================================================================== BUG: KASAN: slab-use-after-free in timer_is_static_object+0x80/0x90 kernel/time/timer.c:691 Read of size 8 at addr ffff888036b7b898 by task swapper/2/0 CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 timer_is_static_object+0x80/0x90 kernel/time/timer.c:691 lookup_object_or_alloc.part.0+0x420/0x590 lib/debugobjects.c:679 lookup_object_or_alloc lib/debugobjects.c:665 [inline] debug_object_activate+0x326/0x4c0 lib/debugobjects.c:820 debug_timer_activate kernel/time/timer.c:793 [inline] __mod_timer+0x814/0xd30 kernel/time/timer.c:1124 add_timer+0x62/0x90 kernel/time/timer.c:1249 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: a7 6c 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 83 55 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000187de8 EFLAGS: 00000286 RAX: 0000000000418db3 RBX: 0000000000000002 RCX: ffffffff8b60d2a9 RDX: 0000000000000000 RSI: ffffffff8da2c59c RDI: ffffffff8bf073c0 RBP: ffffed1003bd4920 R08: 0000000000000001 R09: ffffed100d4c6655 R10: ffff88806a6332ab R11: 0000000000000001 R12: 0000000000000002 R13: ffff88801dea4900 R14: ffffffff908216d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 Allocated by task 7673: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] rose_add_node net/rose/rose_route.c:85 [inline] rose_rt_ioctl+0x880/0x2580 net/rose/rose_route.c:748 rose_ioctl+0x64d/0x7c0 net/rose/af_rose.c:1381 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 0: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6849 rose_neigh_put include/net/rose.h:166 [inline] rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 The buggy address belongs to the object at ffff888036b7b800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 152 bytes inside of freed 512-byte region [ffff888036b7b800, ffff888036b7ba00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x36b78 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b442c80 ffffea0001968a00 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442c80 ffffea0001968a00 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000dade01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5936, tgid 5936 (syz-executor), ts 55623898411, free_ts 55617808054 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5178 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab mm/slub.c:3232 [inline] new_slab+0x24a/0x360 mm/slub.c:3286 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4655 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0x501/0x880 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3809 addrconf_f6i_alloc+0x2da/0x660 net/ipv6/route.c:4678 fixup_permanent_addr net/ipv6/addrconf.c:3583 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3622 [inline] addrconf_notify+0x10a1/0x19e0 net/ipv6/addrconf.c:3694 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9676 netif_change_flags+0x108/0x160 net/core/dev.c:9705 page last free pid 5936 tgid 5936 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901 discard_slab mm/slub.c:3330 [inline] __put_partials+0x130/0x170 mm/slub.c:3876 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5340 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] netlink_ack+0x15d/0xb80 net/netlink/af_netlink.c:2489 netlink_rcv_skb+0x332/0x420 net/netlink/af_netlink.c:2558 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x4a3/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888036b7b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888036b7b800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888036b7b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888036b7b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888036b7b980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: a7 cmpsl %es:(%rdi),%ds:(%rsi) 1: 6c insb (%dx),%es:(%rdi) 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d 83 55 29 00 verw 0x295583(%rip) # 0x2955ab 28: fb sti 29: f4 hlt * 2a: e9 3c 0a 03 00 jmp 0x30a6b <-- trapping instruction 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop