================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff88817a3a4dc0 by task pool_workqueue_/3 CPU: 0 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc4-syzkaller-00298-g37faf07bf90a #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+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 kthread_worker_fn+0x2ff/0xac0 kernel/kthread.c:823 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 32549: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] alloc_workqueue+0x16f/0x1490 kernel/workqueue.c:4684 wg_newlink+0x353/0x8f0 drivers/net/wireguard/device.c:343 rtnl_newlink_create net/core/rtnetlink.c:3485 [inline] __rtnl_newlink+0x1177/0x1940 net/core/rtnetlink.c:3705 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3718 rtnetlink_rcv_msg+0x3c4/0xdf0 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2558 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2612 __sys_sendmsg+0x117/0x1e0 net/socket.c:2641 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 32549: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 alloc_workqueue+0xe76/0x1490 kernel/workqueue.c:4746 wg_newlink+0x353/0x8f0 drivers/net/wireguard/device.c:343 rtnl_newlink_create net/core/rtnetlink.c:3485 [inline] __rtnl_newlink+0x1177/0x1940 net/core/rtnetlink.c:3705 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3718 rtnetlink_rcv_msg+0x3c4/0xdf0 net/core/rtnetlink.c:6444 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2558 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2612 __sys_sendmsg+0x117/0x1e0 net/socket.c:2641 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88817a3a4c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff88817a3a4c00, ffff88817a3a4e00) The buggy address belongs to the physical page: page:ffffea0005e8e900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x17a3a4 head:ffffea0005e8e900 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x57ff00000000840(slab|head|node=1|zone=2|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 057ff00000000840 ffff888012c41c80 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 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 32545, tgid 32544 (syz-executor.0), ts 1648748606180, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2297 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] mca_alloc net/ipv6/mcast.c:880 [inline] __ipv6_dev_mc_inc+0x2b7/0xc40 net/ipv6/mcast.c:936 ipv6_add_dev+0xa85/0x13d0 net/ipv6/addrconf.c:466 addrconf_notify+0x55c/0x1920 net/ipv6/addrconf.c:3589 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1970 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] register_netdevice+0xf84/0x1490 net/core/dev.c:10169 wg_newlink+0x4a5/0x8f0 drivers/net/wireguard/device.c:372 page_owner free stack trace missing Memory state around the buggy address: ffff88817a3a4c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88817a3a4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88817a3a4d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88817a3a4e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88817a3a4e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================