==================================================================
BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88807953742a by task syz.0.687/7215

CPU: 0 PID: 7215 Comm: syz.0.687 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:ffffc900043978d8 EFLAGS: 00000206
RAX: ac38d9bd42d94f00 RBX: ffff88802a888000 RCX: ac38d9bd42d94f00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: 0000000000000000 R08: ffffc90004397b37 R09: ffffc90004397b00
R10: dffffc0000000000 R11: fffff52000872f67 R12: dffffc0000000000
R13: 0000000000000246 R14: ffffffff8c31eb00 R15: 00000000ffffffff
 lock_is_held include/linux/lockdep.h:287 [inline]
 ___might_sleep+0x9b/0x610 kernel/sched/core.c:9624
 __might_fault+0x6b/0x110 mm/memory.c:5354
 _copy_from_user+0x29/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user net/socket.c:2327 [inline]
 copy_msghdr_from_user net/socket.c:2378 [inline]
 recvmsg_copy_msghdr net/socket.c:2630 [inline]
 ___sys_recvmsg+0x173/0x5c0 net/socket.c:2702
 do_recvmmsg+0x382/0x850 net/socket.c:2800
 __sys_recvmmsg net/socket.c:2879 [inline]
 __do_sys_recvmmsg net/socket.c:2902 [inline]
 __se_sys_recvmmsg net/socket.c:2895 [inline]
 __x64_sys_recvmmsg+0x195/0x250 net/socket.c:2895
 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: 0033:0x7ff7faca2799
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:00007ff7f8edb028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007ff7faf1c090 RCX: 00007ff7faca2799
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007
RBP: 00007ff7fad38c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7faf1c128 R14: 00007ff7faf1c090 R15: 00007ffc22b25688
 </TASK>

Allocated by task 5254:
 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 ffff888079537400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 512-byte region [ffff888079537400, ffff888079537600)
The buggy address belongs to the page:
page:ffffea0001e54d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888079537400 pfn:0x79534
head:ffffea0001e54d00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000186cb08 ffffea000078f208 ffff888016c41c80
raw: ffff888079537400 0000000000100008 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4198, ts 61534919273, free_ts 61421947583
 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]
 __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 pskb_expand_head+0x127/0x10f0 net/core/skbuff.c:1709
 netlink_trim+0x180/0x220 net/netlink/af_netlink.c:1299
 netlink_broadcast_filtered+0x7c/0x1170 net/netlink/af_netlink.c:1511
 netlink_broadcast net/netlink/af_netlink.c:1556 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0xec/0x1a0 net/netlink/af_netlink.c:2550
 fib_table_insert+0xd36/0x1bb0 net/ipv4/fib_trie.c:1379
 fib_magic+0x2e1/0x3c0 net/ipv4/fib_frontend.c:1106
 fib_add_ifaddr+0x3f7/0x5e0 net/ipv4/fib_frontend.c:1150
 fib_netdev_event+0x35c/0x480 net/ipv4/fib_frontend.c:1488
 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
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_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x372/0xb50 net/netlink/af_netlink.c:2442
 netlink_rcv_skb+0x27a/0x440 net/netlink/af_netlink.c:2513
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080

Memory state around the buggy address:
 ffff888079537300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888079537380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888079537400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888079537480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888079537500: 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