[syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2f8c4f506285 Merge tag 'auxdisplay-for-v6.11-tag1' of git:..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=107c2903980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973
dashboard link: https://syzkaller.appspot.com/bug?extid=4fc98ed414ae63d1ada2
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/beafa5a4d4f9/disk-2f8c4f50.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e58aee7103bd/vmlinux-2f8c4f50.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92d87af85377/bzImage-2f8c4f50.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com

INFO: task syz.0.1705:11501 blocked for more than 143 seconds.
      Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1705      state:D stack:24064 pid:11501 tgid:11500 ppid:11214  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 io_schedule+0x8d/0x110 kernel/sched/core.c:7401
 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1307
 folio_lock include/linux/pagemap.h:1050 [inline]
 z_erofs_fill_bio_vec fs/erofs/zdata.c:1470 [inline]
 z_erofs_submit_queue fs/erofs/zdata.c:1650 [inline]
 z_erofs_runqueue+0xa8c/0x2010 fs/erofs/zdata.c:1732
 z_erofs_readahead+0xbae/0xf00 fs/erofs/zdata.c:1863
 read_pages+0x180/0x840 mm/readahead.c:160
 page_cache_ra_unbounded+0x6ce/0x7f0 mm/readahead.c:273
 do_page_cache_ra mm/readahead.c:303 [inline]
 force_page_cache_ra+0x280/0x2f0 mm/readahead.c:332
 force_page_cache_readahead mm/internal.h:338 [inline]
 generic_fadvise+0x528/0x840 mm/fadvise.c:106
 vfs_fadvise mm/fadvise.c:185 [inline]
 ksys_fadvise64_64 mm/fadvise.c:199 [inline]
 __do_sys_fadvise64 mm/fadvise.c:214 [inline]
 __se_sys_fadvise64 mm/fadvise.c:212 [inline]
 __x64_sys_fadvise64+0x145/0x190 mm/fadvise.c:212
 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: 0033:0x7f0148f77299
RSP: 002b:00007f0149d48048 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd
RAX: ffffffffffffffda RBX: 00007f0149105f80 RCX: 00007f0148f77299
RDX: 0000000000000000 RSI: 0000000000e0ffff RDI: 0000000000000004
RBP: 00007f0148fe48e6 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f0149105f80 R15: 00007fffc733a208
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6620
3 locks held by kworker/u8:6/1106:
 #0: ffff88802a670948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88802a670948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc900042bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900042bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194
4 locks held by kworker/u8:9/2557:
 #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc900094efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900094efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc72ed0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8e93ca38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline]
 #3: ffffffff8e93ca38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958
1 lock held by syslogd/4657:
 #0: ffff8880b933ea18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560
2 locks held by dhcpcd/4889:
 #0: ffff88806adb9678 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: netlink_dump+0xcb/0xd80 net/netlink/af_netlink.c:2271
 #1: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #1: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6506
2 locks held by getty/4977:
 #0: ffff88802f6520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
1 lock held by syz.0.1705/11501:
 #0: ffff88801de44880 (mapping.invalidate_lock#9){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:854 [inline]
 #0: ffff88801de44880 (mapping.invalidate_lock#9){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xf7/0x7f0 mm/readahead.c:225
2 locks held by kworker/u9:3/12128:
1 lock held by syz-executor/12808:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz-executor/12935:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz-executor/12997:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz-executor/13018:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz.0.1882/13025:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48f/0x2400 drivers/net/tun.c:3120
1 lock held by syz-executor/13026:
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:379
 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>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4664 Comm: klogd Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:unwind_next_frame+0x6c5/0x2a00 arch/x86/kernel/unwind_orc.c:505
Code: 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 93 1b 00 00 0f b6 5d 01 83 e3 07 48 89 df 48 c7 c6 80 32 7a 8e e8 ce 7a 52 00 48 85 db <74> 16 83 fb 01 75 1e e8 3f 75 52 00 4d 89 f7 48 8b 2c 24 e9 8c 14
RSP: 0018:ffffc9000931f228 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffff8880604fbc00
RDX: 0000000000000002 RSI: ffffffff8e7a3280 RDI: 0000000000000003
RBP: ffffffff9140d5f0 R08: 0000000000000003 R09: ffffffff81410e12
R10: 0000000000000002 R11: ffff8880604fbc00 R12: ffffffff90957014
R13: dffffc0000000000 R14: 1ffff92001263e60 R15: ffffffff9140d5ec
FS:  00007f3530fce380(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe45b7c2270 CR3: 000000002dd0a000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0x151/0x1b0 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
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:4158 [inline]
 __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4177
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
 unix_dgram_sendmsg+0x6d3/0x1f80 net/unix/af_unix.c:2030
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2204
 __do_sys_sendto net/socket.c:2216 [inline]
 __se_sys_sendto net/socket.c:2212 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2212
 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: 0033:0x7f35311309b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffeb7c54b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f35311309b5
RDX: 0000000000000053 RSI: 0000555babb61eb0 RDI: 0000000000000003
RBP: 0000555babb5a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007f35312be212 R14: 00007ffeb7c54c88 R15: 0000000000000000
 </TASK>


