==================================================================
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 ffff8881e861b1c8 by task syz.4.117/847

CPU: 0 PID: 847 Comm: syz.4.117 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:539 [inline]
 smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:deref_stack_reg+0x181/0x1f0 arch/x86/kernel/unwind_orc.c:350
Code: e8 24 09 00 00 42 80 3c 23 00 74 08 4c 89 f7 e8 c5 56 64 00 4c 8b 74 24 40 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 25 57 64 00 4c 89 33 b0 01 48 c7 44 24 20 0e 36
RSP: 0018:ffff8881d8ef5f40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff1103b1dec68 RBX: ffff8881d8ef6340 RCX: dffffc0000000000
RDX: ffff8881d8ef6340 RSI: ffff8881d8ef5f80 RDI: ffff8881d8ef6db0
RBP: ffff8881d8ef5ff0 R08: dffffc0000000000 R09: ffff8881d8ef6350
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff1103b1debec R14: ffff8881d8ef6fc0 R15: ffff8881d8ef6db0
 unwind_next_frame+0x1681/0x1ea0 arch/x86/kernel/unwind_orc.c:579
 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 save_stack+0x95/0x880 mm/page_owner.c:122
 __set_page_owner+0x33/0x1e0 mm/page_owner.c:191
 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_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 shmem_alloc_page mm/shmem.c:1503 [inline]
 shmem_alloc_and_acct_page+0x492/0x9d0 mm/shmem.c:1528
 shmem_getpage_gfp+0xf5d/0x2440 mm/shmem.c:1852
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0xc9/0x1a0 mm/shmem.c:2447
 generic_perform_write+0x2c7/0x560 mm/filemap.c:3450
 __generic_file_write_iter+0x224/0x530 mm/filemap.c:3579
 generic_file_write_iter+0x455/0x5f0 mm/filemap.c:3611
 call_write_iter include/linux/fs.h:1991 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x5d3/0x750 fs/read_write.c:496
 __kernel_write+0x10f/0x350 fs/read_write.c:515
 dump_emit+0x213/0x350 fs/coredump.c:838
 elf_core_dump+0x3e1b/0x4740 fs/binfmt_elf.c:2352
 do_coredump+0x20fb/0x2f00 fs/coredump.c:801
 get_signal+0xd83/0x1440 kernel/signal.c:2732
 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
 ret_from_intr+0x1c/0x1c
RIP: 0033:0x7f07eaf64757
Code: 88 15 a2 6f e8 00 88 05 9f 6f e8 00 c3 50 48 8d 35 58 fb 1b 00 48 8d 3d 5e fb 1b 00 31 c0 e8 30 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8
RSP: 002b:00007f07e96ee120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f07eb0a3169
RDX: 00007f07e96ee140 RSI: 00007f07e96ee270 RDI: 000000000000000b
RBP: 00007f07eb1242a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f07eb2bbfa0 R15: 00007ffdb05cf3e8

The buggy address belongs to the page:
page:ffffea0007a186c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea000791b608 ffffea0007a18688 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102cc2(GFP_HIGHUSER|__GFP_NOWARN)
 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_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 pcpu_alloc_pages mm/percpu-vm.c:94 [inline]
 pcpu_populate_chunk+0x1bb/0xd00 mm/percpu-vm.c:284
 pcpu_alloc+0x79e/0x1050 mm/percpu.c:1714
 prealloc_init+0x238/0x800 kernel/bpf/hashtab.c:154
 htab_map_alloc+0x638/0x930 kernel/bpf/hashtab.c:385
 find_and_alloc_map kernel/bpf/syscall.c:122 [inline]
 map_create kernel/bpf/syscall.c:573 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
 __se_sys_bpf+0x3291/0xbcb0 kernel/bpf/syscall.c:2849
 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_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4953 [inline]
 __free_pages+0xaf/0x140 mm/page_alloc.c:4961
 pcpu_free_pages mm/percpu-vm.c:64 [inline]
 pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
 pcpu_balance_workfn+0x940/0x1450 mm/percpu.c:1865
 process_one_work+0x765/0xd20 kernel/workqueue.c:2290
 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Memory state around the buggy address:
 ffff8881e861b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881e861b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881e861b180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881e861b200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881e861b280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1e1e33067 P4D 1e1e33067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 847 Comm: syz.4.117 Tainted: G    B             5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881e1c78fc0
