protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 netlink: 'syz-executor1': attribute type 18 has an invalid length. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x91/0x2e0 lib/refcount.c:120 Read of size 4 at addr ffff88806c74e400 by task syz-executor0/32320 CPU: 0 PID: 32320 Comm: syz-executor0 Not tainted 4.20.0+ #18 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+0x1db/0x2d0 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:100 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_inc_not_zero_checked+0x91/0x2e0 lib/refcount.c:120 refcount_inc_checked+0x17/0x70 lib/refcount.c:153 sock_hold include/net/sock.h:647 [inline] nr_release+0x62/0x3c0 net/netrom/af_netrom.c:523 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1141 __fput+0x3c5/0xb10 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 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+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411c91 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 94 19 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:00007ffcd7512f90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000411c91 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000000 R08: 00000000817dcf89 R09: 0000000000000000 R10: 00007ffcd7512ec0 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000087 R15: 0000000000000000 Allocated by task 32321: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc mm/kasan/common.c:482 [inline] kasan_kmalloc+0xcf/0xe0 mm/kasan/common.c:455 __do_kmalloc mm/slab.c:3709 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3718 kmalloc include/linux/slab.h:550 [inline] sk_prot_alloc+0x19c/0x2e0 net/core/sock.c:1477 sk_alloc+0xd7/0x1690 net/core/sock.c:1531 nr_create+0xb9/0x5e0 net/netrom/af_netrom.c:436 __sock_create+0x532/0x930 net/socket.c:1277 sock_create net/socket.c:1317 [inline] __sys_socket+0x106/0x260 net/socket.c:1347 __do_sys_socket net/socket.c:1356 [inline] __se_sys_socket net/socket.c:1354 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1354 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 32320: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kfree+0xcf/0x230 mm/slab.c:3804 sk_prot_free net/core/sock.c:1514 [inline] __sk_destruct+0x76d/0xa60 net/core/sock.c:1596 sk_destruct+0x7b/0x90 net/core/sock.c:1604 __sk_free+0xce/0x300 net/core/sock.c:1615 sk_free+0x42/0x50 net/core/sock.c:1626 sock_put include/net/sock.h:1707 [inline] nr_release+0x337/0x3c0 net/netrom/af_netrom.c:557 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1141 __fput+0x3c5/0xb10 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 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+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88806c74e380 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88806c74e380, ffff88806c74eb80) The buggy address belongs to the page: page:ffffea0001b1d380 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001adca88 ffffea000240f708 ffff88812c3f0c40 raw: 0000000000000000 ffff88806c74e380 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806c74e300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806c74e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806c74e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806c74e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806c74e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb kobject: 'loop1' (00000000d4448025): fill_kobj_path: path = '/devices/virtual/block/loop1' ==================================================================