================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x74/0x1ff0 kernel/locking/lockdep.c:4882 Read of size 8 at addr ffff888020716368 by task syz-executor.4/8357 CPU: 0 PID: 8357 Comm: syz-executor.4 Not tainted 5.15.156-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 __lock_acquire+0x74/0x1ff0 kernel/locking/lockdep.c:4882 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4785 Code: 45 31 c9 68 b7 90 59 81 e8 ec 1a 09 00 48 83 c4 08 4c 89 ff e8 60 da fe ff 66 90 4c 89 ff e8 b6 8a cd 08 e8 f1 4b 2d 00 fb 5b <41> 5c 41 5d 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 87 RSP: 0018:ffffc90002f87998 EFLAGS: 00000286 RAX: f09a1548ee9cb500 RBX: ffff888016d99df4 RCX: ffffffff913edf03 RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f380 RBP: ffffc90002f87a10 R08: ffffffff8186dd10 R09: ffffed1017347469 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff11017347613 R14: ffff8880b9a3b098 R15: ffff8880b9a3a340 finish_task_switch+0x134/0x630 kernel/sched/core.c:4902 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x1bc/0x7b0 kernel/time/hrtimer.c:2045 hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1313 [inline] __se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1290 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc04a20e2b5 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007ffec5e13b50 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007fc04a310f80 RCX: 00007fc04a20e2b5 RDX: 00007ffec5e13b90 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc04a312980 R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000039938 R13: 00000000000396e6 R14: 00007ffec5e13d60 R15: 00007fc04a199cb0 Allocated by task 2: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0xb60 kernel/fork.c:894 copy_process+0x5eb/0x3ef0 kernel/fork.c:2038 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 create_kthread kernel/kthread.c:357 [inline] kthreadd+0x57a/0x740 kernel/kthread.c:701 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Freed by task 14: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0xa15/0x1650 kernel/rcu/tree.c:2763 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3007 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 mutex_optimistic_spin+0x299/0x300 kernel/locking/mutex.c:503 __mutex_lock_common+0x1ff/0x25a0 kernel/locking/mutex.c:599 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 linkwatch_event+0xa/0x50 net/core/link_watch.c:251 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Second to last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3007 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1966 [inline] do_nanosleep+0x164/0x7b0 kernel/time/hrtimer.c:2042 hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1313 [inline] __se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1290 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888020715940 which belongs to the cache task_struct of size 7360 The buggy address is located 2600 bytes inside of 7360-byte region [ffff888020715940, ffff888020717600) The buggy address belongs to the page: page:ffffea000081c400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20710 head:ffffea000081c400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801e4f7081 flags: 0xfff80000010200(slab|head|node=0|zone=1|lastcpupid=0xfff) raw: 00fff80000010200 ffffea0000721400 0000000200000002 ffff888011deb3c0 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88801e4f7081 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9, ts 9911300786, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] kmem_cache_alloc_node+0x1ba/0x2c0 mm/slub.c:3256 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct+0x57/0xb60 kernel/fork.c:894 copy_process+0x5eb/0x3ef0 kernel/fork.c:2038 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 call_usermodehelper_exec_work+0x58/0x220 kernel/umh.c:174 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 page_owner free stack trace missing Memory state around the buggy address: ffff888020716200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020716280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888020716300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020716380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020716400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 45 31 c9 xor %r9d,%r9d 3: 68 b7 90 59 81 push $0xffffffff815990b7 8: e8 ec 1a 09 00 call 0x91af9 d: 48 83 c4 08 add $0x8,%rsp 11: 4c 89 ff mov %r15,%rdi 14: e8 60 da fe ff call 0xfffeda79 19: 66 90 xchg %ax,%ax 1b: 4c 89 ff mov %r15,%rdi 1e: e8 b6 8a cd 08 call 0x8cd8ad9 23: e8 f1 4b 2d 00 call 0x2d4c19 28: fb sti 29: 5b pop %rbx * 2a: 41 5c pop %r12 <-- trapping instruction 2c: 41 5d pop %r13 2e: 41 5e pop %r14 30: 41 5f pop %r15 32: c3 ret 33: 44 89 f1 mov %r14d,%ecx 36: 80 e1 07 and $0x7,%cl 39: 80 c1 03 add $0x3,%cl 3c: 38 c1 cmp %al,%cl 3e: 7c 87 jl 0xffffffc7