================================================================== BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_fetch_add include/asm-generic/atomic-instrumented.h:112 [inline] BUG: KASAN: use-after-free in refcount_add include/linux/refcount.h:188 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:228 [inline] BUG: KASAN: use-after-free in sock_hold include/net/sock.h:690 [inline] BUG: KASAN: use-after-free in nr_release+0x62/0x490 net/netrom/af_netrom.c:498 Write of size 4 at addr ffff88807f5c8080 by task syz-executor.4/10763 CPU: 0 PID: 10763 Comm: syz-executor.4 Not tainted 5.6.0-rc3-next-20200228-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:618 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x128/0x190 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_fetch_add include/asm-generic/atomic-instrumented.h:112 [inline] refcount_add include/linux/refcount.h:188 [inline] refcount_inc include/linux/refcount.h:228 [inline] sock_hold include/net/sock.h:690 [inline] nr_release+0x62/0x490 net/netrom/af_netrom.c:498 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1283 __fput+0x2da/0x850 fs/file_table.c:280 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4163e1 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:00007ffcee380120 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00000000004163e1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: 00ffffffffffffff R09: 00ffffffffffffff R10: 00007ffcee380200 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 00000000000d7f25 R15: 000000000076c0ec Allocated by task 10767: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:492 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:465 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] sk_prot_alloc+0x223/0x2f0 net/core/sock.c:1604 sk_alloc+0x36/0xfa0 net/core/sock.c:1658 nr_create+0xb2/0x5e0 net/netrom/af_netrom.c:411 __sock_create+0x3cb/0x730 net/socket.c:1433 sock_create net/socket.c:1484 [inline] __sys_socket+0xef/0x200 net/socket.c:1526 __do_sys_socket net/socket.c:1535 [inline] __se_sys_socket net/socket.c:1533 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1533 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 10763: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:314 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:453 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 sk_prot_free net/core/sock.c:1641 [inline] __sk_destruct+0x5ad/0x7c0 net/core/sock.c:1725 sk_destruct+0xc6/0x100 net/core/sock.c:1740 __sk_free+0xef/0x3d0 net/core/sock.c:1751 sk_free+0x78/0xa0 net/core/sock.c:1762 sock_put include/net/sock.h:1777 [inline] nr_release+0x3c8/0x490 net/netrom/af_netrom.c:532 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1283 __fput+0x2da/0x850 fs/file_table.c:280 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88807f5c8000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88807f5c8000, ffff88807f5c8800) The buggy address belongs to the page: page:ffffea0001fd7200 refcount:1 mapcount:0 mapping:00000000f94862e6 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a16d48 ffffea000234ea48 ffff8880aa000e00 raw: 0000000000000000 ffff88807f5c8000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88807f5c7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807f5c8000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807f5c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807f5c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807f5c8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================