---
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Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[Gao Xiang]

On 2024/7/27 12:44, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    2f8c4f506285 Merge tag 'auxdisplay-for-v6.11-tag1' of git:..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=107c2903980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973
> dashboard link: https://syzkaller.appspot.com/bug?extid=4fc98ed414ae63d1ada2
> 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.

I have no idea if it relates to the issue I'm now addressing:
https://lore.kernel.org/r/20240728154913.4023977-1-hsiangkao@linux.alibaba.com

Maybe that is another issue just out of some crafted
images, since there is no valid reproducer I will wait
for the proper reproducer for now.

Thanks,
Gao Xiang

> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/beafa5a4d4f9/disk-2f8c4f50.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/e58aee7103bd/vmlinux-2f8c4f50.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/92d87af85377/bzImage-2f8c4f50.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com
> 
> INFO: task syz.0.1705:11501 blocked for more than 143 seconds.
>        Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:syz.0.1705      state:D stack:24064 pid:11501 tgid:11500 ppid:11214  flags:0x00004004
> Call Trace:
>   <TASK>
>   context_switch kernel/sched/core.c:5188 [inline]
>   __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
>   __schedule_loop kernel/sched/core.c:6606 [inline]
>   schedule+0x14b/0x320 kernel/sched/core.c:6621
>   io_schedule+0x8d/0x110 kernel/sched/core.c:7401
>   folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1307
>   folio_lock include/linux/pagemap.h:1050 [inline]
>   z_erofs_fill_bio_vec fs/erofs/zdata.c:1470 [inline]
>   z_erofs_submit_queue fs/erofs/zdata.c:1650 [inline]
>   z_erofs_runqueue+0xa8c/0x2010 fs/erofs/zdata.c:1732
>   z_erofs_readahead+0xbae/0xf00 fs/erofs/zdata.c:1863
>   read_pages+0x180/0x840 mm/readahead.c:160
>   page_cache_ra_unbounded+0x6ce/0x7f0 mm/readahead.c:273
>   do_page_cache_ra mm/readahead.c:303 [inline]
>   force_page_cache_ra+0x280/0x2f0 mm/readahead.c:332
>   force_page_cache_readahead mm/internal.h:338 [inline]
>   generic_fadvise+0x528/0x840 mm/fadvise.c:106
>   vfs_fadvise mm/fadvise.c:185 [inline]
>   ksys_fadvise64_64 mm/fadvise.c:199 [inline]
>   __do_sys_fadvise64 mm/fadvise.c:214 [inline]
>   __se_sys_fadvise64 mm/fadvise.c:212 [inline]
>   __x64_sys_fadvise64+0x145/0x190 mm/fadvise.c:212
>   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: 0033:0x7f0148f77299
> RSP: 002b:00007f0149d48048 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd
> RAX: ffffffffffffffda RBX: 00007f0149105f80 RCX: 00007f0148f77299
> RDX: 0000000000000000 RSI: 0000000000e0ffff RDI: 0000000000000004
> RBP: 00007f0148fe48e6 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
> R13: 000000000000000b R14: 00007f0149105f80 R15: 00007fffc733a208
>   </TASK>
> 
> Showing all locks held in the system:
> 1 lock held by khungtaskd/30:
>   #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
>   #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
>   #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6620
> 3 locks held by kworker/u8:6/1106:
>   #0: ffff88802a670948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
>   #0: ffff88802a670948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
>   #1: ffffc900042bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
>   #1: ffffc900042bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
>   #2: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194
> 4 locks held by kworker/u8:9/2557:
>   #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
>   #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
>   #1: ffffc900094efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
>   #1: ffffc900094efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
>   #2: ffffffff8fc72ed0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
>   #3: ffffffff8e93ca38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline]
>   #3: ffffffff8e93ca38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958
> 1 lock held by syslogd/4657:
>   #0: ffff8880b933ea18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560
> 2 locks held by dhcpcd/4889:
>   #0: ffff88806adb9678 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: netlink_dump+0xcb/0xd80 net/netlink/af_netlink.c:2271
