==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881e892f1c8 by task syz.2.381/1789

CPU: 0 PID: 1789 Comm: syz.2.381 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
 __kasan_report+0xef/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137
 hlist_add_head include/linux/list.h:814 [inline]
 enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
 __internal_add_timer kernel/time/timer.c:554 [inline]
 internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604
 __mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065
 mod_timer+0x1f/0x30 kernel/time/timer.c:1117
 can_stat_update+0xbab/0xc40 net/can/proc.c:186
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x197/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:180
Code: c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 be 0c 00 00 00 48 c7 c7 00 96 d1 85 e8 6b f2 2d 00 5d c3 00 00 90 90 00 00 90 90 00 <55> 48 89 e5 48 8b 45 08 65 48 8b 0d 90 0e a3 7e 65 8b 15 95 0e a3
RSP: 0018:ffff8881e284f5d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff817c4e5a RBX: ffffea0007a152c8 RCX: 0000000000000000
RDX: ffff8881e681bf00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881e284f610 R08: dffffc0000000000 R09: ffffed103cd037e1
R10: ffffed103cd037e1 R11: 1ffff1103cd037e0 R12: ffffea00079b5ec0
R13: dffffc0000000000 R14: ffffea00079b5ec8 R15: 0000000000000000
 zap_pte_range mm/memory.c:1102 [inline]
 zap_pmd_range mm/memory.c:1222 [inline]
 zap_pud_range mm/memory.c:1251 [inline]
 zap_p4d_range mm/memory.c:1272 [inline]
 unmap_page_range+0x105b/0x1b20 mm/memory.c:1293
 unmap_single_vma mm/memory.c:1338 [inline]
 unmap_vmas+0x245/0x340 mm/memory.c:1370
 exit_mmap+0x2bb/0x520 mm/mmap.c:3191
 __mmput+0x92/0x2e0 kernel/fork.c:1101
 mmput+0x47/0x60 kernel/fork.c:1122
 exit_mm kernel/exit.c:538 [inline]
 do_exit+0x99f/0x2660 kernel/exit.c:848
 do_group_exit+0x13e/0x300 kernel/exit.c:984
 get_signal+0xdee/0x13d0 kernel/signal.c:2738
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f42fca50969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f42fb0b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffff5 RBX: 00007f42fcc77fa0 RCX: 00007f42fca50969
RDX: 0000000000000080 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f42fcad2ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f42fcc77fa0 R15: 00007ffd861b7d78

Allocated by task 338:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543
 __kmalloc+0x12a/0x2f0 mm/slub.c:3913
 kmalloc include/linux/slab.h:561 [inline]
 context_struct_to_string+0x441/0x840 security/selinux/ss/services.c:1242
 security_sid_to_context_core+0x25c/0x380 security/selinux/ss/services.c:1339
 security_sid_to_context_force+0x36/0x40 security/selinux/ss/services.c:1368
 selinux_inode_init_security+0x671/0x950 security/selinux/hooks.c:2957
 security_inode_init_security+0x14e/0x370 security/security.c:998
 shmem_symlink+0xd0/0x4d0 mm/shmem.c:3073
 vfs_symlink+0x337/0x4c0 fs/namei.c:4276
 do_symlinkat+0x103/0x3b0 fs/namei.c:4303
 __do_sys_symlink fs/namei.c:4322 [inline]
 __se_sys_symlink fs/namei.c:4320 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4320
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 338:
 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+0x1c3/0x280 mm/kasan/common.c:487
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
 slab_free mm/slub.c:3080 [inline]
 kfree+0xbe/0x260 mm/slub.c:4071
 security_inode_init_security+0x264/0x370 security/security.c:1012
 shmem_symlink+0xd0/0x4d0 mm/shmem.c:3073
 vfs_symlink+0x337/0x4c0 fs/namei.c:4276
 do_symlinkat+0x103/0x3b0 fs/namei.c:4303
 __do_sys_symlink fs/namei.c:4322 [inline]
 __se_sys_symlink fs/namei.c:4320 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4320
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881e892f1c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8881e892f1c0, ffff8881e892f1e0)
The buggy address belongs to the page:
page:ffffea0007a24bc0 refcount:1 mapcount:0 mapping:ffff8881f5c03400 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f5c03400
raw: 0000000000000000 0000000000400040 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 __kmalloc+0x176/0x2f0 mm/slub.c:3909
 kmalloc include/linux/slab.h:561 [inline]
 context_struct_to_string+0x441/0x840 security/selinux/ss/services.c:1242
 security_sid_to_context_core+0x25c/0x380 security/selinux/ss/services.c:1339
 security_sid_to_context_force+0x36/0x40 security/selinux/ss/services.c:1368
 selinux_inode_init_security+0x671/0x950 security/selinux/hooks.c:2957
 security_inode_init_security+0x14e/0x370 security/security.c:998
 shmem_mknod+0xbb/0x1c0 mm/shmem.c:2849
 shmem_create+0x2b/0x40 mm/shmem.c:2904
 lookup_open fs/namei.c:3379 [inline]
 do_last fs/namei.c:3471 [inline]
