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In-Reply-To: <20260328214408.2990597-1-ljykernel@163.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69c80fa8.a70a0220.97f31.0002.GAE@google.com> Subject: [syzbot ci] Re: mm/page_owner: warn when stack trace depth hits PAGE_OWNER_STACK_DEPTH limit From: syzbot ci To: akpm@linux-foundation.org, linux-mm@kvack.org, ljykernel@163.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v2] mm/page_owner: warn when stack trace depth hits PAGE_OWNER_STACK_DEPTH limit https://lore.kernel.org/all/20260328214408.2990597-1-ljykernel@163.com * [PATCH v2] mm/page_owner: warn when stack trace depth hits PAGE_OWNER_STACK_DEPTH limit and found the following issue: possible deadlock in hrtimer_start_range_ns Full report is available here: https://ci.syzbot.org/series/aa38ba8f-44db-4d01-8965-ed5a27174f71 *** possible deadlock in hrtimer_start_range_ns tree: mm-new URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git base: f46991f1780ef97efff3b668627b763581032067 arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/2808cd4a-ad2f-49d0-8b68-eb99aeb06ed6/config syz repro: https://ci.syzbot.org/findings/6c04900a-b825-4465-90f4-694fc3a9d29b/syz_repro page_owner: stack depth 16 exceeds limit 16 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ klogd/5246 is trying to acquire lock: ffffffff8e750a00 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2026 [inline] ffffffff8e750a00 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x2cf/0x560 kernel/printk/printk.c:2478 but task is already holding lock: ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:172 [inline] ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xc8/0x1ff0 kernel/time/hrtimer.c:1328 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (hrtimer_bases.lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:172 [inline] hrtimer_start_range_ns+0xc8/0x1ff0 kernel/time/hrtimer.c:1328 rpm_suspend+0x12d4/0x1750 drivers/base/power/runtime.c:632 __pm_runtime_idle+0x12f/0x1a0 drivers/base/power/runtime.c:1129 pm_runtime_put include/linux/pm_runtime.h:551 [inline] __device_attach+0x34f/0x450 drivers/base/dd.c:1111 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1148 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613 device_add+0x7b6/0xb70 drivers/base/core.c:3691 serdev_controller_add+0x85/0x640 drivers/tty/serdev/core.c:775 serdev_tty_port_register+0x159/0x260 drivers/tty/serdev/serdev-ttyport.c:291 tty_port_register_device_attr_serdev+0xe7/0x170 drivers/tty/tty_port.c:187 serial_core_add_one_port drivers/tty/serial/serial_core.c:3109 [inline] serial_core_register_port+0x1123/0x28a0 drivers/tty/serial/serial_core.c:3307 serial8250_register_8250_port+0x1658/0x1fd0 drivers/tty/serial/8250/8250_core.c:822 serial_pnp_probe+0x568/0x7f0 drivers/tty/serial/8250/8250_pnp.c:480 pnp_device_probe+0x30b/0x4c0 drivers/pnp/driver.c:111 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:721 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:863 driver_probe_device+0x4f/0x240 drivers/base/dd.c:893 __driver_attach+0x34c/0x640 drivers/base/dd.c:1287 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383 bus_add_driver+0x345/0x670 drivers/base/bus.c:756 driver_register+0x23a/0x320 drivers/base/driver.c:249 serial8250_init+0x8f/0x160 drivers/tty/serial/8250/8250_platform.c:317 do_one_initcall+0x250/0x8d0 init/main.c:1382 do_initcall_level+0x104/0x190 init/main.c:1444 do_initcalls+0x59/0xa0 init/main.c:1460 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692 kernel_init+0x1d/0x1d0 init/main.c:1582 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&dev->power.lock){-...