================================================================== BUG: KASAN: use-after-free in io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 Read of size 4 at addr ffff888021131804 by task iou-wrk-25234/25269 CPU: 1 PID: 25269 Comm: iou-wrk-25234 Not tainted 6.2.0-rc2-syzkaller-00256-ga689b938df39 #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 __skb_wait_for_more_packets+0x3f8/0x5e0 net/core/datagram.c:120 __skb_recv_datagram+0x175/0x220 net/core/datagram.c:303 skb_recv_datagram+0x89/0xb0 net/core/datagram.c:315 netlink_recvmsg+0xdd/0xe50 net/netlink/af_netlink.c:1954 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] ____sys_recvmsg+0x2c7/0x610 net/socket.c:2695 __sys_recvmsg_sock+0x37/0x50 net/socket.c:2750 io_recvmsg+0x9a7/0x1e00 io_uring/net.c:784 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 25234: 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 25269: 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 __skb_wait_for_more_packets+0x3f8/0x5e0 net/core/datagram.c:120 __skb_recv_datagram+0x175/0x220 net/core/datagram.c:303 skb_recv_datagram+0x89/0xb0 net/core/datagram.c:315 netlink_recvmsg+0xdd/0xe50 net/netlink/af_netlink.c:1954 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] ____sys_recvmsg+0x2c7/0x610 net/socket.c:2695 __sys_recvmsg_sock+0x37/0x50 net/socket.c:2750 io_recvmsg+0x9a7/0x1e00 io_uring/net.c:784 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 __skb_wait_for_more_packets+0x3f8/0x5e0 net/core/datagram.c:120 __skb_recv_datagram+0x175/0x220 net/core/datagram.c:303 skb_recv_datagram+0x89/0xb0 net/core/datagram.c:315 netlink_recvmsg+0xdd/0xe50 net/netlink/af_netlink.c:1954 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] ____sys_recvmsg+0x2c7/0x610 net/socket.c:2695 __sys_recvmsg_sock+0x37/0x50 net/socket.c:2750 io_recvmsg+0x9a7/0x1e00 io_uring/net.c:784 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 The buggy address belongs to the object at ffff888021131800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 4 bytes inside of 512-byte region [ffff888021131800, ffff888021131a00) The buggy address belongs to the physical page: page:ffffea0000844c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21130 head:ffffea0000844c00 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012441c80 dead000000000100 dead000000000122 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1297, tgid 1297 (kworker/u4:5), ts 8694313873, free_ts 0 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] alloc_bprm+0x51/0x900 fs/exec.c:1510 kernel_execve+0xaf/0x500 fs/exec.c:1981 call_usermodehelper_exec_async+0x2e7/0x580 kernel/umh.c:113 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 page_owner free stack trace missing Memory state around the buggy address: ffff888021131700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888021131780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021131800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021131880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021131900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================