==================================================================
BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
Read of size 2 at addr ffff888061baec2a by task syz-executor/4429

CPU: 1 PID: 4429 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x53a/0x7f0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 40 bb 10 0c 48 89 de 5b e9 77 3a 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 14 50 89 7e 65 8b 15 15 50 89 7e 81 e2 00
RSP: 0018:ffffc900022f78e0 EFLAGS: 00000246
RAX: ffffffff819e7cb6 RBX: ffffea00014c0140 RCX: ffff8880213ed940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900022f7b70 R08: ffffea00014c0177 R09: 1ffffd400029802e
R10: dffffc0000000000 R11: fffff9400029802f R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffea00017b4b48 R15: 000000000000000b
 _compound_head include/linux/page-flags.h:198 [inline]
 unlock_page+0x55/0x1f0 mm/filemap.c:1510
 shmem_undo_range+0x567/0x1930 mm/shmem.c:961
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
 evict+0x4c9/0x8d0 fs/inode.c:647
 do_unlinkat+0x3e7/0x710 fs/namei.c:4363
 __do_sys_unlink fs/namei.c:4404 [inline]
 __se_sys_unlink fs/namei.c:4402 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4402
 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: 0033:0x7f31ead60da7
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffdb302f1c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f31ead60da7
RDX: 00007ffdb302f1f0 RSI: 00007ffdb302f280 RDI: 00007ffdb302f280
RBP: 00007ffdb302f280 R08: 00007ffdb3030280 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdb3030310
R13: 00007f31eadcb71f R14: 000000000004bce3 R15: 00007ffdb3030350
 </TASK>

Allocated by task 7095:
 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_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 alloc_skb_with_frags+0xa7/0x730 net/core/skbuff.c:6170
 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2536
 __ip_append_data+0x2037/0x32d0 net/ipv4/ip_output.c:1102
 ip_make_skb+0x227/0x440 net/ipv4/ip_output.c:1648
 udp_sendmsg+0x1ab5/0x2370 net/ipv4/udp.c:1274
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmmsg+0x2ba/0x500 net/socket.c:2585
 __do_sys_sendmmsg net/socket.c:2614 [inline]
 __se_sys_sendmmsg net/socket.c:2611 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611
 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 ffff888061baec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 512-byte region [ffff888061baec00, ffff888061baee00)
The buggy address belongs to the page:
page:ffffea000186eb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888061baf000 pfn:0x61bac
head:ffffea000186eb00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000180a308 ffffea0000ae9808 ffff888016c41c80
raw: ffff888061baf000 000000000010000b 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 4189, ts 59613155041, free_ts 20908723793
 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:5487
 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]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 inet6_netconf_notify_devconf+0x10b/0x1d0 net/ipv6/addrconf.c:583
 __addrconf_sysctl_register+0x375/0x3e0 net/ipv6/addrconf.c:7113
 addrconf_sysctl_register+0x15c/0x1b0 net/ipv6/addrconf.c:7150
 ipv6_add_dev+0xbf3/0x1190 net/ipv6/addrconf.c:454
 addrconf_notify+0x66f/0xf00 net/ipv6/addrconf.c:3576
 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:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 register_netdevice+0x129d/0x16f0 net/core/dev.c:10428
 veth_newlink+0x8d7/0xe30 drivers/net/veth.c:1714
 __rtnl_newlink net/core/rtnetlink.c:3526 [inline]
 rtnl_newlink+0x1359/0x1a50 net/core/rtnetlink.c:3574
 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
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:9406
 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:
 ffff888061baeb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888061baeb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888061baec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888061baec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888061baed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   7:	00 00 00
   a:	53                   	push   %rbx
   b:	48 89 fb             	mov    %rdi,%rbx
   e:	e8 17 00 00 00       	call   0x2a
  13:	48 8b 3d 40 bb 10 0c 	mov    0xc10bb40(%rip),%rdi        # 0xc10bb5a
  1a:	48 89 de             	mov    %rbx,%rsi
  1d:	5b                   	pop    %rbx
  1e:	e9 77 3a 44 00       	jmp    0x443a9a
  23:	00 00                	add    %al,(%rax)
  25:	cc                   	int3
  26:	cc                   	int3
  27:	00 00                	add    %al,(%rax)
  29:	cc                   	int3
* 2a:	48 8b 04 24          	mov    (%rsp),%rax <-- trapping instruction
  2e:	65 48 8b 0d 14 50 89 	mov    %gs:0x7e895014(%rip),%rcx        # 0x7e89504a
  35:	7e
  36:	65 8b 15 15 50 89 7e 	mov    %gs:0x7e895015(%rip),%edx        # 0x7e895052
  3d:	81                   	.byte 0x81
  3e:	e2 00                	loop   0x40