================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:72 [inline] BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:147 [inline] BUG: KASAN: use-after-free in __refcount_add_not_zero include/linux/refcount.h:152 [inline] BUG: KASAN: use-after-free in __refcount_inc_not_zero include/linux/refcount.h:227 [inline] BUG: KASAN: use-after-free in refcount_inc_not_zero include/linux/refcount.h:245 [inline] BUG: KASAN: use-after-free in io_worker_get+0x77/0x2a0 io_uring/io-wq.c:153 Read of size 4 at addr ffff888031c87400 by task syz-executor.2/11306 CPU: 1 PID: 11306 Comm: syz-executor.2 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+0x1b1/0x290 lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:306 print_report+0x107/0x1f0 mm/kasan/report.c:417 kasan_report+0xcd/0x100 mm/kasan/report.c:517 kasan_check_range+0x2a7/0x2e0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:72 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] refcount_read include/linux/refcount.h:147 [inline] __refcount_add_not_zero include/linux/refcount.h:152 [inline] __refcount_inc_not_zero include/linux/refcount.h:227 [inline] refcount_inc_not_zero include/linux/refcount.h:245 [inline] io_worker_get+0x77/0x2a0 io_uring/io-wq.c:153 io_wq_for_each_worker io_uring/io-wq.c:846 [inline] io_wq_exit_workers io_uring/io-wq.c:1250 [inline] io_wq_put_and_exit+0x2f8/0xcb0 io_uring/io-wq.c:1289 io_uring_clean_tctx+0x164/0x1d0 io_uring/tctx.c:193 io_uring_cancel_generic+0x5f1/0x670 io_uring/io_uring.c:3145 io_uring_files_cancel include/linux/io_uring.h:55 [inline] do_exit+0x2ad/0x2150 kernel/exit.c:822 do_group_exit+0x1fd/0x2b0 kernel/exit.c:1012 get_signal+0x1701/0x17c0 kernel/signal.c:2859 arch_do_signal_or_restart+0x7b/0x5e0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f1bc608c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1bc6d0f168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000002000 RBX: 00007f1bc61abf80 RCX: 00007f1bc608c0c9 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000000000009 RBP: 00007f1bc60e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcb785d77f R14: 00007f1bc6d0f300 R15: 0000000000022000 Allocated by task 11306: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x3d/0x60 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380 kmalloc_node include/linux/slab.h:606 [inline] kzalloc_node include/linux/slab.h:731 [inline] create_io_worker+0xef/0x630 io_uring/io-wq.c:801 io_wqe_create_worker io_uring/io-wq.c:310 [inline] io_wqe_enqueue+0x9eb/0xd50 io_uring/io-wq.c:936 io_queue_iowq+0x2ac/0x3a0 io_uring/io_uring.c:475 io_queue_async+0x42b/0x600 io_uring/io_uring.c:2013 io_queue_sqe io_uring/io_uring.c:2037 [inline] io_submit_sqe io_uring/io_uring.c:2286 [inline] io_submit_sqes+0xe69/0x1ba0 io_uring/io_uring.c:2397 __do_sys_io_uring_enter io_uring/io_uring.c:3345 [inline] __se_sys_io_uring_enter+0x335/0x2510 io_uring/io_uring.c:3277 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 11306: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x3d/0x60 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:518 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x71/0x110 mm/slub.c:3800 io_wq_cancel_tw_create io_uring/io-wq.c:1233 [inline] io_wq_exit_workers io_uring/io-wq.c:1244 [inline] io_wq_put_and_exit+0x137/0xcb0 io_uring/io-wq.c:1289 io_uring_clean_tctx+0x164/0x1d0 io_uring/tctx.c:193 io_uring_cancel_generic+0x5f1/0x670 io_uring/io_uring.c:3145 io_uring_files_cancel include/linux/io_uring.h:55 [inline] do_exit+0x2ad/0x2150 kernel/exit.c:822 do_group_exit+0x1fd/0x2b0 kernel/exit.c:1012 get_signal+0x1701/0x17c0 kernel/signal.c:2859 arch_do_signal_or_restart+0x7b/0x5e0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x2b/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:488 