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e861b1c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9ec8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e861b1c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d879b000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
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:539 [inline]
 smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:deref_stack_reg+0x181/0x1f0 arch/x86/kernel/unwind_orc.c:350
Code: e8 24 09 00 00 42 80 3c 23 00 74 08 4c 89 f7 e8 c5 56 64 00 4c 8b 74 24 40 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 25 57 64 00 4c 89 33 b0 01 48 c7 44 24 20 0e 36
RSP: 0018:ffff8881d8ef5f40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff1103b1dec68 RBX: ffff8881d8ef6340 RCX: dffffc0000000000
RDX: ffff8881d8ef6340 RSI: ffff8881d8ef5f80 RDI: ffff8881d8ef6db0
RBP: ffff8881d8ef5ff0 R08: dffffc0000000000 R09: ffff8881d8ef6350
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff1103b1debec R14: ffff8881d8ef6fc0 R15: ffff8881d8ef6db0
 unwind_next_frame+0x1681/0x1ea0 arch/x86/kernel/unwind_orc.c:579
 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 save_stack+0x95/0x880 mm/page_owner.c:122
 __set_page_owner+0x33/0x1e0 mm/page_owner.c:191
 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_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 shmem_alloc_page mm/shmem.c:1503 [inline]
 shmem_alloc_and_acct_page+0x492/0x9d0 mm/shmem.c:1528
 shmem_getpage_gfp+0xf5d/0x2440 mm/shmem.c:1852
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0xc9/0x1a0 mm/shmem.c:2447
 generic_perform_write+0x2c7/0x560 mm/filemap.c:3450
 __generic_file_write_iter+0x224/0x530 mm/filemap.c:3579
 generic_file_write_iter+0x455/0x5f0 mm/filemap.c:3611
 call_write_iter include/linux/fs.h:1991 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x5d3/0x750 fs/read_write.c:496
 __kernel_write+0x10f/0x350 fs/read_write.c:515
 dump_emit+0x213/0x350 fs/coredump.c:838
 elf_core_dump+0x3e1b/0x4740 fs/binfmt_elf.c:2352
 do_coredump+0x20fb/0x2f00 fs/coredump.c:801
 get_signal+0xd83/0x1440 kernel/signal.c:2732
 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
 ret_from_intr+0x1c/0x1c
RIP: 0033:0x7f07eaf64757
Code: 88 15 a2 6f e8 00 88 05 9f 6f e8 00 c3 50 48 8d 35 58 fb 1b 00 48 8d 3d 5e fb 1b 00 31 c0 e8 30 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8
RSP: 002b:00007f07e96ee120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f07eb0a3169
RDX: 00007f07e96ee140 RSI: 00007f07e96ee270 RDI: 000000000000000b
RBP: 00007f07eb1242a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f07eb2bbfa0 R15: 00007ffdb05cf3e8
Modules linked in:
CR2: 0000000000000000
---[ end trace 256fa75e89605398 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202
RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881e1c78fc0
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e861b1c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff9ec8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e861b1c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d879b000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	e8 24 09 00 00       	call   0x929
   5:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 c5 56 64 00       	call   0x6456d9
  14:	4c 8b 74 24 40       	mov    0x40(%rsp),%r14
  19:	48 8b 5c 24 18       	mov    0x18(%rsp),%rbx
  1e:	48 89 d8             	mov    %rbx,%rax
  21:	48 c1 e8 03          	shr    $0x3,%rax
  25:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
* 2a:	74 08                	je     0x34 <-- trapping instruction
  2c:	48 89 df             	mov    %rbx,%rdi
  2f:	e8 25 57 64 00       	call   0x645759
  34:	4c 89 33             	mov    %r14,(%rbx)
  37:	b0 01                	mov    $0x1,%al
  39:	48                   	rex.W
  3a:	c7                   	.byte 0xc7
  3b:	44 24 20             	rex.R and $0x20,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss