RDX: 0000000000003326 RSI: 0000000020000200 RDI: ffffffffffffff9c RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad3a5fa6d4 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 ffff8801b96e653a by task syz-executor1/10108 CPU: 1 PID: 10108 Comm: syz-executor1 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:00007fad3a5f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fad3a5f9c90 RCX: 0000000000457579 RDX: 0000000000003326 RSI: 0000000020000200 RDI: ffffffffffffff9c RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad3a5fa6d4 R13: 00000000004c2b7f R14: 00000000004d41b8 R15: 0000000000000006 Allocated by task 10108: 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 8980: 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 put_mountpoint+0x2c2/0x3d0 fs/namespace.c:764 attach_recursive_mnt+0x489/0xb60 fs/namespace.c:1992 graft_tree+0x1aa/0x240 fs/namespace.c:2065 do_add_mount+0x1fe/0x370 fs/namespace.c:2567 do_new_mount_fc fs/namespace.c:2600 [inline] do_new_mount fs/namespace.c:2652 [inline] do_mount+0x888/0x1d90 fs/namespace.c:2974 ksys_mount+0x12d/0x140 fs/namespace.c:3190 __do_sys_mount fs/namespace.c:3204 [inline] __se_sys_mount fs/namespace.c:3201 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3201 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801b96e6500 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 58 bytes inside of 64-byte region [ffff8801b96e6500, ffff8801b96e6540) The buggy address belongs to the page: page:ffffea0006e5b980 count:1 mapcount:0 mapping:ffff8801da800340 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea00071a6dc8 ffffea00071cd808 ffff8801da800340 raw: 0000000000000000 ffff8801b96e6000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b96e6400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801b96e6480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801b96e6500: 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc fc ^ ffff8801b96e6580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801b96e6600: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ==================================================================