==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline]
BUG: KASAN: use-after-free in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1817
Write of size 8 at addr ffff8881e72d31c8 by task syz-executor.0/382

CPU: 1 PID: 382 Comm: syz-executor.0 Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __hlist_del include/linux/list.h:791 [inline]
 detach_timer kernel/time/timer.c:824 [inline]
 expire_timers kernel/time/timer.c:1482 [inline]
 __run_timers+0x7be/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:538 [inline]
 smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:207 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp4+0x4/0x70 kernel/kcov.c:248
Code: 77 cf 89 f8 89 f6 48 c7 44 0a 08 02 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 c3 90 4c 8b 04 24 <65> 48 8b 05 24 50 9e 7e 65 8b 0d 29 50 9e 7e f7 c1 00 01 1f 00 74
RSP: 0018:ffff8881d7dbf760 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8881d7dbf8a8 RBX: 0000000000000004 RCX: ffff8881d9c18000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000004
RBP: 0000000000000040 R08: ffffffff8153b472 R09: ffff8881d7dbf810
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103afb7f15
R13: 0000000000000003 R14: dffffc0000000000 R15: 1ffff1103afb7f16
 stack_trace_consume_entry+0x162/0x240 kernel/stacktrace.c:94
 arch_stack_walk+0x105/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kfree+0x123/0x370 mm/slub.c:4071
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:884 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1042 [inline]
 do_ip6t_get_ctl+0x88c/0xb60 net/ipv6/netfilter/ip6_tables.c:1712
 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline]
 nf_getsockopt+0x28c/0x2b0 net/netfilter/nf_sockopt.c:122
 ipv6_getsockopt+0x1fe/0x300 net/ipv6/ipv6_sockglue.c:1410
 __sys_getsockopt+0x1c0/0x2b0 net/socket.c:2138
 __do_sys_getsockopt net/socket.c:2153 [inline]
 __se_sys_getsockopt net/socket.c:2150 [inline]
 __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2150
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f6629b5caca
Code: c4 c1 e0 1a 0d 00 00 04 00 89 01 e9 e0 fe ff ff e8 3b 05 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 b0 ff ff ff f7
RSP: 002b:00007ffe476ee5c8 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007ffe476ee650 RCX: 00007f6629b5caca
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffe476ee5ec R09: 0079746972756365
R10: 00007ffe476ee650 R11: 0000000000000212 R12: 00007f6629c61f80
R13: 00007ffe476ee5ec R14: 0000000000000000 R15: 00007f6629c62d00

Allocated by task 377:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
 kmem_cache_zalloc include/linux/slab.h:680 [inline]
 copy_signal+0x51/0x5d0 kernel/fork.c:1572
 copy_process+0x1265/0x3230 kernel/fork.c:2049
 _do_fork+0x197/0x900 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 10:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
 free_signal_struct kernel/fork.c:732 [inline]
 put_signal_struct kernel/fork.c:738 [inline]
 __put_task_struct+0x280/0x410 kernel/fork.c:752
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881e72d2f80
 which belongs to the cache signal_cache of size 1088
The buggy address is located 584 bytes inside of
 1088-byte region [ffff8881e72d2f80, ffff8881e72d33c0)
The buggy address belongs to the page:
page:ffffea00079cb400 refcount:1 mapcount:0 mapping:ffff8881f5cf8a00 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cf8a00
raw: 0000000000000000 00000000800d000d 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
 kmem_cache_zalloc include/linux/slab.h:680 [inline]
 copy_signal+0x51/0x5d0 kernel/fork.c:1572
 copy_process+0x1265/0x3230 kernel/fork.c:2049
 _do_fork+0x197/0x900 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 device_release+0x6b/0x190 drivers/base/core.c:1776
 kobject_cleanup lib/kobject.c:716 [inline]
 kobject_release lib/kobject.c:747 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e6/0x2f0 lib/kobject.c:764
 netdev_run_todo+0xc44/0xdf0 net/core/dev.c:9469
 tun_detach drivers/net/tun.c:766 [inline]
 tun_chr_close+0xc1/0x130 drivers/net/tun.c:3558
 __fput+0x262/0x680 fs/file_table.c:281
 task_work_run+0x140/0x170 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcaf/0x2bc0 kernel/exit.c:859
 do_group_exit+0x138/0x300 kernel/exit.c:982
 get_signal+0xdb1/0x1440 kernel/signal.c:2735
