618c3b34a3062164a21
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=12ec0018580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dbe249d9f678/disk-9b2ffa61.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef6ad79e83bf/vmlinux-9b2ffa61.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4d67490d157d/bzImage-9b2ffa61.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9618c3b34a3062164a21@syzkaller.appspotmail.com

bridge0: received packet on veth0_to_hsr with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6445/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=15553, q=788 ncpus=2)
task:syz-executor    state:R  running task     stack:26704 pid:6445  tgid:6445  ppid:5936   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078
 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853
Code: 2b 00 74 08 4c 89 f7 e8 0a a0 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000b26f5c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200164dec4 RCX: ffff888026730ad8
RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5edce0
RBP: ffffc9000b26f708 R08: ffffffff94270887 R09: 1ffffffff284e110
R10: dffffc0000000000 R11: fffffbfff284e111 R12: 1ffff9200164dec0
R13: dffffc0000000000 R14: ffffc9000b26f620 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 page_ext_get+0x3d/0x2a0 mm/page_ext.c:525
 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148
 page_table_check_free include/linux/page_table_check.h:41 [inline]
 free_pages_prepare mm/page_alloc.c:1128 [inline]
 free_unref_page+0xd40/0x1000 mm/page_alloc.c:2659
 __slab_free+0x2c2/0x380 mm/slub.c:4524
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4310
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
 tomoyo_path_symlink+0xde/0x120 security/tomoyo/tomoyo.c:212
 security_path_symlink+0x16f/0x370 security/security.c:1979
 do_symlinkat+0x136/0x3a0 fs/namei.c:4693
 __do_sys_symlinkat fs/namei.c:4711 [inline]
 __se_sys_symlinkat fs/namei.c:4708 [inline]
 __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4708
 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: 0033:0x7f32f9b852a7
RSP: 002b:00007ffc31bdedb8 EFLAGS: 00000202 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f32f9b852a7
RDX: 00007f32f9c032ad RSI: 00000000ffffff9c RDI: 00007f32f9c01e6b
RBP: 00007ffc31bdedec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000005f
R13: 000000000002cd05 R14: 00007ffc31bdee40 R15: 00007ffc31bdee40
 </TASK>
rcu: rcu_preempt kthread starved for 8644 jiffies! g15553 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:25624 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247
 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>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6417 Comm: kworker/u8:8 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound macvlan_process_broadcast
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x86/0x290 mm/kasan/generic.c:189
Code: 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 <0f> 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00 00 45 89 dc
RSP: 0018:ffffc90000006280 EFLAGS: 00000246
RAX: ffffc90000006501 RBX: 1ffff92000000c7e RCX: ffffffff814bb57b
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900000063f0
RBP: ffffffffffffffff R08: ffffc900000063ff R09: 1ffff92000000c7f
R10: dffffc0000000000 R11: fffff52000000c7f R12: ffffc90000008000
R13: ffffc900000063a0 R14: dffffc0000000001 R15: fffff52000000c80
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdae10578c CR3: 000000000e736000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __asan_memset+0x23/0x50 mm/kasan/shadow.c:84
 unwind_next_frame+0xcfb/0x22d0 arch/x86/kernel/unwind_orc.c:592
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4715
 skb_kfree_head net/core/skbuff.c:1084 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x677/0x8a0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242
 hsr_forward_skb+0xbce/0x2b50
 hsr_dev_xmit+0x195/0x210 net/hsr/hsr_device.c:235
 __netdev_start_xmit include/linux/netdevice.h:5002 [inline]
 netdev_start_xmit include/linux/netdevice.h:5011 [inline]
 xmit_one net/core/dev.c:3590 [inline]
 dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3606
 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434
 dev_queue_xmit include/linux/netdevice.h:3168 [inline]
 br_dev_queue_push_xmit+0x726/0x900 net/bridge/br_forward.c:53
 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314
 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66
 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314
 __br_forward+0x489/0x660 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190
 br_flood+0x2e4/0x660 net/bridge/br_forward.c:236
 br_handle_frame_finish+0x18ba/0x1fe0 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:299 [inline]
 br_handle_frame+0xbf8/0x1530 net/bridge/br_input.c:424
 __netif_receive_skb_core+0x14eb/0x4690 net/core/dev.c:5566
 __netif_receive_skb_one_core net/core/dev.c:5670 [inline]
 __netif_receive_skb+0x12f/0x650 net/core/dev.c:5785
 process_backlog+0x662/0x15b0 net/core/dev.c:6117
 __napi_poll+0xcb/0x490 net/core/dev.c:6883
 napi_poll net/core/dev.c:6952 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7074
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 netif_rx+0x83/0x90 net/core/dev.c:5257
 macvlan_broadcast+0x3c4/0x670 drivers/net/macvlan.c:290
 macvlan_process_broadcast+0x50e/0x7f0 drivers/net/macvlan.c:338
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa66/0x1840 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>
net_ratelimit: 3220 callbacks suppressed
bridge0: received packet on vlan0 with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on veth0_to_hsr with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on veth0_to_hsr with own address as source address (addr:f6:90:ad:41:80:9a, vlan:0)
bridge0: received packet on vlan0 with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on veth0_to_hsr with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
net_ratelimit: 4254 callbacks suppressed
bridge0: received packet on veth0_to_hsr with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on vlan0 with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on macvlan0 with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on veth0_to_hsr with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)
bridge0: received packet on vlan0 with own address as source address (addr:de:4f:11:41:a2:64, vlan:0)


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