==================================================================
BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88806d279c2a by task kworker/u8:0/13799

CPU: 1 UID: 0 PID: 13799 Comm: kworker/u8:0 Not tainted 6.15.0-rc5-syzkaller-01021-g0b28182c73a3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers kernel/time/timer.c:2414 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2426
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 do_softirq+0xec/0x180 kernel/softirq.c:480
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
 unregister_netdevice_many_notify+0x1685/0x2320 net/core/dev.c:12035
 unregister_netdevice_many net/core/dev.c:12087 [inline]
 default_device_exit_batch+0x819/0x890 net/core/dev.c:12591
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x522/0x990 net/core/net_namespace.c:253
 cleanup_net+0x4c5/0x8a0 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 17494:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x147/0xa70 net/ipv6/route.c:3782
 ip6_route_add+0x29/0x2f0 net/ipv6/route.c:3909
 addrconf_add_mroute net/ipv6/addrconf.c:2551 [inline]
 addrconf_add_dev+0x24f/0x340 net/ipv6/addrconf.c:2569
 inet6_addr_add+0x1a1/0xc00 net/ipv6/addrconf.c:3031
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 17704:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x193/0x440 mm/slub.c:4841
 rcu_do_batch kernel/rcu/tree.c:2568 [inline]
 rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2824
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3082 [inline]
 call_rcu+0x142/0x990 kernel/rcu/tree.c:3202
 call_rcu_hurry include/linux/rcupdate.h:115 [inline]
 fib6_info_release include/net/ip6_fib.h:344 [inline]
 ip6_route_info_create_nh+0x1e8/0x870 net/ipv6/route.c:3895
 ip6_route_add+0xf6/0x2f0 net/ipv6/route.c:3915
 addrconf_add_mroute net/ipv6/addrconf.c:2551 [inline]
 addrconf_add_dev+0x24f/0x340 net/ipv6/addrconf.c:2569
 inet6_addr_add+0x1a1/0xc00 net/ipv6/addrconf.c:3031
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88806d279c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88806d279c00, ffff88806d279e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6d278
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 ffff88801a041c80 ffffea00009f5800 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a041c80 ffffea00009f5800 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001b49e01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5835, tgid 5835 (syz-executor), ts 85686109963, free_ts 85568770267
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x147/0xa70 net/ipv6/route.c:3782
 ip6_route_add+0x29/0x2f0 net/ipv6/route.c:3909
 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
 fixup_permanent_addr net/ipv6/addrconf.c:3602 [inline]
 addrconf_permanent_addr+0x67f/0x9d0 net/ipv6/addrconf.c:3626
 addrconf_notify+0x887/0x1010 net/ipv6/addrconf.c:3698
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline]
 call_netdevice_notifiers net/core/dev.c:2280 [inline]
 __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9477
 do_setlink+0xcb9/0x40d0 net/core/rtnetlink.c:3152
page last free pid 5835 tgid 5835 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0xb14/0xce0 mm/page_alloc.c:2721
 __slab_free+0x326/0x400 mm/slub.c:4553
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_node_noprof+0x21b/0x4e0 mm/slub.c:4333
 kmalloc_node_noprof include/linux/slab.h:932 [inline]
 qdisc_alloc+0x97/0xaa0 net/sched/sch_generic.c:948
 qdisc_create_dflt+0x8e/0x4e0 net/sched/sch_generic.c:1010
 attach_one_default_qdisc net/sched/sch_generic.c:1176 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2649 [inline]
 attach_default_qdiscs net/sched/sch_generic.c:1194 [inline]
 dev_activate+0x378/0x1150 net/sched/sch_generic.c:1253
 __dev_open+0x69c/0x880 net/core/dev.c:1690
 __dev_change_flags+0x1ea/0x6d0 net/core/dev.c:9409
 netif_change_flags+0x88/0x1a0 net/core/dev.c:9472
 do_setlink+0xcb9/0x40d0 net/core/rtnetlink.c:3152
 rtnl_changelink net/core/rtnetlink.c:3770 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3929 [inline]
 rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4066
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534

Memory state around the buggy address:
 ffff88806d279b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806d279b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806d279c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88806d279c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806d279d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================