================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x1fd0 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff8880252dc578 by task kworker/u4:2/14648 CPU: 1 PID: 14648 Comm: kworker/u4:2 Not tainted 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x142/0x170 mm/kasan/report.c:588 __lock_acquire+0x77/0x1fd0 kernel/locking/lockdep.c:5005 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb5/0x1440 kernel/sched/core.c:4226 call_timer_fn+0x17a/0x5f0 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x64f/0x860 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 __do_softirq+0x2b8/0x939 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu+0xf1/0x1b0 kernel/softirq.c:632 irq_exit_rcu+0x9/0x20 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x97/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x25a/0x530 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 54 58 7d 00 f6 44 24 61 02 0f 85 8a 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:ffffc90012457a20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200248af50 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8b6ab6e0 RDI: ffffffff8bbde0a0 RBP: ffffc90012457b80 R08: ffffffff90dd7367 R09: 1ffffffff21bae6c R10: dffffc0000000000 R11: fffffbfff21bae6d R12: 1ffff9200248af4c R13: dffffc0000000000 R14: ffffc90012457a80 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2700 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2781 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Allocated by task 2: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x66/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6c/0x3c0 mm/slab.h:763 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x1dd/0x310 mm/slub.c:3523 alloc_task_struct_node kernel/fork.c:173 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1110 copy_process+0x5d1/0x3fb0 kernel/fork.c:2332 kernel_clone+0x222/0x840 kernel/fork.c:2907 kernel_thread+0x1bc/0x230 kernel/fork.c:2969 create_kthread kernel/kthread.c:411 [inline] kthreadd+0x60c/0x810 kernel/kthread.c:764 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Freed by task 26875: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] kmem_cache_free+0x299/0x470 mm/slub.c:3831 put_task_struct include/linux/sched/task.h:136 [inline] delayed_put_task_struct+0x115/0x2c0 kernel/exit.c:227 rcu_do_batch kernel/rcu/tree.c:2158 [inline] rcu_core+0xad8/0x17c0 kernel/rcu/tree.c:2431 __do_softirq+0x2b8/0x939 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xad/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2681 [inline] call_rcu+0x167/0xa80 kernel/rcu/tree.c:2795 context_switch kernel/sched/core.c:5379 [inline] __schedule+0x1969/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 do_nanosleep+0x196/0x5f0 kernel/time/hrtimer.c:2047 hrtimer_nanosleep+0x226/0x460 kernel/time/hrtimer.c:2100 __do_sys_nanosleep kernel/time/hrtimer.c:2135 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:2121 [inline] __x64_sys_nanosleep+0x269/0x2c0 kernel/time/hrtimer.c:2121 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xad/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2681 [inline] call_rcu+0x167/0xa80 kernel/rcu/tree.c:2795 release_task+0x16d2/0x1810 wait_task_zombie kernel/exit.c:1184 [inline] wait_consider_task+0x1a94/0x2ef0 kernel/exit.c:1411 do_wait_thread kernel/exit.c:1474 [inline] __do_wait+0x1af/0x840 kernel/exit.c:1592 do_wait+0x1d8/0x540 kernel/exit.c:1626 kernel_wait4+0x2a2/0x3e0 kernel/exit.c:1785 __do_sys_wait4 kernel/exit.c:1813 [inline] __se_sys_wait4 kernel/exit.c:1809 [inline] __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1809 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff8880252dbb80 which belongs to the cache task_struct of size 7360 The buggy address is located 2552 bytes inside of freed 7360-byte region [ffff8880252dbb80, ffff8880252dd840) The buggy address belongs to the physical page: page:ffffea000094b600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x252d8 head:ffffea000094b600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888020959c41 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888014e51500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888020959c41 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 2, tgid 2 (kthreadd), ts 13815831172, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0x33ea/0x3570 mm/page_alloc.c:3312 __alloc_pages+0x255/0x680 mm/page_alloc.c:4568 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2133 alloc_slab_page+0x6a/0x170 mm/slub.c:1870 allocate_slab mm/slub.c:2017 [inline] new_slab+0x84/0x2f0 mm/slub.c:2070 ___slab_alloc+0xc8a/0x1330 mm/slub.c:3223 __slab_alloc mm/slub.c:3322 [inline] __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] kmem_cache_alloc_node+0x22b/0x310 mm/slub.c:3523 alloc_task_struct_node kernel/fork.c:173 [inline] dup_task_struct+0x57/0x7d0 kernel/fork.c:1110 copy_process+0x5d1/0x3fb0 kernel/fork.c:2332 kernel_clone+0x222/0x840 kernel/fork.c:2907 kernel_thread+0x1bc/0x230 kernel/fork.c:2969 create_kthread kernel/kthread.c:411 [inline] kthreadd+0x60c/0x810 kernel/kthread.c:764 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 page_owner free stack trace missing Memory state around the buggy address: ffff8880252dc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880252dc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880252dc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880252dc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880252dc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 54 58 7d 00 call 0x7d5860 c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 8a 01 00 00 jne 0x1a1 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25