}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 __pm_runtime_resume+0x10f/0x180 drivers/base/power/runtime.c:1196 pm_runtime_get include/linux/pm_runtime.h:494 [inline] __uart_start+0x171/0x460 drivers/tty/serial/serial_core.c:149 uart_write+0x265/0xa10 drivers/tty/serial/serial_core.c:633 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0xd84/0x12a0 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write+0x559/0xa20 drivers/tty/tty_io.c:1081 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:717 [inline] serial8250_console_write+0x150/0x1ba0 drivers/tty/serial/8250/8250_port.c:3316 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 register_console+0xbc2/0xfa0 kernel/printk/printk.c:4208 univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:515 console_init+0x10b/0x4d0 kernel/printk/printk.c:4407 start_kernel+0x22b/0x3d0 init/main.c:1147 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 console_trylock_spinning kernel/printk/printk.c:2026 [inline] vprintk_emit+0x2eb/0x560 kernel/printk/printk.c:2478 _printk+0xdd/0x130 kernel/printk/printk.c:2504 save_stack+0x238/0x2a0 mm/page_owner.c:167 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:344 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1860 prep_new_page mm/page_alloc.c:1868 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3948 alloc_frozen_pages_nolock_noprof+0xac/0x140 mm/page_alloc.c:7795 alloc_slab_page mm/slub.c:3287 [inline] allocate_slab+0xf2/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] ___slab_alloc+0x150/0x6b0 mm/slub.c:4413 __slab_alloc_node mm/slub.c:4479 [inline] slab_alloc_node mm/slub.c:4854 [inline] kmem_cache_alloc_noprof+0x12d/0x650 mm/slub.c:4873 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x156/0x590 lib/debugobjects.c:420 debug_objects_fill_pool lib/debugobjects.c:742 [inline] debug_object_activate+0x4a3/0x580 lib/debugobjects.c:831 debug_hrtimer_activate kernel/time/hrtimer.c:446 [inline] debug_activate kernel/time/hrtimer.c:485 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1089 __hrtimer_start_range_ns kernel/time/hrtimer.c:1271 [inline] hrtimer_start_range_ns+0x15ea/0x1ff0 kernel/time/hrtimer.c:1330 hrtimer_start include/linux/hrtimer.h:244 [inline] dummy_timer+0x4436/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:2008 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 check_kcov_mode kernel/kcov.c:183 [inline] __sanitizer_cov_trace_pc+0x30/0x70 kernel/kcov.c:217 number+0xc0f/0xf80 lib/vsprintf.c:571 vsnprintf+0x8e5/0xee0 lib/vsprintf.c:2912 sprintf+0xe7/0x140 lib/vsprintf.c:3111 print_time kernel/printk/printk.c:1359 [inline] info_print_prefix+0x16b/0x360 kernel/printk/printk.c:1385 record_print_text+0x176/0x450 kernel/printk/printk.c:1434 syslog_print+0x3b0/0x610 kernel/printk/printk.c:1645 do_syslog+0x583/0x7d0 kernel/printk/printk.c:1763 __do_sys_syslog kernel/printk/printk.c:1855 [inline] __se_sys_syslog kernel/printk/printk.c:1853 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1853 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: console_owner --> &dev->power.lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(&dev->power.lock); lock(hrtimer_bases.lock); lock(console_owner); *** DEADLOCK *** 4 locks held by klogd/5246: #0: ffffffff8e750948 (syslog_lock){+.+.}-{4:4}, at: syslog_print+0x4ad/0x610 kernel/printk/printk.c:1663 #1: ffff88816eebc018 (&dum_hcd->dum->lock){..-.}-{3:3}, at: dummy_timer+0x151/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1821 #2: ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:172 [inline] #2: ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xc8/0x1ff0 kernel/time/hrtimer.c:1328 #3: ffffffff8ef08700 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_objects_fill_pool lib/debugobjects.c:741 [inline] #3: ffffffff8ef08700 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_object_activate+0x47a/0x580 lib/debugobjects.c:831 stack backtrace: CPU: 0 UID: 0 PID: 5246 Comm: