Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 9pnet: Found fid 0 not clunked Call Trace: ================================================================== __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 BUG: KASAN: use-after-free in p9_client_clunk+0x1fc/0x240 net/9p/client.c:1505 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 Read of size 8 at addr ffff88809780b000 by task syz-executor.0/29887 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x2c1/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] register_shrinker+0x1ab/0x220 mm/vmscan.c:284 sget_userns+0x9aa/0xc10 fs/super.c:535 sget+0xd1/0x110 fs/super.c:572 v9fs_mount+0x9e/0x860 fs/9p/vfs_super.c:141 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e219 RSP: 002b:00007fe174050c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00007fe174050ca0 R08: 0000000020000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000027 R13: 00007ffc77158c9f R14: 00007fe1740519c0 R15: 000000000119bf8c CPU: 0 PID: 29887 Comm: syz-executor.0 Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 9pnet: Found fid 0 not clunked Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan: CONFIG_KASAN_INLINE enabled kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN p9_client_clunk+0x1fc/0x240 net/9p/client.c:1505 Modules linked in: v9fs_mount+0x69f/0x860 fs/9p/vfs_super.c:200 CPU: 1 PID: 29891 Comm: syz-executor.1 Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 mount_fs+0x92/0x2a0 fs/super.c:1237 task: ffff8880a5f424c0 task.stack: ffff88808c9c8000 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 RIP: 0010:__lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 RSP: 0018:ffff88808c9cf7a0 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000018 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: ffff8880a5f424c0 R12: 0000000000000018 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8beb5d40 FS: 00007fe174051700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000016b9e60 CR3: 000000008f8f0000 CR4: 00000000001406e0 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 entry_SYSCALL_64_after_hwframe+0x46/0xbb DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: RIP: 0033:0x45e219 RSP: 002b:00007f3057547c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00007f3057547ca0 R08: 0000000020000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000027 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 R13: 00007ffe9cbfe39f R14: 00007f30575489c0 R15: 000000000119bf8c __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 Allocated by task 29887: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 p9_idpool_get+0x5f/0xf0 net/9p/util.c:94 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] p9_fid_create+0x47/0x3a0 net/9p/client.c:918 p9_client_attach+0x6d/0x750 net/9p/client.c:1158 v9fs_session_init+0xc03/0x1540 fs/9p/v9fs.c:471 p9_client_prepare_req.part.0+0x65/0xb60 net/9p/client.c:723 v9fs_mount+0x73/0x860 fs/9p/vfs_super.c:135 mount_fs+0x92/0x2a0 fs/super.c:1237 p9_client_prepare_req net/9p/client.c:718 [inline] p9_client_rpc+0x170/0x1520 net/9p/client.c:763 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 29887: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 p9_client_clunk+0x83/0x240 net/9p/client.c:1507 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 v9fs_mount+0x69f/0x860 fs/9p/vfs_super.c:200 p9_client_destroy.cold+0x67/0xaa net/9p/client.c:1121 v9fs_session_close+0x45/0x2c0 fs/9p/v9fs.c:511 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:233 mount_fs+0x92/0x2a0 fs/super.c:1237 deactivate_locked_super+0x6c/0xd0 fs/super.c:319 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 sget_userns+0x9c4/0xc10 fs/super.c:537 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 sget+0xd1/0x110 fs/super.c:572 v9fs_mount+0x9e/0x860 fs/9p/vfs_super.c:141 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88809780b000 which belongs to the cache kmalloc-96 of size 96 RIP: 0033:0x45e219 The buggy address is located 0 bytes inside of 96-byte region [ffff88809780b000, ffff88809780b060) RSP: 002b:00007fe174050c68 EFLAGS: 00000246 The buggy address belongs to the page: ORIG_RAX: 00000000000000a5 page:ffffea00025e02c0 count:1 mapcount:0 mapping:ffff88809780b000 index:0xffff88809780b280 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 flags: 0xfff00000000100(slab) RBP: 00007fe174050ca0 R08: 0000000020000240 R09: 0000000000000000 raw: 00fff00000000100 ffff88809780b000 ffff88809780b280 000000010000001b R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000027 raw: ffffea00026a0e60 ffffea0002c2f320 ffff88813fe804c0 0000000000000000 R13: 00007ffc77158c9f R14: 00007fe1740519c0 R15: 000000000119bf8c page dumped because: kasan: bad access detected Code: 18 Memory state around the buggy address: 00 ffff88809780af00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc 00 ffff88809780af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 00 >ffff88809780b000: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc 00 ^ 48 ffff88809780b080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc 81 ffff88809780b100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc c4 ================================================================== 80 01 00 00 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 2a 00 00 49 81 3c 24 a0 17 2e 8b 0f 84 5f RIP: __lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369 RSP: ffff88808c9cf7a0 ---[ end trace 68ec868b18d5cb88 ]---