================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x81/0x200 lib/refcount.c:123 Read of size 4 at addr ffff88808bb14200 by task syz-executor.5/12837 CPU: 1 PID: 12837 Comm: syz-executor.5 Not tainted 5.1.0-rc5+ #72 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+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_read+0x11/0x20 mm/kasan/common.c:102 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_inc_not_zero_checked+0x81/0x200 lib/refcount.c:123 refcount_inc_checked+0x17/0x70 lib/refcount.c:156 sock_hold include/net/sock.h:647 [inline] nr_release+0x62/0x3c0 net/netrom/af_netrom.c:523 __sock_release+0xd3/0x2b0 net/socket.c:599 sock_close+0x1b/0x30 net/socket.c:1247 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/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:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4129e1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 1a 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:00007ffc18cd87a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00000000004129e1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 000000000073c900 R08: ffffffff8132caba R09: 00000000dd5371a4 R10: 00007ffc18cd8870 R11: 0000000000000293 R12: 0000000000000001 R13: 000000000073c900 R14: 0000000000051747 R15: 000000000073c0ec Allocated by task 12840: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511 __do_kmalloc mm/slab.c:3728 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3737 kmalloc include/linux/slab.h:552 [inline] sk_prot_alloc+0x19c/0x2e0 net/core/sock.c:1607 sk_alloc+0x39/0xf70 net/core/sock.c:1661 nr_create+0xb9/0x5e0 net/netrom/af_netrom.c:436 __sock_create+0x3e6/0x750 net/socket.c:1398 sock_create net/socket.c:1449 [inline] __sys_socket+0x103/0x220 net/socket.c:1491 __do_sys_socket net/socket.c:1500 [inline] __se_sys_socket net/socket.c:1498 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1498 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12837: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3500 [inline] kfree+0xcf/0x230 mm/slab.c:3823 sk_prot_free net/core/sock.c:1644 [inline] __sk_destruct+0x4f1/0x6d0 net/core/sock.c:1726 sk_destruct+0x7b/0x90 net/core/sock.c:1734 __sk_free+0xce/0x300 net/core/sock.c:1745 sk_free+0x42/0x50 net/core/sock.c:1756 sock_put include/net/sock.h:1714 [inline] nr_release+0x337/0x3c0 net/netrom/af_netrom.c:557 __sock_release+0xd3/0x2b0 net/socket.c:599 sock_close+0x1b/0x30 net/socket.c:1247 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/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:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808bb14180 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88808bb14180, ffff88808bb14980) The buggy address belongs to the page: page:ffffea00022ec500 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0xffff88808bb15280 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00022b2908 ffffea00025fea08 ffff88812c3f0c40 raw: ffff88808bb15280 ffff88808bb14180 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808bb14100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808bb14180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808bb14200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808bb14280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808bb14300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================