==================================================================
BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88805ff8e82a by task syz.1.1262/8617

CPU: 1 PID: 8617 Comm: syz.1.1262 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5671
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900033af678 EFLAGS: 00000206
RAX: 2f0fb75706166600 RBX: ffff88807cdad940 RCX: 2f0fb75706166600
RDX: 0000000000000002 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: 0000000000000001 R08: ffffea000178aff7 R09: 1ffffd40002f15fe
R10: dffffc0000000000 R11: fffff940002f15ff R12: 0000000000000001
R13: 0000000000000246 R14: ffffffff8c31eaa0 R15: ffff88807cdae458
 xa_entry include/linux/xarray.h:1197 [inline]
 xas_reload+0x19c/0x470 include/linux/xarray.h:1573
 next_uptodate_page+0x2a5/0x8b0 mm/filemap.c:3259
 next_map_page mm/filemap.c:3296 [inline]
 filemap_map_pages+0xee0/0x13b0 mm/filemap.c:3352
 do_fault_around mm/memory.c:4243 [inline]
 do_read_fault mm/memory.c:4258 [inline]
 do_fault mm/memory.c:4392 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x25bc/0x4410 mm/memory.c:4883
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x94b/0x11e0 mm/gup.c:1197
 populate_vma_page_range+0x213/0x290 mm/gup.c:1529
 __mm_populate+0x275/0x3b0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2646 [inline]
 vm_mmap_pgoff+0x212/0x2d0 mm/util.c:556
 ksys_mmap_pgoff+0x140/0x790 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff4421e3799
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:00007ff44043d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff44245cfa0 RCX: 00007ff4421e3799
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007ff442279c99 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff44245d038 R14: 00007ff44245cfa0 R15: 00007ffe139fde98
 </TASK>

Allocated by task 6639:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 rose_add_node+0x227/0xdb0 net/rose/rose_route.c:85
 rose_rt_ioctl+0xa2b/0xe70 net/rose/rose_route.c:738
 rose_ioctl+0x2a7/0x7d0 net/rose/af_rose.c:1372
 sock_do_ioctl+0xfb/0x320 net/socket.c:1147
 sock_ioctl+0x4d2/0x710 net/socket.c:1266
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88805ff8e800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 512-byte region [ffff88805ff8e800, ffff88805ff8ea00)
The buggy address belongs to the page:
page:ffffea00017fe300 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805ff8d000 pfn:0x5ff8c
head:ffffea00017fe300 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001834b08 ffffea000181ed08 ffff888016c41c80
raw: ffff88805ff8d000 0000000000100003 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4186, ts 68338032335, free_ts 23617796445
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 __kmalloc+0x1cd/0x330 mm/slub.c:4408
 kmalloc include/linux/slab.h:612 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x44f/0x1210 net/ipv6/route.c:3769
 ip6_route_add+0x24/0x130 net/ipv6/route.c:3865
 addrconf_add_mroute net/ipv6/addrconf.c:2510 [inline]
 addrconf_add_dev+0x295/0x3c0 net/ipv6/addrconf.c:2528
 addrconf_dev_config net/ipv6/addrconf.c:3405 [inline]
 addrconf_init_auto_addrs+0x6a0/0xb00 net/ipv6/addrconf.c:3493
 addrconf_notify+0xa6b/0xf00 net/ipv6/addrconf.c:3662
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
 call_netdevice_notifiers net/core/dev.c:2088 [inline]
 __dev_notify_flags+0x194/0x300 net/core/dev.c:8917
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8955
 do_setlink+0xcdb/0x3d60 net/core/rtnetlink.c:2781
 __rtnl_newlink net/core/rtnetlink.c:3452 [inline]
 rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3574
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9428
 destroy_args+0xf0/0xa00 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336
 do_one_initcall+0x272/0x730 init/main.c:1316
 do_initcall_level+0x137/0x1f0 init/main.c:1389
 do_initcalls+0x4b/0x90 init/main.c:1405
 kernel_init_freeable+0x3e9/0x570 init/main.c:1629
 kernel_init+0x19/0x1b0 init/main.c:1520
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff88805ff8e700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805ff8e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805ff8e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88805ff8e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805ff8e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	75 40                	jne    0x42
   2:	48 c7 04 24 00 00 00 	movq   $0x0,(%rsp)
   9:	00
   a:	9c                   	pushf
   b:	8f 04 24             	pop    (%rsp)
   e:	f7 04 24 00 02 00 00 	testl  $0x200,(%rsp)
  15:	75 46                	jne    0x5d
  17:	41 f7 c5 00 02 00 00 	test   $0x200,%r13d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  28:	00 00
* 2a:	48 3b 44 24 08       	cmp    0x8(%rsp),%rax <-- trapping instruction
  2f:	75 3c                	jne    0x6d
  31:	89 e8                	mov    %ebp,%eax
  33:	48 83 c4 10          	add    $0x10,%rsp
  37:	5b                   	pop    %rbx
  38:	41 5c                	pop    %r12
  3a:	41 5d                	pop    %r13
  3c:	41 5e                	pop    %r14
  3e:	41 5f                	pop    %r15