RBP: 00007ffde48c7e70 R08: 0000000020000040 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 9pnet: Found fid 0 not clunked ================================================================== BUG: KASAN: use-after-free in p9_client_clunk+0x131/0x150 net/9p/client.c:1505 Read of size 8 at addr ffff8880a84ec380 by task syz-executor355/7808 CPU: 1 PID: 7808 Comm: syz-executor355 Not tainted 4.14.113 #3 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+0xaf/0x2b5 mm/kasan/report.c:393 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 p9_client_clunk+0x131/0x150 net/9p/client.c:1505 v9fs_mount+0x6b9/0x870 fs/9p/vfs_super.c:200 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/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x441249 RSP: 002b:00007ffde48c7e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441249 RDX: 00000000200005c0 RSI: 0000000020000580 RDI: 0000000000000000 RBP: 00007ffde48c7e70 R08: 0000000020000040 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7808: 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 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] p9_fid_create+0x4e/0x3b0 net/9p/client.c:918 p9_client_attach+0x7f/0x6a0 net/9p/client.c:1158 v9fs_session_init+0xc5c/0x1630 fs/9p/v9fs.c:471 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/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 7808: 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_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 p9_fid_destroy+0x1cd/0x280 net/9p/client.c:957 p9_client_destroy.cold+0x61/0xac net/9p/client.c:1121 v9fs_session_close+0x4a/0x2c0 fs/9p/v9fs.c:511 v9fs_kill_super+0x4e/0xa0 fs/9p/vfs_super.c:233 deactivate_locked_super+0x79/0xe0 fs/super.c:319 sget_userns+0x9df/0xc30 fs/super.c:537 sget+0xd6/0x120 fs/super.c:572 v9fs_mount+0xa8/0x870 fs/9p/vfs_super.c:141 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/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff8880a84ec380 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff8880a84ec380, ffff8880a84ec3e0) The buggy address belongs to the page: page:ffffea0002a13b00 count:1 mapcount:0 mapping:ffff8880a84ec000 index:0x0 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffff8880a84ec000 0000000000000000 0000000100000020 raw: ffffea00025f64a0 ffffea00027e2460 ffff8880aa8004c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a84ec280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a84ec300: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc >ffff8880a84ec380: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880a84ec400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a84ec480: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================