================================================================== BUG: KASAN: use-after-free in sk_psock_unlink+0x3dd/0x4b0 net/core/sock_map.c:988 Read of size 4 at addr ffff8880981a7a58 by task syz-executor.0/24873 CPU: 0 PID: 24873 Comm: syz-executor.0 Not tainted 5.2.0-rc5-next-20190617 #16 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 sk_psock_unlink+0x3dd/0x4b0 net/core/sock_map.c:988 tcp_bpf_remove+0x21/0x50 net/ipv4/tcp_bpf.c:535 tcp_bpf_close+0x130/0x390 net/ipv4/tcp_bpf.c:575 inet_release+0xe0/0x1f0 net/ipv4/af_inet.c:427 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:470 __sock_release+0xce/0x2a0 net/socket.c:601 sock_close+0x1b/0x30 net/socket.c:1273 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffe7b8c41f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000082ada23f R09: 0000000082ada243 R10: 00007ffe7b8c42d0 R11: 0000000000000293 R12: 0000000000761148 R13: 0000000000184496 R14: 00000000001844c3 R15: 000000000075bf2c Allocated by task 24874: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 kmem_cache_alloc_trace+0x151/0x750 mm/slab.c:3540 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:743 [inline] sock_hash_alloc net/core/sock_map.c:797 [inline] sock_hash_alloc+0x1e3/0x5b0 net/core/sock_map.c:781 find_and_alloc_map kernel/bpf/syscall.c:121 [inline] map_create kernel/bpf/syscall.c:569 [inline] __do_sys_bpf+0x44f/0x42c0 kernel/bpf/syscall.c:2812 __se_sys_bpf kernel/bpf/syscall.c:2789 [inline] __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:2789 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 18824: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3417 [inline] kfree+0x10a/0x2c0 mm/slab.c:3746 sock_hash_free+0x327/0x4a0 net/core/sock_map.c:860 bpf_map_free_deferred+0xb3/0x100 kernel/bpf/syscall.c:307 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8880981a7a40 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of 512-byte region [ffff8880981a7a40, ffff8880981a7c40) The buggy address belongs to the page: page:ffffea00026069c0 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00024d8748 ffffea0002238648 ffff8880aa400a80 raw: 0000000000000000 ffff8880981a7040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880981a7900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880981a7980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880981a7a00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880981a7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880981a7b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================