==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: slab-out-of-bounds in pdu_read+0x90/0xd0 net/9p/protocol.c:64
Read of size 31915 at addr ffff88805d5790ad by task syz-executor.3/1977

CPU: 0 PID: 1977 Comm: syz-executor.3 Not tainted 4.14.119 #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x11e/0x2db mm/kasan/report.c:393
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 memcpy+0x24/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 pdu_read+0x90/0xd0 net/9p/protocol.c:64
 p9pdu_vreadf net/9p/protocol.c:167 [inline]
 p9pdu_readf+0xd21/0x1810 net/9p/protocol.c:540
 p9_client_version net/9p/client.c:990 [inline]
 p9_client_create+0xa2b/0x1130 net/9p/client.c:1088
 v9fs_session_init+0x1dc/0x16b0 fs/9p/v9fs.c:422
 v9fs_mount+0x7d/0x870 fs/9p/vfs_super.c:135
 mount_fs+0x9d/0x2a7 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x417/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1eb/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x458da9
RSP: 002b:00007f9a86d99c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000458da9
RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000
RBP: 000000000073bf00 R08: 0000000020000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9a86d9a6d4
R13: 00000000004c4e93 R14: 00000000004d8df0 R15: 00000000ffffffff

Allocated by task 1977:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15d/0x7a0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 p9_fcall_alloc+0x1d/0x90 net/9p/client.c:242
 p9_tag_alloc net/9p/client.c:312 [inline]
 p9_client_prepare_req.part.0+0x73c/0xa90 net/9p/client.c:728
 p9_client_prepare_req net/9p/client.c:718 [inline]
 p9_client_rpc+0x170/0x1190 net/9p/client.c:763
 p9_client_version net/9p/client.c:980 [inline]
 p9_client_create+0x9a3/0x1130 net/9p/client.c:1088
 v9fs_session_init+0x1dc/0x16b0 fs/9p/v9fs.c:422
 v9fs_mount+0x7d/0x870 fs/9p/vfs_super.c:135
 mount_fs+0x9d/0x2a7 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x417/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1eb/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88805d579080
 which belongs to the cache kmalloc-16384 of size 16384
The buggy address is located 45 bytes inside of
 16384-byte region [ffff88805d579080, ffff88805d57d080)
The buggy address belongs to the page:
page:ffffea0001755e00 count:1 mapcount:0 mapping:ffff88805d579080 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffff88805d579080 0000000000000000 0000000100000001
raw: ffffea0001785020 ffffea000182f020 ffff8880aa802200 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805d57af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805d57b000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805d57b080: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88805d57b100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805d57b180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
overlayfs: filesystem on './file0' not supported as upperdir