Hello, syzbot found the following issue on: HEAD commit: a2c65a9d0568 net: dsa: fall back to default tagger if we c.. git tree: net console+strace: https://syzkaller.appspot.com/x/log.txt?x=10cfb046880000 kernel config: https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8 dashboard link: https://syzkaller.appspot.com/bug?extid=c39682e86c9d84152f93 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=159ad4fc880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=159d8591880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c43fc9428e96/disk-a2c65a9d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ef96432b3e62/vmlinux-a2c65a9d.xz kernel image: https://storage.googleapis.com/syzbot-assets/ee926615bbfc/bzImage-a2c65a9d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c39682e86c9d84152f93@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc2-syzkaller-00201-ga2c65a9d0568 #0 Not tainted ------------------------------------------------------ syz-executor229/3606 is trying to acquire lock: ffffffff8be35130 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_inc+0xe/0x20 kernel/jump_label.c:158 but task is already holding lock: ffffffff8bfda0c8 (freezer_mutex){+.+.}-{3:3}, at: freezer_change_state kernel/cgroup/legacy_freezer.c:387 [inline] ffffffff8bfda0c8 (freezer_mutex){+.+.}-{3:3}, at: freezer_write+0x98/0xa50 kernel/cgroup/legacy_freezer.c:426 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (freezer_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 freezer_attach+0x70/0x1f0 kernel/cgroup/legacy_freezer.c:163 cgroup_migrate_execute+0xbcf/0x1230 kernel/cgroup/cgroup.c:2615 cgroup_attach_task+0x41c/0x870 kernel/cgroup/cgroup.c:2906 __cgroup1_procs_write.constprop.0+0x3be/0x4b0 kernel/cgroup/cgroup-v1.c:523 cgroup_file_write+0x1de/0x770 kernel/cgroup/cgroup.c:4057 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:330 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x127/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (cgroup_threadgroup_rwsem){++++}-{0:0}: percpu_down_write+0x4f/0x390 kernel/locking/percpu-rwsem.c:227 cgroup_attach_lock kernel/cgroup/cgroup.c:2431 [inline] cgroup_procs_write_start+0x151/0x630 kernel/cgroup/cgroup.c:2935 __cgroup_procs_write+0xd7/0x650 kernel/cgroup/cgroup.c:5135 cgroup_procs_write+0x22/0x50 kernel/cgroup/cgroup.c:5171 cgroup_file_write+0x1de/0x770 kernel/cgroup/cgroup.c:4057 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:330 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x127/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (cpu_hotplug_lock){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] cpus_read_lock+0x3e/0x140 kernel/cpu.c:310 static_key_slow_inc+0xe/0x20 kernel/jump_label.c:158 freezer_apply_state+0x1e1/0x260 kernel/cgroup/legacy_freezer.c:353 freezer_change_state kernel/cgroup/legacy_freezer.c:398 [inline] freezer_write+0x571/0xa50 kernel/cgroup/legacy_freezer.c:426 cgroup_file_write+0x1de/0x770 kernel/cgroup/cgroup.c:4057 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:330 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x127/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: cpu_hotplug_lock --> cgroup_threadgroup_rwsem --> freezer_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(freezer_mutex); lock(cgroup_threadgroup_rwsem); lock(freezer_mutex); lock(cpu_hotplug_lock); *** DEADLOCK *** 4 locks held by syz-executor229/3606: #0: ffff888079bc2460 (sb_writers#10){.+.+}-{0:0}, at: ksys_write+0x127/0x250 fs/read_write.c:637 #1: ffff88801fa91c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x28c/0x610 fs/kernfs/file.c:321 #2: ffff888145b99a00 (kn->active#56){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b0/0x610 fs/kernfs/file.c:322 #3: ffffffff8bfda0c8 (freezer_mutex){+.+.}-{3:3}, at: freezer_change_state kernel/cgroup/legacy_freezer.c:387 [inline] #3: ffffffff8bfda0c8 (freezer_mutex){+.+.}-{3:3}, at: freezer_write+0x98/0xa50 kernel/cgroup/legacy_freezer.c:426 stack backtrace: CPU: 0 PID: 3606 Comm: syz-executor229 Not tainted 6.1.0-rc2-syzkaller-00201-ga2c65a9d0568 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] cpus_read_lock+0x3e/0x140 kernel/cpu.c:310 static_key_slow_inc+0xe/0x20 kernel/jump_label.c:158 freezer_apply_state+0x1e1/0x260 kernel/cgroup/legacy_freezer.c:353 freezer_change_state kernel/cgroup/legacy_freezer.c:398 [inline] freezer_write+0x571/0xa50 kernel/cgroup/legacy_freezer.c:426 cgroup_file_write+0x1de/0x770 kernel/cgroup/cgroup.c:4057 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:330 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x127/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe89501f769 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 15 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff9816df18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe89501f769 RDX: 0000000000000007 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007fff9816df40 R09: 00007fff9816df40 R10: 00007fff9816df40 R11: 0000000000000246 R12: 00007fff9816df3c R13: 00007fff9816df50 R14: 00007fff9816df90 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
