================================================================== BUG: KASAN: use-after-free in io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 Read of size 4 at addr ffff888040898804 by task iou-wrk-29101/29137 CPU: 1 PID: 29137 Comm: iou-wrk-29101 Not tainted 6.2.0-rc3-syzkaller-00030-ge8f60cd7db24 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 schedule_timeout+0x1e1/0x2a0 kernel/time/timer.c:2143 unix_wait_for_peer+0x244/0x280 net/unix/af_unix.c:1449 unix_dgram_sendmsg+0x19a1/0x1bc0 net/unix/af_unix.c:2047 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 __sys_sendmsg_sock+0x2a/0x40 net/socket.c:2542 io_sendmsg+0x24c/0x810 io_uring/net.c:315 io_issue_sqe+0x695/0x1220 io_uring/io_uring.c:1856 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1932 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/0xe40 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 29101: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc_node include/linux/slab.h:606 [inline] kzalloc_node include/linux/slab.h:731 [inline] create_io_worker+0x10c/0x630 io_uring/io-wq.c:801 create_worker_cb+0x1fb/0x270 io_uring/io-wq.c:339 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x2450 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 29137: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800 io_wq_cancel_tw_create io_uring/io-wq.c:1233 [inline] io_queue_worker_create+0x567/0x660 io_uring/io-wq.c:381 io_wqe_dec_running+0x1e4/0x240 io_uring/io-wq.c:410 io_wq_worker_sleeping+0xa6/0xc0 io_uring/io-wq.c:698 sched_submit_work kernel/sched/core.c:6597 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6628 schedule_timeout+0x1e1/0x2a0 kernel/time/timer.c:2143 unix_wait_for_peer+0x244/0x280 net/unix/af_unix.c:1449 unix_dgram_sendmsg+0x19a1/0x1bc0 net/unix/af_unix.c:2047 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 __sys_sendmsg_sock+0x2a/0x40 net/socket.c:2542 io_sendmsg+0x24c/0x810 io_uring/net.c:315 io_issue_sqe+0x695/0x1220 io_uring/io_uring.c:1856 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1932 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/0xe40 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 task_work_add+0x7f/0x2c0 kernel/task_work.c:48 io_queue_worker_create+0x41d/0x660 io_uring/io-wq.c:373 io_wqe_dec_running+0x1e4/0x240 io_uring/io-wq.c:410 io_wq_worker_sleeping+0xa6/0xc0 io_uring/io-wq.c:698 sched_submit_work kernel/sched/core.c:6597 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6628 schedule_timeout+0x1e1/0x2a0 kernel/time/timer.c:2143 unix_wait_for_peer+0x244/0x280 net/unix/af_unix.c:1449 unix_dgram_sendmsg+0x19a1/0x1bc0 net/unix/af_unix.c:2047 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 __sys_sendmsg_sock+0x2a/0x40 net/socket.c:2542 io_sendmsg+0x24c/0x810 io_uring/net.c:315 io_issue_sqe+0x695/0x1220 io_uring/io_uring.c:1856 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1932 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/0xe40 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 kvfree_call_rcu+0x78/0x8f0 kernel/rcu/tree.c:3376 ma_put net/ipv6/mcast.c:869 [inline] ma_put+0x11c/0x180 net/ipv6/mcast.c:865 __ipv6_dev_mc_dec+0x27c/0x340 net/ipv6/mcast.c:982 ipv6_mc_destroy_dev+0x2ca/0x630 net/ipv6/mcast.c:2800 addrconf_ifdown.isra.0+0x12c2/0x1920 net/ipv6/addrconf.c:3893 addrconf_notify+0x109/0x1c80 net/ipv6/addrconf.c:3673 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] unregister_netdevice_many_notify+0xa2b/0x19e0 net/core/dev.c:10839 unregister_netdevice_many net/core/dev.c:10895 [inline] default_device_exit_batch+0x451/0x590 net/core/dev.c:11348 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174 setup_net+0x9bd/0xe60 net/core/net_namespace.c:356 copy_net_ns+0x31b/0x6b0 net/core/net_namespace.c:483 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x3b3/0x4a0 kernel/nsproxy.c:179 copy_process+0x30d3/0x7520 kernel/fork.c:2269 kernel_clone+0xeb/0x990 kernel/fork.c:2681 __do_sys_clone+0xba/0x100 kernel/fork.c:2822 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888040898800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 4 bytes inside of 512-byte region [ffff888040898800, ffff888040898a00) The buggy address belongs to the physical page: page:ffffea0001022600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40898 head:ffffea0001022600 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012441c80 ffffea0001f4dd00 dead000000000002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5115, tgid 5115 (syz-executor.4), ts 169879341531, free_ts 169877691422 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491 kmalloc_trace+0x26/0x60 mm/slab_common.c:1062 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] inetdev_init+0x66/0x580 net/ipv4/devinet.c:269 inetdev_event+0xe20/0x16c0 net/ipv4/devinet.c:1535 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] register_netdevice+0xfb4/0x1640 net/core/dev.c:10078 rtnl_newlink_create net/core/rtnetlink.c:3409 [inline] __rtnl_newlink+0x15a1/0x1840 net/core/rtnetlink.c:3624 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 __stack_depot_save+0x16d/0x560 lib/stackdepot.c:506 kasan_save_stack+0x35/0x40 mm/kasan/common.c:46 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] ref_tracker_alloc+0x158/0x560 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4020 [inline] netdev_hold include/linux/netdevice.h:4049 [inline] netdev_hold include/linux/netdevice.h:4044 [inline] inetdev_init+0x23d/0x580 net/ipv4/devinet.c:282 inetdev_event+0xe20/0x16c0 net/ipv4/devinet.c:1535 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] register_netdevice+0xfb4/0x1640 net/core/dev.c:10078 vxcan_newlink+0x371/0x610 drivers/net/can/vxcan.c:249 rtnl_newlink_create net/core/rtnetlink.c:3407 [inline] __rtnl_newlink+0x10c2/0x1840 net/core/rtnetlink.c:3624 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141 Memory state around the buggy address: ffff888040898700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888040898780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888040898800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888040898880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888040898900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================