klogd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 console_trylock_spinning kernel/printk/printk.c:2026 [inline] vprintk_emit+0x2eb/0x560 kernel/printk/printk.c:2478 _printk+0xdd/0x130 kernel/printk/printk.c:2504 save_stack+0x238/0x2a0 mm/page_owner.c:167 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:344 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1860 prep_new_page mm/page_alloc.c:1868 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3948 alloc_frozen_pages_nolock_noprof+0xac/0x140 mm/page_alloc.c:7795 alloc_slab_page mm/slub.c:3287 [inline] allocate_slab+0xf2/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] ___slab_alloc+0x150/0x6b0 mm/slub.c:4413 __slab_alloc_node mm/slub.c:4479 [inline] slab_alloc_node mm/slub.c:4854 [inline] kmem_cache_alloc_noprof+0x12d/0x650 mm/slub.c:4873 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x156/0x590 lib/debugobjects.c:420 debug_objects_fill_pool lib/debugobjects.c:742 [inline] debug_object_activate+0x4a3/0x580 lib/debugobjects.c:831 debug_hrtimer_activate kernel/time/hrtimer.c:446 [inline] debug_activate kernel/time/hrtimer.c:485 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1089 __hrtimer_start_range_ns kernel/time/hrtimer.c:1271 [inline] hrtimer_start_range_ns+0x15ea/0x1ff0 kernel/time/hrtimer.c:1330 hrtimer_start include/linux/hrtimer.h:244 [inline] dummy_timer+0x4436/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:2008 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x30/0x70 kernel/kcov.c:217 Code: 04 24 65 48 8b 0d 08 4b 56 11 65 8b 15 29 4b 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00 00 74 2c <8b> 91 80 16 00 00 83 fa 02 75 21 48 8b 91 88 16 00 00 48 8b 32 48 RSP: 0018:ffffc900036676b8 EFLAGS: 00000246 RAX: ffffffff8ba85ecf RBX: 0000000000000031 RCX: ffff888111ff0000 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffc90003667742 RBP: ffffc900036677e0 R08: ffffc90003667757 R09: 0000000000000000 R10: ffffc90003667740 R11: fffff520006cceeb R12: ffffc90003667acd R13: dffffc0000000000 R14: ffffc90003667ace R15: 0000000000000002 number+0xc0f/0xf80 lib/vsprintf.c:571 vsnprintf+0x8e5/0xee0 lib/vsprintf.c:2912 sprintf+0xe7/0x140 lib/vsprintf.c:3111 print_time kernel/printk/printk.c:1359 [inline] info_print_prefix+0x16b/0x360 kernel/printk/printk.c:1385 record_print_text+0x176/0x450 kernel/printk/printk.c:1434 syslog_print+0x3b0/0x610 kernel/printk/printk.c:1645 do_syslog+0x583/0x7d0 kernel/printk/printk.c:1763 __do_sys_syslog kernel/printk/printk.c:1855 [inline] __se_sys_syslog kernel/printk/printk.c:1853 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1853 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1089379fa7 Code: 73 01 c3 48 8b 0d 81 ce 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 ce 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffed757a078 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f10895184a0 RCX: 00007f1089379fa7 RDX: 00000000000003ff RSI: 00007f10895184a0 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000007 R09: 7e78de0d48eb7984 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f10895184a0 R13: 00007f1089508212 R14: 00007f108951855a R15: 00007f108951855a ---------------- Code disassembly (best guess): 0: 04 24 add $0x24,%al 2: 65 48 8b 0d 08 4b 56 mov %gs:0x11564b08(%rip),%rcx # 0x11564b12 9: 11 a: 65 8b 15 29 4b 56 11 mov %gs:0x11564b29(%rip),%edx # 0x11564b3a 11: 81 e2 00 01 ff 00 and $0xff0100,%edx 17: 74 11 je 0x2a 19: 81 fa 00 01 00 00 cmp $0x100,%edx 1f: 75 35 jne 0x56 21: 83 b9 a4 16 00 00 00 cmpl $0x0,0x16a4(%rcx) 28: 74 2c je 0x56 * 2a: 8b 91 80 16 00 00 mov 0x1680(%rcx),%edx <-- trapping instruction 30: 83 fa 02 cmp $0x2,%edx 33: 75 21 jne 0x56 35: 48 8b 91 88 16 00 00 mov 0x1688(%rcx),%rdx 3c: 48 8b 32 mov (%rdx),%rsi 3f: 48 rex.W *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com.