task_work_add+0x87/0x340 kernel/task_work.c:48 io_queue_worker_create+0x1e2/0x430 io_uring/io-wq.c:373 sched_submit_work kernel/sched/core.c:6597 [inline] schedule+0x63/0x190 kernel/sched/core.c:6628 schedule_timeout+0x1aa/0x2f0 kernel/time/timer.c:2167 io_schedule_timeout+0x96/0x120 kernel/sched/core.c:8799 do_wait_for_common+0x3ea/0x560 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common_io kernel/sched/completion.c:123 [inline] wait_for_completion_io_timeout+0x44/0x60 kernel/sched/completion.c:191 submit_bio_wait+0x15b/0x240 block/bio.c:1384 blkdev_issue_flush+0xa1/0xf0 block/blk-flush.c:467 ext4_sync_file+0x600/0x850 fs/ext4/fsync.c:177 io_fsync+0xd1/0x160 io_uring/sync.c:78 io_issue_sqe+0x44e/0xcd0 io_uring/io_uring.c:1856 io_wq_submit_work+0x44a/0x9c0 io_uring/io_uring.c:1932 io_worker_handle_work+0x8bb/0xe30 io_uring/io-wq.c:587 io_wqe_worker+0x34c/0xdd0 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+0x2b/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:488 task_work_add+0x87/0x340 kernel/task_work.c:48 io_queue_worker_create+0x1e2/0x430 io_uring/io-wq.c:373 sched_submit_work kernel/sched/core.c:6597 [inline] schedule+0x63/0x190 kernel/sched/core.c:6628 jbd2_log_wait_commit+0x295/0x4a0 fs/jbd2/journal.c:709 ext4_fc_commit+0x859/0x1c20 ext4_fsync_journal fs/ext4/fsync.c:115 [inline] ext4_sync_file+0x4ce/0x850 fs/ext4/fsync.c:174 io_fsync+0xd1/0x160 io_uring/sync.c:78 io_issue_sqe+0x44e/0xcd0 io_uring/io_uring.c:1856 io_wq_submit_work+0x44a/0x9c0 io_uring/io_uring.c:1932 io_worker_handle_work+0x8bb/0xe30 io_uring/io-wq.c:587 io_wqe_worker+0x34c/0xdd0 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 ffff888031c87400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff888031c87400, ffff888031c87600) The buggy address belongs to the physical page: page:ffffea0000c72100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31c84 head:ffffea0000c72100 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 anon flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012841c80 0000000000000000 dead000000000001 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 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5111, tgid 5111 (syz-executor.0), ts 270638443693, free_ts 0 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283 __alloc_pages+0x259/0x560 mm/page_alloc.c:5549 alloc_slab_page+0xbd/0x190 mm/slub.c:1851 allocate_slab+0x5e/0x3c0 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0x782/0xe20 mm/slub.c:3193 __slab_alloc mm/slub.c:3292 [inline] __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x25b/0x340 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x9e/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] fib6_info_alloc+0x2c/0xd0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x43d/0x12e0 net/ipv6/route.c:3749 addrconf_f6i_alloc+0x45e/0x800 net/ipv6/route.c:4571 fixup_permanent_addr net/ipv6/addrconf.c:3461 [inline] addrconf_permanent_addr+0x1bc/0x700 net/ipv6/addrconf.c:3500 addrconf_notify+0x8a8/0x1010 net/ipv6/addrconf.c:3572 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:455 __dev_notify_flags+0x308/0x5e0 dev_change_flags+0xe8/0x190 net/core/dev.c:8607 do_setlink+0xef5/0x3d40 net/core/rtnetlink.c:2827 page_owner free stack trace missing Memory state around the buggy address: ffff888031c87300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888031c87380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888031c87400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888031c87480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888031c87500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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