 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881e72d3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e72d3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e72d3180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8881e72d3200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e72d3280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1ef331067 P4D 1ef331067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 382 Comm: syz-executor.0 Tainted: G    B             5.4.274-syzkaller-00002-g6f97bd951d82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010206
RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881d9c18000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e72d31c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9f88
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e72d31c0
FS:  000055555737e480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d7d5a000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x879/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:538 [inline]
 smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:207 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp4+0x4/0x70 kernel/kcov.c:248
Code: 77 cf 89 f8 89 f6 48 c7 44 0a 08 02 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 c3 90 4c 8b 04 24 <65> 48 8b 05 24 50 9e 7e 65 8b 0d 29 50 9e 7e f7 c1 00 01 1f 00 74
RSP: 0018:ffff8881d7dbf760 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8881d7dbf8a8 RBX: 0000000000000004 RCX: ffff8881d9c18000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000004
RBP: 0000000000000040 R08: ffffffff8153b472 R09: ffff8881d7dbf810
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103afb7f15
R13: 0000000000000003 R14: dffffc0000000000 R15: 1ffff1103afb7f16
 stack_trace_consume_entry+0x162/0x240 kernel/stacktrace.c:94
 arch_stack_walk+0x105/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kfree+0x123/0x370 mm/slub.c:4071
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:884 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1042 [inline]
 do_ip6t_get_ctl+0x88c/0xb60 net/ipv6/netfilter/ip6_tables.c:1712
 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline]
 nf_getsockopt+0x28c/0x2b0 net/netfilter/nf_sockopt.c:122
 ipv6_getsockopt+0x1fe/0x300 net/ipv6/ipv6_sockglue.c:1410
 __sys_getsockopt+0x1c0/0x2b0 net/socket.c:2138
 __do_sys_getsockopt net/socket.c:2153 [inline]
 __se_sys_getsockopt net/socket.c:2150 [inline]
 __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2150
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f6629b5caca
Code: c4 c1 e0 1a 0d 00 00 04 00 89 01 e9 e0 fe ff ff e8 3b 05 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 b0 ff ff ff f7
RSP: 002b:00007ffe476ee5c8 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007ffe476ee650 RCX: 00007f6629b5caca
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffe476ee5ec R09: 0079746972756365
R10: 00007ffe476ee650 R11: 0000000000000212 R12: 00007f6629c61f80
R13: 00007ffe476ee5ec R14: 0000000000000000 R15: 00007f6629c62d00
Modules linked in:
CR2: 0000000000000000
---[ end trace 86246f6da24f392b ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010206
RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881d9c18000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e72d31c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9f88
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e72d31c0
FS:  000055555737e480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d7d5a000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	77 cf                	ja     0xffffffd1
   2:	89 f8                	mov    %edi,%eax
   4:	89 f6                	mov    %esi,%esi
   6:	48 c7 44 0a 08 02 00 	movq   $0x2,0x8(%rdx,%rcx,1)
   d:	00 00
   f:	48 89 44 0a 10       	mov    %rax,0x10(%rdx,%rcx,1)
  14:	48 89 74 0a 18       	mov    %rsi,0x18(%rdx,%rcx,1)
  19:	4c 89 44 0a 20       	mov    %r8,0x20(%rdx,%rcx,1)
  1e:	49 ff c1             	inc    %r9
  21:	4c 89 09             	mov    %r9,(%rcx)
  24:	c3                   	ret
  25:	90                   	nop
  26:	4c 8b 04 24          	mov    (%rsp),%r8
* 2a:	65 48 8b 05 24 50 9e 	mov    %gs:0x7e9e5024(%rip),%rax        # 0x7e9e5056 <-- trapping instruction
  31:	7e
  32:	65 8b 0d 29 50 9e 7e 	mov    %gs:0x7e9e5029(%rip),%ecx        # 0x7e9e5062
  39:	f7 c1 00 01 1f 00    	test   $0x1f0100,%ecx
  3f:	74                   	.byte 0x74