==================================================================
BUG: KASAN: slab-use-after-free in timer_is_static_object+0x35/0x80 kernel/time/timer.c:691
Read of size 8 at addr ffff888057fd0098 by task syz.1.2702/14277

CPU: 1 UID: 0 PID: 14277 Comm: syz.1.2702 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 timer_is_static_object+0x35/0x80 kernel/time/timer.c:691
 lookup_object_or_alloc lib/debugobjects.c:679 [inline]
 debug_object_activate+0x141/0x580 lib/debugobjects.c:820
 debug_timer_activate kernel/time/timer.c:793 [inline]
 __mod_timer+0xa4f/0xf30 kernel/time/timer.c:1124
 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x97/0x2c0 mm/kasan/generic.c:200
Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 9e 01 00 00 49 ff c3 48 ff c3 75 ee e9 1d 01 00 00 44 89 dd
RSP: 0018:ffffc9001c1e74f0 EFLAGS: 00000246
RAX: ffffffff81fb9601 RBX: ffffffffffffffff RCX: ffffffff81fb969b
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0001b090b4
RBP: 0000000000000001 R08: ffffea0001b090b7 R09: 1ffffd4000361216
R10: dffffc0000000000 R11: fffff94000361216 R12: 0000000000000001
R13: dffffc0000000000 R14: fffff94000361217 R15: 1ffffd4000361216
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_add_unless include/linux/atomic/atomic-instrumented.h:1517 [inline]
 page_ref_add_unless include/linux/page_ref.h:238 [inline]
 folio_ref_add_unless include/linux/page_ref.h:248 [inline]
 folio_try_get+0xdb/0x340 include/linux/page_ref.h:264
 next_uptodate_folio+0xcb/0x5d0 mm/filemap.c:3709
 filemap_map_pages+0x14fc/0x2000 mm/filemap.c:3929
 do_fault_around mm/memory.c:5716 [inline]
 do_read_fault mm/memory.c:5749 [inline]
 do_fault mm/memory.c:5892 [inline]
 do_pte_missing+0x20b0/0x3310 mm/memory.c:4404
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x1b8c/0x32a0 mm/memory.c:6583
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x165b/0x29d0 mm/gup.c:1428
 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
 __mm_populate+0x25f/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:3705 [inline]
 vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe4c119acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe4c1fd2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fe4c1415fa0 RCX: 00007fe4c119acb9
RDX: 0000000000000005 RSI: 0000000000c00000 RDI: 0000200000001000
RBP: 00007fe4c1208bf7 R08: ffffffffffffffff R09: 0000000000000000
R10: 000000000003b071 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4c1416038 R14: 00007fe4c1415fa0 R15: 00007fff5ff690c8
 </TASK>

Allocated by task 6188:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780
 kmalloc_noprof include/linux/slab.h:957 [inline]
 rose_add_node+0x23c/0xf00 net/rose/rose_route.c:85
 rose_rt_ioctl+0xd35/0x12a0 net/rose/rose_route.c:748
 rose_ioctl+0x3fb/0x8f0 net/rose/af_rose.c:1382
 sock_do_ioctl+0x101/0x320 net/socket.c:1254
 sock_ioctl+0x5c6/0x7f0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 14259:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6674 [inline]
 kfree+0x1be/0x650 mm/slub.c:6882
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888057fd0000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 152 bytes inside of
 freed 512-byte region [ffff888057fd0000, ffff888057fd0200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57fd0
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 ffff88813ff26c80 ffffea0000ccad00 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff26c80 ffffea0000ccad00 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015ff401 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5110, tgid 5110 (kworker/u8:14), ts 74905067352, free_ts 21475223859
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3a0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xd82/0x1760 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_noprof+0x46c/0x7e0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3817
 addrconf_f6i_alloc+0x200/0x490 net/ipv6/route.c:4686
 ipv6_add_addr+0x59c/0x10d0 net/ipv6/addrconf.c:1126
 addrconf_add_linklocal+0x276/0x6d0 net/ipv6/addrconf.c:3311
 addrconf_addr_gen+0x4f2/0x610 net/ipv6/addrconf.c:3442
 addrconf_init_auto_addrs+0x641/0xa80 net/ipv6/addrconf.c:-1
 addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3740
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xbb0/0xd10 mm/page_alloc.c:2973
 __free_pages mm/page_alloc.c:5359 [inline]
 free_contig_range+0x1bd/0x480 mm/page_alloc.c:7236
 destroy_args+0x69/0x630 mm/debug_vm_pgtable.c:983
 debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1372
 do_one_initcall+0x250/0x840 init/main.c:1378
 do_initcall_level+0x104/0x190 init/main.c:1440
 do_initcalls+0x59/0xa0 init/main.c:1456
 kernel_init_freeable+0x2a6/0x3d0 init/main.c:1688
 kernel_init+0x1d/0x1d0 init/main.c:1578
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff888057fcff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888057fd0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888057fd0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888057fd0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888057fd0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	00 fc                	add    %bh,%ah
   2:	ff                   	lcall  (bad)
   3:	df 4d 8d             	fisttps -0x73(%rbp)
   6:	34 19                	xor    $0x19,%al
   8:	4d 89 f4             	mov    %r14,%r12
   b:	4d 29 dc             	sub    %r11,%r12
   e:	49 83 fc 10          	cmp    $0x10,%r12
  12:	7f 29                	jg     0x3d
  14:	4d 85 e4             	test   %r12,%r12
  17:	0f 84 3d 01 00 00    	je     0x15a
  1d:	4c 89 cb             	mov    %r9,%rbx
  20:	48 f7 d3             	not    %rbx
  23:	4c 01 fb             	add    %r15,%rbx
  26:	41 80 3b 00          	cmpb   $0x0,(%r11)
* 2a:	0f 85 9e 01 00 00    	jne    0x1ce <-- trapping instruction
  30:	49 ff c3             	inc    %r11
  33:	48 ff c3             	inc    %rbx
  36:	75 ee                	jne    0x26
  38:	e9 1d 01 00 00       	jmp    0x15a
  3d:	44 89 dd             	mov    %r11d,%ebp