NILFS (loop2): unable to fall back to spare super block NILFS (loop2): error -22 while searching super root ================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485 Read of size 8 at addr ffff888031890f78 by task syz-executor.4/24265 CPU: 0 PID: 24265 Comm: syz-executor.4 Not tainted 4.19.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485 tcp_write_timer_handler+0x5e6/0xa60 net/ipv4/tcp_timer.c:598 tcp_write_timer+0x103/0x1b0 net/ipv4/tcp_timer.c:618 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1092 do_softirq.part.0+0x160/0x1c0 kernel/softirq.c:336 F2FS-fs (loop3): Unable to read 2th superblock do_softirq kernel/softirq.c:328 [inline] __local_bh_enable_ip+0x20e/0x270 kernel/softirq.c:189 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:1929 [inline] nf_ct_iterate_cleanup+0x239/0x520 net/netfilter/nf_conntrack_core.c:1952 F2FS-fs (loop3): Unable to read 2th superblock nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2037 [inline] nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2022 masq_device_event+0xd6/0x110 net/ipv4/netfilter/nf_nat_masquerade_ipv4.c:100 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 call_netdevice_notifiers net/core/dev.c:1762 [inline] dev_close_many+0x323/0x670 net/core/dev.c:1514 rollback_registered_many+0x2f7/0xe70 net/core/dev.c:8165 rollback_registered+0xe9/0x1b0 net/core/dev.c:8230 unregister_netdevice_queue+0x1de/0x3e0 net/core/dev.c:9297 unregister_netdevice include/linux/netdevice.h:2615 [inline] __tun_detach+0x100d/0x1320 drivers/net/tun.c:737 tun_detach drivers/net/tun.c:754 [inline] tun_chr_close+0xd9/0x180 drivers/net/tun.c:3275 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466459 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0ec7b98218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056bf68 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68 RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 00007fffb21434af R14: 00007f0ec7b98300 R15: 0000000000022000 Allocated by task 9687: kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 kmem_cache_zalloc include/linux/slab.h:699 [inline] net_alloc net/core/net_namespace.c:385 [inline] copy_net_ns+0x106/0x340 net/core/net_namespace.c:425 create_new_namespaces+0x3f6/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x36c/0x9a0 kernel/fork.c:2541 __do_sys_unshare kernel/fork.c:2609 [inline] __se_sys_unshare kernel/fork.c:2607 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:2607 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9376: __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x7f/0x260 mm/slab.c:3765 net_free net/core/net_namespace.c:401 [inline] net_drop_ns+0x73/0x90 net/core/net_namespace.c:408 cleanup_net+0x64c/0x8b0 net/core/net_namespace.c:571 process_one_work+0x864/0x1570 kernel/workqueue.c:2152 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff888031890d40 which belongs to the cache net_namespace of size 8640 The buggy address is located 568 bytes inside of 8640-byte region [ffff888031890d40, ffff888031892f00) The buggy address belongs to the page: page:ffffea0000c62400 count:1 mapcount:0 mapping:ffff88823b843e00 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0000ec8808 ffffea00027a7708 ffff88823b843e00 raw: 0000000000000000 ffff888031890d40 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888031890e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888031890e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888031890f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888031890f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888031891000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================