================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x253/0x260 kernel/workqueue.c:4124 Read of size 4 at addr ffff88801c0561c0 by task pool_workqueue_/3 CPU: 0 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc4-syzkaller-00284-gb9ddbb0cde2a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x175/0x1b0 mm/kasan/report.c:588 pwq_release_workfn+0x253/0x260 kernel/workqueue.c:4124 kthread_worker_fn+0x4ba/0xa90 kernel/kthread.c:823 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 12913: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] alloc_workqueue+0x172/0x1520 kernel/workqueue.c:4684 wg_newlink+0x34e/0x710 drivers/net/wireguard/device.c:343 rtnl_newlink_create net/core/rtnetlink.c:3485 [inline] __rtnl_newlink net/core/rtnetlink.c:3705 [inline] rtnl_newlink+0x1579/0x2070 net/core/rtnetlink.c:3718 rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x7dc/0x970 net/netlink/af_netlink.c:1368 netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2558 ___sys_sendmsg net/socket.c:2612 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 12913: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0x25f/0x3b0 mm/slub.c:3822 alloc_workqueue+0xeba/0x1520 kernel/workqueue.c:4746 wg_newlink+0x34e/0x710 drivers/net/wireguard/device.c:343 rtnl_newlink_create net/core/rtnetlink.c:3485 [inline] __rtnl_newlink net/core/rtnetlink.c:3705 [inline] rtnl_newlink+0x1579/0x2070 net/core/rtnetlink.c:3718 rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x7dc/0x970 net/netlink/af_netlink.c:1368 netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2558 ___sys_sendmsg net/socket.c:2612 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xad/0xc0 mm/kasan/generic.c:492 kvfree_call_rcu+0xf8/0x790 kernel/rcu/tree.c:3372 ipv6_mc_destroy_dev+0x3b2/0x570 net/ipv6/mcast.c:2808 addrconf_ifdown+0x16d7/0x1b90 net/ipv6/addrconf.c:3935 addrconf_notify+0x1b1/0x1010 notifier_call_chain+0x18c/0x3a0 kernel/notifier.c:93 call_netdevice_notifiers_info net/core/dev.c:1970 [inline] call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] unregister_netdevice_many_notify+0xe1f/0x1900 net/core/dev.c:10938 rtnl_newlink_create net/core/rtnetlink.c:3516 [inline] __rtnl_newlink net/core/rtnetlink.c:3705 [inline] rtnl_newlink+0x1d4f/0x2070 net/core/rtnetlink.c:3718 rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x7dc/0x970 net/netlink/af_netlink.c:1368 netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2558 ___sys_sendmsg net/socket.c:2612 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xad/0xc0 mm/kasan/generic.c:492 insert_work+0x3e/0x320 kernel/workqueue.c:1647 __queue_work+0xd00/0x1010 kernel/workqueue.c:1803 call_timer_fn+0x17a/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1746 [inline] __run_timers+0x67a/0x860 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 __do_softirq+0x2ab/0x908 kernel/softirq.c:553 The buggy address belongs to the object at ffff88801c056000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff88801c056000, ffff88801c056200) The buggy address belongs to the physical page: page:ffffea0000701500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c054 head:ffffea0000701500 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012841c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5074, tgid 5074 (syz-executor.3), ts 240108442026, free_ts 240076174291 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426 alloc_slab_page+0x6a/0x160 mm/slub.c:1870 allocate_slab mm/slub.c:2017 [inline] new_slab+0x84/0x2f0 mm/slub.c:2070 ___slab_alloc+0xc85/0x1310 mm/slub.c:3223 __slab_alloc mm/slub.c:3322 [inline] __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x1af/0x270 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc+0xa8/0x230 mm/slab_common.c:1036 kmalloc include/linux/slab.h:603 [inline] kzalloc include/linux/slab.h:720 [inline] fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x445/0x1220 net/ipv6/route.c:3749 ip6_route_add+0x26/0x120 net/ipv6/route.c:3843 addrconf_prefix_route+0x329/0x500 net/ipv6/addrconf.c:2434 inet6_addr_add+0x620/0xaf0 net/ipv6/addrconf.c:3000 inet6_rtm_newaddr+0x89e/0xc80 net/ipv6/addrconf.c:4972 rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2405 discard_slab mm/slub.c:2116 [inline] __unfreeze_partials+0x1dc/0x220 mm/slub.c:2655 put_cpu_partial+0x17b/0x250 mm/slub.c:2731 __slab_free+0x2b6/0x390 mm/slub.c:3679 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x67/0x3d0 mm/slab.h:762 slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x123/0x300 mm/slub.c:3502 getname_flags+0xbc/0x4e0 fs/namei.c:140 vfs_fstatat+0x11c/0x190 fs/stat.c:294 __do_sys_newfstatat fs/stat.c:459 [inline] __se_sys_newfstatat fs/stat.c:453 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:453 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88801c056080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801c056100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801c056180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801c056200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801c056280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================