vxfs: unable to read disk superblock at 8 audit: type=1804 audit(1614538416.893:357): pid=27204 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir189470791/syzkaller.EpNQrG/329/bus" dev="sda1" ino=16885 res=1 vxfs: can't find superblock. ================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x245f/0x28c0 net/ipv4/tcp_timer.c:471 Read of size 8 at addr ffff88804345c438 by task kauditd/1937 CPU: 1 PID: 1937 Comm: kauditd Not tainted 4.14.222-syzkaller #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+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_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 tcp_retransmit_timer+0x245f/0x28c0 net/ipv4/tcp_timer.c:471 tcp_write_timer_handler+0x434/0x780 net/ipv4/tcp_timer.c:583 tcp_write_timer+0xc8/0x160 net/ipv4/tcp_timer.c:601 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:console_unlock+0xbeb/0xf20 kernel/printk/printk.c:2408 RSP: 0018:ffff8880b10ffc30 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff10 RAX: ffff8880b110c180 RBX: 0000000000000200 RCX: 1ffff11016221945 RDX: 0000000000000000 RSI: ffff8880b110ca08 RDI: 0000000000000297 RBP: 0000000000000000 R08: ffffffff8b9b5f38 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff83d096a0 R13: ffffffff8961dc90 R14: dffffc0000000000 R15: 00000000000000fc vprintk_emit+0x224/0x620 kernel/printk/printk.c:1923 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 kauditd_printk_skb kernel/audit.c:506 [inline] kauditd_hold_skb.cold+0x3e/0x4d kernel/audit.c:539 kauditd_send_queue+0xfb/0x140 kernel/audit.c:702 kauditd_thread+0x4a5/0x630 kernel/audit.c:828 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 11201: 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 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552 kmem_cache_zalloc include/linux/slab.h:651 [inline] net_alloc net/core/net_namespace.c:362 [inline] copy_net_ns+0xf7/0x440 net/core/net_namespace.c:402 create_new_namespaces+0x375/0x720 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xa1/0x1d0 kernel/nsproxy.c:206 SYSC_unshare kernel/fork.c:2412 [inline] SyS_unshare+0x308/0x7f0 kernel/fork.c:2362 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 9313: 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 __cache_free mm/slab.c:3496 [inline] kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758 net_free net/core/net_namespace.c:378 [inline] net_drop_ns+0x63/0x70 net/core/net_namespace.c:385 cleanup_net+0x526/0x840 net/core/net_namespace.c:502 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 The buggy address belongs to the object at ffff88804345c240 which belongs to the cache net_namespace of size 8832 The buggy address is located 504 bytes inside of 8832-byte region [ffff88804345c240, ffff88804345e4c0) The buggy address belongs to the page: page:ffffea00010d1700 count:1 mapcount:0 mapping:ffff88804345c240 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffff88804345c240 0000000000000000 0000000100000001 raw: ffffea000136de20 ffffea0002705e20 ffff88823f8bbc80 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804345c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804345c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804345c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804345c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804345c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================