kobject: 'loop1' (000000000c9830e9): fill_kobj_path: path = '/devices/virtual/block/loop1' RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f068b95e6d4 R13: 00000000004c2b7f R14: 00000000004d41b8 R15: 0000000000000006 ================================================================== BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604 Read of size 1 at addr ffff8801c8c77b3a by task syz-executor3/31988 CPU: 1 PID: 31988 Comm: syz-executor3 Not tainted 4.19.0-rc6-next-20181003+ #86 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+0x1d3/0x2c4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 string+0x298/0x2d0 lib/vsprintf.c:604 vsnprintf+0x48e/0x1b60 lib/vsprintf.c:2298 vscnprintf+0x2d/0x80 lib/vsprintf.c:2401 vprintk_store+0x43/0x510 kernel/printk/printk.c:1846 vprintk_emit+0x1c1/0x930 kernel/printk/printk.c:1904 vprintk_default+0x28/0x30 kernel/printk/printk.c:1962 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1995 ovl_lookup_index.cold.14+0xe8/0x1f8 fs/overlayfs/namei.c:689 ovl_lookup+0x9f2/0x29c0 fs/overlayfs/namei.c:1022 lookup_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x252a/0x5160 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f068b95dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f068b95dc90 RCX: 0000000000457579 RDX: 0000000000000001 RSI: 0000000020000200 RDI: ffffffffffffff9c RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f068b95e6d4 R13: 00000000004c2b7f R14: 00000000004d41b8 R15: 0000000000000006 Allocated by task 31988: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc_array include/linux/slab.h:669 [inline] kcalloc include/linux/slab.h:680 [inline] ovl_get_index_name_fh+0x57/0x180 fs/overlayfs/namei.c:596 ovl_get_index_name+0x5c/0x80 fs/overlayfs/namei.c:631 ovl_lookup_index+0xe4/0x700 fs/overlayfs/namei.c:678 ovl_lookup+0x9f2/0x29c0 fs/overlayfs/namei.c:1022 lookup_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x252a/0x5160 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3813 dccp_feat_entry_destructor.part.4+0x48/0x60 net/dccp/feat.c:418 dccp_feat_entry_destructor net/dccp/feat.c:416 [inline] dccp_feat_list_purge+0xd4/0x200 net/dccp/feat.c:549 dccp_destroy_sock+0x2fc/0x400 net/dccp/proto.c:239 inet_csk_destroy_sock+0x19f/0x440 net/ipv4/inet_connection_sock.c:835 dccp_close+0xaa3/0xe70 net/dccp/proto.c:1087 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428 __sock_release+0x1d9/0x250 net/socket.c:580 sock_release+0x17/0x20 net/socket.c:599 inet_ctl_sock_destroy include/net/inet_common.h:54 [inline] dccp_v4_exit_net+0x66/0x80 net/dccp/ipv4.c:1023 ops_exit_list.isra.7+0xb0/0x160 net/core/net_namespace.c:153 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551 process_one_work+0xc8b/0x1b80 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8801c8c77b00 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 58 bytes inside of 64-byte region [ffff8801c8c77b00, ffff8801c8c77b40) The buggy address belongs to the page: page:ffffea0007231dc0 count:1 mapcount:0 mapping:ffff8801da800340 index:0xffff8801c8c77a80 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0006f55288 ffffea00070a35c8 ffff8801da800340 raw: ffff8801c8c77a80 ffff8801c8c77000 0000000100000015 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c8c77a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801c8c77a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801c8c77b00: 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc fc ^ ffff8801c8c77b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801c8c77c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================