 path_openat+0x1603/0x35c0 fs/namei.c:3683
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_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x2a9/0x3a0 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4954 [inline]
 __free_pages mm/page_alloc.c:4962 [inline]
 free_pages+0x117/0x180 mm/page_alloc.c:4970
 tlb_batch_list_free mm/mmu_gather.c:61 [inline]
 tlb_finish_mmu+0x248/0x300 mm/mmu_gather.c:280
 exit_mmap+0x2db/0x520 mm/mmap.c:3193
 __mmput+0x92/0x2e0 kernel/fork.c:1101
 mmput+0x47/0x60 kernel/fork.c:1122
 exit_mm kernel/exit.c:538 [inline]
 do_exit+0x99f/0x2660 kernel/exit.c:848
 do_group_exit+0x13e/0x300 kernel/exit.c:984
 get_signal+0xdee/0x13d0 kernel/signal.c:2738
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881e892f080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881e892f100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8881e892f180: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                                              ^
 ffff8881e892f200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881e892f280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000074
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1d9f52067 P4D 1d9f52067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1789 Comm: syz.2.381 Tainted: G    B             5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x74
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881e681bf00
RDX: 0000000000000101 RSI: 0000000000000074 RDI: ffff8881e892f1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa180
R13: dffffc0000000000 R14: 0000000000000074 R15: ffff8881e892f1c0
FS:  00007f42fb0b96c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000004a CR3: 00000001ea9ba000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x197/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:page_mapcount include/linux/mm.h:824 [inline]
RIP: 0010:zap_pte_range mm/memory.c:1106 [inline]
RIP: 0010:zap_pmd_range mm/memory.c:1222 [inline]
RIP: 0010:zap_pud_range mm/memory.c:1251 [inline]
RIP: 0010:zap_p4d_range mm/memory.c:1272 [inline]
RIP: 0010:unmap_page_range+0xeed/0x1b20 mm/memory.c:1293
Code: da ff b8 00 00 01 00 49 21 c7 75 67 43 80 3c 26 00 4c 8b 7c 24 20 74 08 48 89 df e8 9d d9 08 00 48 8b 1b 48 89 de 48 83 e6 01 <31> ff e8 2c e3 da ff 48 83 e3 01 4c 8b 74 24 08 0f 85 66 06 00 00
RSP: 0018:ffff8881e284f620 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000010000 RBX: ffffea00079b9408 RCX: 0000000000000000
RDX: ffff8881e681bf00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8881e284f770 R08: dffffc0000000000 R09: fffff94000f61e51
R10: fffff94000f61e51 R11: 1ffffd4000f61e50 R12: dffffc0000000000
R13: ffffea0007b0f280 R14: 1ffffd4000f61e51 R15: ffff8881e52613b0
 unmap_single_vma mm/memory.c:1338 [inline]
 unmap_vmas+0x245/0x340 mm/memory.c:1370
 exit_mmap+0x2bb/0x520 mm/mmap.c:3191
 __mmput+0x92/0x2e0 kernel/fork.c:1101
 mmput+0x47/0x60 kernel/fork.c:1122
 exit_mm kernel/exit.c:538 [inline]
 do_exit+0x99f/0x2660 kernel/exit.c:848
 do_group_exit+0x13e/0x300 kernel/exit.c:984
 get_signal+0xdee/0x13d0 kernel/signal.c:2738
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f42fca50969
Code: Bad RIP value.
RSP: 002b:00007f42fb0b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffff5 RBX: 00007f42fcc77fa0 RCX: 00007f42fca50969
RDX: 0000000000000080 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f42fcad2ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f42fcc77fa0 R15: 00007ffd861b7d78
Modules linked in:
CR2: 0000000000000074
---[ end trace 3278447f3b5505af ]---
RIP: 0010:0x74
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881e681bf00
RDX: 0000000000000101 RSI: 0000000000000074 RDI: ffff8881e892f1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa180
R13: dffffc0000000000 R14: 0000000000000074 R15: ffff8881e892f1c0
FS:  00007f42fb0b96c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000004a CR3: 00000001ea9ba000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	b8 00 00 01 00       	mov    $0x10000,%eax
   5:	49 21 c7             	and    %rax,%r15
   8:	75 67                	jne    0x71
   a:	43 80 3c 26 00       	cmpb   $0x0,(%r14,%r12,1)
   f:	4c 8b 7c 24 20       	mov    0x20(%rsp),%r15
  14:	74 08                	je     0x1e
  16:	48 89 df             	mov    %rbx,%rdi
  19:	e8 9d d9 08 00       	call   0x8d9bb
  1e:	48 8b 1b             	mov    (%rbx),%rbx
  21:	48 89 de             	mov    %rbx,%rsi
  24:	48 83 e6 01          	and    $0x1,%rsi
* 28:	31 ff                	xor    %edi,%edi <-- trapping instruction
  2a:	e8 2c e3 da ff       	call   0xffdae35b
  2f:	48 83 e3 01          	and    $0x1,%rbx
  33:	4c 8b 74 24 08       	mov    0x8(%rsp),%r14
  38:	0f 85 66 06 00 00    	jne    0x6a4