================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline] BUG: KASAN: use-after-free in atomic_long_read include/asm-generic/atomic-long.h:29 [inline] BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0x8e/0x610 kernel/locking/mutex.c:1227 Read of size 8 at addr ffff888028b2a008 by task iou-sqp-31985/31988 CPU: 1 PID: 31988 Comm: iou-sqp-31985 Not tainted 5.12.0-rc1-next-20210305-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline] atomic_long_read include/asm-generic/atomic-long.h:29 [inline] __mutex_unlock_slowpath+0x8e/0x610 kernel/locking/mutex.c:1227 io_sq_thread+0x1241/0x19e0 fs/io_uring.c:6736 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 31985: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc mm/kasan/common.c:506 [inline] ____kasan_kmalloc mm/kasan/common.c:465 [inline] __kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:686 [inline] io_get_sq_data fs/io_uring.c:7139 [inline] io_sq_offload_create fs/io_uring.c:7826 [inline] io_uring_create fs/io_uring.c:9355 [inline] io_uring_setup+0x1621/0x2910 fs/io_uring.c:9438 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 28: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kfree+0xe5/0x7f0 mm/slub.c:4215 io_put_sq_data fs/io_uring.c:7078 [inline] io_sq_thread_finish+0x50b/0x650 fs/io_uring.c:7101 io_ring_ctx_free fs/io_uring.c:8359 [inline] io_ring_exit_work+0x82/0x9a0 fs/io_uring.c:8490 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 kvfree_call_rcu+0x74/0x8c0 kernel/rcu/tree.c:3597 neigh_destroy+0x3ff/0x5f0 net/core/neighbour.c:858 neigh_release include/net/neighbour.h:425 [inline] neigh_cleanup_and_release+0x1fd/0x340 net/core/neighbour.c:103 neigh_del net/core/neighbour.c:193 [inline] neigh_remove_one+0x3cf/0x450 net/core/neighbour.c:214 neigh_forced_gc net/core/neighbour.c:243 [inline] neigh_alloc net/core/neighbour.c:390 [inline] ___neigh_create+0x1698/0x25c0 net/core/neighbour.c:578 ip6_finish_output2+0xf1f/0x1700 net/ipv6/ip6_output.c:114 __ip6_finish_output net/ipv6/ip6_output.c:182 [inline] __ip6_finish_output+0x4c1/0xe10 net/ipv6/ip6_output.c:161 ip6_finish_output+0x35/0x200 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:215 dst_output include/net/dst.h:448 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ndisc_send_skb+0xa99/0x1750 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3877 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745 __run_timers kernel/time/timer.c:1726 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 The buggy address belongs to the object at ffff888028b2a000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 8 bytes inside of 1024-byte region [ffff888028b2a000, ffff888028b2a400) The buggy address belongs to the page: page:00000000b3dc570e refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888028b2d800 pfn:0x28b28 head:00000000b3dc570e order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 ffff888010840888 ffffea000049fe08 ffff888010841dc0 raw: ffff888028b2d800 000000000010000e 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888028b29f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888028b29f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888028b2a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888028b2a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888028b2a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================