================================================================== BUG: KASAN: use-after-free in io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 Read of size 4 at addr ffff888041867804 by task iou-wrk-28809/29299 CPU: 1 PID: 29299 Comm: iou-wrk-28809 Not tainted 6.2.0-rc2-syzkaller-00313-g9b43a525db12 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 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/0x461 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 wait_woken+0x197/0x200 kernel/sched/wait.c:463 sk_stream_wait_memory+0x964/0xf30 net/core/stream.c:145 kcm_sendmsg+0x15f7/0x2360 net/kcm/kcmsock.c:934 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 sock_write_iter+0x295/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2189 [inline] io_write+0x38b/0x1560 io_uring/rw.c:918 io_issue_sqe+0x156/0x1220 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 28809: 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+0xa3/0xb0 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 29299: kasan_save_stack+0x22/0x40 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:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] __cache_free mm/slab.c:3394 [inline] __do_kmem_cache_free mm/slab.c:3580 [inline] __kmem_cache_free+0xcd/0x3b0 mm/slab.c:3587 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 wait_woken+0x197/0x200 kernel/sched/wait.c:463 sk_stream_wait_memory+0x964/0xf30 net/core/stream.c:145 kcm_sendmsg+0x15f7/0x2360 net/kcm/kcmsock.c:934 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 sock_write_iter+0x295/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2189 [inline] io_write+0x38b/0x1560 io_uring/rw.c:918 io_issue_sqe+0x156/0x1220 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+0x7b/0x90 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 wait_woken+0x197/0x200 kernel/sched/wait.c:463 sk_stream_wait_memory+0x964/0xf30 net/core/stream.c:145 kcm_sendmsg+0x15f7/0x2360 net/kcm/kcmsock.c:934 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 sock_write_iter+0x295/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2189 [inline] io_write+0x38b/0x1560 io_uring/rw.c:918 io_issue_sqe+0x156/0x1220 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 ffff888041867800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 4 bytes inside of 512-byte region [ffff888041867800, ffff888041867a00) The buggy address belongs to the physical page: page:ffffea00010619c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888041867c00 pfn:0x41867 flags: 0x4fff00000000200(slab|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000200 ffff888012440600 ffff888040000740 ffff888040000740 raw: ffff888041867c00 ffff888041867000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x140cc0(GFP_USER|__GFP_COMP), pid 28809, tgid 28798 (syz-executor.0), ts 1041423954195, free_ts 1040903763659 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_node include/linux/gfp.h:237 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x94/0x390 mm/slab.c:2574 fallback_alloc+0x1e2/0x2d0 mm/slab.c:3117 __do_cache_alloc mm/slab.c:3221 [inline] slab_alloc_node mm/slab.c:3254 [inline] __kmem_cache_alloc_node+0x174/0x510 mm/slab.c:3544 kmalloc_node_trace+0x21/0x60 mm/slab_common.c:1075 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 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 slab_destroy mm/slab.c:1619 [inline] slabs_destroy+0x85/0xc0 mm/slab.c:1639 __cache_free_alien mm/slab.c:774 [inline] cache_free_alien mm/slab.c:790 [inline] ___cache_free+0x204/0x3d0 mm/slab.c:3421 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1a0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:761 [inline] slab_alloc_node mm/slab.c:3261 [inline] __kmem_cache_alloc_node+0x26b/0x510 mm/slab.c:3544 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] ops_init+0x241/0x680 net/core/net_namespace.c:125 setup_net+0x793/0xe60 net/core/net_namespace.c:333 copy_net_ns+0x31b/0x6b0 net/core/net_namespace.c:483 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc5/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x449/0x920 kernel/fork.c:3202 __do_sys_unshare kernel/fork.c:3273 [inline] __se_sys_unshare kernel/fork.c:3271 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3271 Memory state around the buggy address: ffff888041867700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888041867780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888041867800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888041867880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888041867900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================