================================================================== BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] BUG: KASAN: use-after-free in refcount_add include/linux/refcount.h:201 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:241 [inline] BUG: KASAN: use-after-free in sock_hold include/net/sock.h:692 [inline] BUG: KASAN: use-after-free in nr_release+0x5c/0x430 net/netrom/af_netrom.c:520 Write of size 4 at addr ffff888086b2d080 by task syz-executor.0/12299 CPU: 0 PID: 12299 Comm: syz-executor.0 Not tainted 5.8.0-syzkaller #0 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+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x620 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] refcount_add include/linux/refcount.h:201 [inline] refcount_inc include/linux/refcount.h:241 [inline] sock_hold include/net/sock.h:692 [inline] nr_release+0x5c/0x430 net/netrom/af_netrom.c:520 __sock_release net/socket.c:596 [inline] sock_close+0xd8/0x260 net/socket.c:1277 __fput+0x34f/0x7b0 fs/file_table.c:281 task_work_run+0x137/0x1c0 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0xfa/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x5e/0x1a0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x416981 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:00007fffd9c8a030 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416981 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fffd9c8a120 R11: 0000000000000293 R12: 000000000118c920 R13: 000000000118c920 R14: ffffffffffffffff R15: 000000000118c10c Allocated by task 12300: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x218/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] sk_prot_alloc+0xa7/0x2b0 net/core/sock.c:1685 sk_alloc+0x35/0x300 net/core/sock.c:1739 nr_create+0x9f/0x4e0 net/netrom/af_netrom.c:433 __sock_create+0x5b3/0x8c0 net/socket.c:1427 sock_create net/socket.c:1478 [inline] __sys_socket+0xde/0x2d0 net/socket.c:1520 __do_sys_socket net/socket.c:1529 [inline] __se_sys_socket net/socket.c:1527 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1527 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 12299: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xdd/0x110 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x10a/0x220 mm/slab.c:3756 sk_prot_free net/core/sock.c:1722 [inline] __sk_destruct+0x612/0x770 net/core/sock.c:1807 sock_put include/net/sock.h:1781 [inline] nr_release+0x224/0x430 net/netrom/af_netrom.c:554 __sock_release net/socket.c:596 [inline] sock_close+0xd8/0x260 net/socket.c:1277 __fput+0x34f/0x7b0 fs/file_table.c:281 task_work_run+0x137/0x1c0 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0xfa/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x5e/0x1a0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888086b2d000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff888086b2d000, ffff888086b2d800) The buggy address belongs to the page: page:000000004aedf0be refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x86b2d flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000269ac08 ffffea0002278108 ffff8880aa440800 raw: 0000000000000000 ffff888086b2d000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888086b2cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888086b2d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888086b2d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888086b2d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888086b2d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================