>   #1: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #1: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6506
> 2 locks held by getty/4977:
>   #0: ffff88802f6520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
>   #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
> 1 lock held by syz.0.1705/11501:
>   #0: ffff88801de44880 (mapping.invalidate_lock#9){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:854 [inline]
>   #0: ffff88801de44880 (mapping.invalidate_lock#9){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xf7/0x7f0 mm/readahead.c:225
> 2 locks held by kworker/u9:3/12128:
> 1 lock held by syz-executor/12808:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
> 1 lock held by syz-executor/12935:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
> 1 lock held by syz-executor/12997:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
> 1 lock held by syz-executor/13018:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
> 1 lock held by syz.0.1882/13025:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48f/0x2400 drivers/net/tun.c:3120
> 1 lock held by syz-executor/13026:
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
>   #0: ffffffff8fc7fa48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
> 
> =============================================
> 
> NMI backtrace for cpu 1
> CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
> Call Trace:
>   <TASK>
>   __dump_stack lib/dump_stack.c:93 [inline]
>   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
>   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:162 [inline]
>   check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
>   watchdog+0xfee/0x1030 kernel/hung_task.c:379
>   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>
> Sending NMI from CPU 1 to CPUs 0:
> NMI backtrace for cpu 0
> CPU: 0 UID: 0 PID: 4664 Comm: klogd Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
> RIP: 0010:unwind_next_frame+0x6c5/0x2a00 arch/x86/kernel/unwind_orc.c:505
> Code: 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 93 1b 00 00 0f b6 5d 01 83 e3 07 48 89 df 48 c7 c6 80 32 7a 8e e8 ce 7a 52 00 48 85 db <74> 16 83 fb 01 75 1e e8 3f 75 52 00 4d 89 f7 48 8b 2c 24 e9 8c 14
> RSP: 0018:ffffc9000931f228 EFLAGS: 00000206
> RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffff8880604fbc00
> RDX: 0000000000000002 RSI: ffffffff8e7a3280 RDI: 0000000000000003
> RBP: ffffffff9140d5f0 R08: 0000000000000003 R09: ffffffff81410e12
> R10: 0000000000000002 R11: ffff8880604fbc00 R12: ffffffff90957014
> R13: dffffc0000000000 R14: 1ffff92001263e60 R15: ffffffff9140d5ec
> FS:  00007f3530fce380(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fe45b7c2270 CR3: 000000002dd0a000 CR4: 0000000000350ef0
> Call Trace:
>   <NMI>
>   </NMI>
>   <TASK>
>   arch_stack_walk+0x151/0x1b0 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
>   poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
>   __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
>   kasan_kmalloc include/linux/kasan.h:211 [inline]
>   __do_kmalloc_node mm/slub.c:4158 [inline]
>   __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4177
>   kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605
>   __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
>   alloc_skb include/linux/skbuff.h:1320 [inline]
>   alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526
>   sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
>   unix_dgram_sendmsg+0x6d3/0x1f80 net/unix/af_unix.c:2030
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x223/0x270 net/socket.c:745
>   __sys_sendto+0x3a4/0x4f0 net/socket.c:2204
>   __do_sys_sendto net/socket.c:2216 [inline]
>   __se_sys_sendto net/socket.c:2212 [inline]
>   __x64_sys_sendto+0xde/0x100 net/socket.c:2212
>   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: 0033:0x7f35311309b5
> Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
> RSP: 002b:00007ffeb7c54b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
> RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f35311309b5
> RDX: 0000000000000053 RSI: 0000555babb61eb0 RDI: 0000000000000003
> RBP: 0000555babb5a910 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
> R13: 00007f35312be212 R14: 00007ffeb7c54c88 R15: 0000000000000000
>   </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 syzkaller@googlegroups.com.
> 
> 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

Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    048499f92ed7 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1118b433980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5c686716759500c2
dashboard link: https://syzkaller.appspot.com/bug?extid=4fc98ed414ae63d1ada2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10d09f83980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10e3247b980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/66c48334a6dc/disk-048499f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a8e45cac172b/vmlinux-048499f9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/80940291bc58/Image-048499f9.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/f7747709ae10/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com

INFO: task syz-executor173:6412 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc4-syzkaller-g048499f92ed7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor173 state:D stack:0     pid:6412  tgid:6412  ppid:6411   flags:0x00000005
Call trace:
 __switch_to+0x314/0x560 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x13d4/0x2418 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xbc/0x238 kernel/sched/core.c:6621
 io_schedule+0x8c/0x124 kernel/sched/core.c:7401
 folio_wait_bit_common+0x65c/0xb90 mm/filemap.c:1307
 __folio_lock+0x2c/0x3c mm/filemap.c:1645
 folio_lock include/linux/pagemap.h:1050 [inline]
 z_erofs_fill_bio_vec fs/erofs/zdata.c:1470 [inline]
 z_erofs_submit_queue fs/erofs/zdata.c:1650 [inline]
 z_erofs_runqueue+0x838/0x17ec fs/erofs/zdata.c:1732
 z_erofs_readahead+0x858/0xc18 fs/erofs/zdata.c:1863
 read_pages+0x160/0x694 mm/readahead.c:160
 page_cache_ra_unbounded+0x484/0x584 mm/readahead.c:273
 do_page_cache_ra mm/readahead.c:303 [inline]
 force_page_cache_ra+0x22c/0x290 mm/readahead.c:332
 force_page_cache_readahead mm/internal.h:338 [inline]
 generic_fadvise+0x3e8/0x6a0 mm/fadvise.c:106
 vfs_fadvise mm/fadvise.c:185 [inline]
 ksys_fadvise64_64 mm/fadvise.c:199 [inline]
 __do_sys_fadvise64_64 mm/fadvise.c:207 [inline]
 __se_sys_fadvise64_64 mm/fadvise.c:205 [inline]
 __arm64_sys_fadvise64_64+0x12c/0x174 mm/fadvise.c:205
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffff80008f6edb60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:325
2 locks held by getty/6155:
 #0: ffff0000d23b60a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009836e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41c/0x1228 drivers/tty/n_tty.c:2211
1 lock held by syz-executor173/6412:
 #0: ffff0000deee0330 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:854 [inline]
 #0: ffff0000deee0330 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: page_cache_ra_unbounded+0xc8/0x584 mm/readahead.c:225

=============================================



---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[Gao Xiang]

> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-next

Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git/dev-next: failed to run ["git" "fetch" "--force" "3c3147cbfa20ccaaeceb3a944332ec2db65b4a22" "dev-next"]: exit status 128
fatal: couldn't find remote ref dev-next



Tested on:

commit:         [unknown 
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=5c686716759500c2
dashboard link: https://syzkaller.appspot.com/bug?extid=4fc98ed414ae63d1ada2
compiler:       
userspace arch: arm64

Note: no patches were applied.

Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[Gao Xiang]

> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-test

Re: [syzbot] [erofs?] INFO: task hung in z_erofs_runqueue

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com
Tested-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com

Tested on:

commit:         e96d8572 erofs: handle overlapped pclusters out of cra..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-test
console output: https://syzkaller.appspot.com/x/log.txt?x=10d14e8f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=264b71bd0896c2bf
dashboard link: https://syzkaller.appspot.com/bug?extid=4fc98ed414ae63d1ada2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.