netlink: 20 bytes leftover after parsing attributes in process `syz-executor.1'. ================================================================== 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 26283 at addr ffff88807569356d by task syz-executor.2/3628 CPU: 0 PID: 3628 Comm: syz-executor.2 Not tainted 4.14.142 #0 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+0x138/0x197 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+0xa9/0x2af 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+0x379/0x1780 net/9p/protocol.c:540 p9_client_version net/9p/client.c:990 [inline] p9_client_create+0xa1f/0x1120 net/9p/client.c:1088 v9fs_session_init+0x1dc/0x1620 fs/9p/v9fs.c:422 v9fs_mount+0x7d/0x870 fs/9p/vfs_super.c:135 mount_fs+0x97/0x2a1 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+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4598e9 RSP: 002b:00007fa762c36c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004598e9 RDX: 00000000200000c0 RSI: 0000000020000480 RDI: 0000000000000000 RBP: 000000000075bf20 R08: 00000000200001c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa762c376d4 R13: 00000000004c5e68 R14: 00000000004da9b0 R15: 00000000ffffffff Allocated by task 3628: 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+0x73a/0xa90 net/9p/client.c:728 p9_client_prepare_req net/9p/client.c:718 [inline] p9_client_rpc+0x170/0x1180 net/9p/client.c:763 p9_client_version net/9p/client.c:980 [inline] p9_client_create+0x997/0x1120 net/9p/client.c:1088 v9fs_session_init+0x1dc/0x1620 fs/9p/v9fs.c:422 v9fs_mount+0x7d/0x870 fs/9p/vfs_super.c:135 mount_fs+0x97/0x2a1 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+0x1e8/0x640 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 ffff888075693540 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 45 bytes inside of 16384-byte region [ffff888075693540, ffff888075697540) The buggy address belongs to the page: page:ffffea0001d5a400 count:1 mapcount:0 mapping:ffff888075693540 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffff888075693540 0000000000000000 0000000100000001 raw: ffffea0002500c20 ffff8880aa801c48 ffff8880aa802200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888075695400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888075695480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888075695500: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ^ ffff888075695580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888075695600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================