==================================================================
BUG: KASAN: slab-use-after-free in timer_is_static_object+0x35/0x80 kernel/time/timer.c:691
Read of size 8 at addr ffff888059c29898 by task syz.4.16153/8331
CPU: 1 UID: 0 PID: 8331 Comm: syz.4.16153 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
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+0x192/0x640 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/0x870 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
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 65 95 0b 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 e1 12 7a 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c6 7b 0e 0a cc 48 8d 3d 9e 51 73
RSP: 0000:ffffc900030b7818 EFLAGS: 00000286
RAX: b4addcabfd8d7000 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 000000003fd759c5 RSI: ffffffff8e161b73 RDI: ffffffff8c27aa00
RBP: 0000000000000000 R08: ffffffff823bf428 R09: ffffffff8e7602e0
R10: dffffc0000000000 R11: fffff94000364ca9 R12: 0000000000000002
R13: ffffffff8e7602e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
page_table_check_set+0x165/0x610 mm/page_table_check.c:112
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:413 [inline]
set_pte_range+0x84b/0x8a0 mm/memory.c:5526
filemap_map_order0_folio mm/filemap.c:3856 [inline]
filemap_map_pages+0xff2/0x2050 mm/filemap.c:3921
do_fault_around mm/memory.c:5756 [inline]
do_read_fault mm/memory.c:5789 [inline]
do_fault mm/memory.c:5932 [inline]
do_pte_missing+0x211a/0x3750 mm/memory.c:4477
handle_pte_fault mm/memory.c:6316 [inline]
__handle_mm_fault mm/memory.c:6454 [inline]
handle_mm_fault+0x1bec/0x3310 mm/memory.c:6623
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f321b455195
Code: ff 0f 1f 40 00 53 48 8b 1d 28 2c 3c 00 45 31 d2 31 c9 48 8b 17 45 31 db 4c 8d 83 00 00 40 00 48 89 d0 0f 1f 00 4c 39 c0 73 63 <44> 0f b6 08 48 83 c0 01 4c 89 ce 83 e6 7f 48 d3 e6 49 09 f2 45 84
RSP: 002b:00007ffeaf48ea60 EFLAGS: 00010287
RAX: 0000001b2fe20000 RBX: 0000001b2fe20000 RCX: 0000000000000000
RDX: 0000001b2fe20000 RSI: 00007ffeaf48ea50 RDI: 00007ffeaf48eb50
RBP: 00000000001a1633 R08: 0000001b30220000 R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 00000000001a1633 R15: 00007ffeaf48ed00
Allocated by task 31958:
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+0x31c/0x660 mm/slub.c:5339
kmalloc_noprof include/linux/slab.h:962 [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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 8303:
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:2687 [inline]
slab_free mm/slub.c:6124 [inline]
kfree+0x1c1/0x630 mm/slub.c:6442
rose_neigh_put include/net/rose.h:166 [inline]
rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
call_timer_fn+0x192/0x640 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/0x870 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 ffff888059c29800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 152 bytes inside of
freed 512-byte region [ffff888059c29800, ffff888059c29a00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x59c28
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 ffff88813fea8c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fea8c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001670a01 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 5822, tgid 5822 (syz-executor), ts 75306821269, free_ts 19521695871
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_slab_page mm/slub.c:3255 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3444
new_slab mm/slub.c:3502 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7134
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578
alloc_from_pcs mm/slub.c:4681 [inline]
slab_alloc_node mm/slub.c:4815 [inline]
__do_kmalloc_node mm/slub.c:5218 [inline]
__kmalloc_noprof+0x474/0x760 mm/slub.c:5231
kmalloc_noprof include/linux/slab.h:966 [inline]
kzalloc_noprof include/linux/slab.h:1200 [inline]
fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3819
ip6_route_add+0x49/0x1b0 net/ipv6/route.c:3948
addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2551
addrconf_add_dev net/ipv6/addrconf.c:2569 [inline]
addrconf_dev_config net/ipv6/addrconf.c:3483 [inline]
addrconf_init_auto_addrs+0x4d7/0xa50 net/ipv6/addrconf.c:3571
addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3744
notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
call_netdevice_notifiers net/core/dev.c:2301 [inline]
__dev_notify_flags+0x1a9/0x310 net/core/dev.c:9801
netif_change_flags+0xe8/0x1a0 net/core/dev.c:9830
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+0xc2b/0xdb0 mm/page_alloc.c:2978
__free_pages mm/page_alloc.c:5369 [inline]
free_contig_range+0xbb/0x170 mm/page_alloc.c:7373
destroy_args+0x4e5/0x570 mm/debug_vm_pgtable.c:993
debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1368
do_one_initcall+0x250/0x8d0 init/main.c:1382
do_initcall_level+0x104/0x190 init/main.c:1444
do_initcalls+0x59/0xa0 init/main.c:1460
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692
kernel_init+0x1d/0x1d0 init/main.c:1582
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888059c29780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888059c29800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888059c29880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888059c29900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888059c29980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: e9 30 ff ff ff jmp 0xffffff35
5: e8 65 95 0b 0a call 0xa0b956f
a: f7 c3 00 02 00 00 test $0x200,%ebx
10: 0f 84 38 ff ff ff je 0xffffff4e
16: 65 48 8b 05 e1 12 7a mov %gs:0x117a12e1(%rip),%rax # 0x117a12ff
1d: 11
1e: 48 3b 44 24 30 cmp 0x30(%rsp),%rax
23: 75 33 jne 0x58
25: fb sti
26: 48 83 c4 38 add $0x38,%rsp
* 2a: 5b pop %rbx <-- trapping instruction
2b: 41 5c pop %r12
2d: 41 5d pop %r13
2f: 41 5e pop %r14
31: 41 5f pop %r15
33: 5d pop %rbp
34: e9 c6 7b 0e 0a jmp 0xa0e7bff
39: cc int3
3a: 48 rex.W
3b: 8d .byte 0x8d
3c: 3d .byte 0x3d
3d: 9e sahf
3e: 51 push %rcx
3f: 73 .byte 0x73