================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff8880758fd118 by task syz-executor.0/11407 CPU: 1 PID: 11407 Comm: syz-executor.0 Not tainted 5.15.110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:arch_atomic64_try_cmpxchg arch/x86/include/asm/atomic64_64.h:190 [inline] RIP: 0010:arch_atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-long.h:443 [inline] RIP: 0010:atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1669 [inline] RIP: 0010:rwsem_write_trylock kernel/locking/rwsem.c:255 [inline] RIP: 0010:__down_write_common kernel/locking/rwsem.c:1283 [inline] RIP: 0010:__down_write kernel/locking/rwsem.c:1293 [inline] RIP: 0010:down_write+0xd9/0x170 kernel/locking/rwsem.c:1542 Code: a6 f7 48 c7 44 24 20 00 00 00 00 4c 89 ef be 08 00 00 00 e8 19 65 a6 f7 4c 89 f7 be 08 00 00 00 e8 0c 65 a6 f7 42 80 3c 3b 00 <74> 08 4c 89 f7 e8 5d 63 a6 f7 48 8b 44 24 20 b9 01 00 00 00 f0 49 RSP: 0018:ffffc90002f8f000 EFLAGS: 00000246 RAX: 1a9322131e0f5301 RBX: 1ffff920005f1e04 RCX: ffffffff8a22d544 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc90002f8f020 RBP: ffffc90002f8f090 R08: dffffc0000000000 R09: fffff520005f1e05 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005f1e00 R13: ffffffff8ca4d5e0 R14: ffffc90002f8f020 R15: dffffc0000000000 kernfs_drain fs/kernfs/dir.c:494 [inline] __kernfs_remove+0x75b/0xc80 fs/kernfs/dir.c:1358 kernfs_remove_by_name_ns+0x91/0x100 fs/kernfs/dir.c:1552 kernfs_remove_by_name include/linux/kernfs.h:598 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfa/0x2a0 fs/sysfs/group.c:289 sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:313 device_remove_groups drivers/base/core.c:2480 [inline] device_remove_attrs+0xc2/0x140 drivers/base/core.c:2680 device_del+0x6da/0xbd0 drivers/base/core.c:3581 unregister_netdevice_many+0x13a6/0x18f0 net/core/dev.c:11092 unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10998 unregister_netdevice include/linux/netdevice.h:3012 [inline] lapbeth_free_device drivers/net/wan/lapbether.c:434 [inline] lapbeth_device_event+0x7d1/0x950 drivers/net/wan/lapbether.c:469 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:1998 [inline] call_netdevice_notifiers_extack net/core/dev.c:2010 [inline] call_netdevice_notifiers net/core/dev.c:2024 [inline] unregister_netdevice_many+0xf1b/0x18f0 net/core/dev.c:11065 unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10998 unregister_netdevice include/linux/netdevice.h:3012 [inline] nsim_destroy+0x44/0x140 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x153/0x1b0 drivers/net/netdevsim/dev.c:1352 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1365 [inline] nsim_dev_reload_destroy+0x15e/0x240 drivers/net/netdevsim/dev.c:1564 nsim_dev_remove+0x59/0x100 drivers/net/netdevsim/dev.c:1580 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x4cb/0x7f0 drivers/base/dd.c:1262 bus_remove_device+0x2e5/0x400 drivers/base/bus.c:529 device_del+0x6e2/0xbd0 drivers/base/core.c:3582 device_unregister+0x1c/0xc0 drivers/base/core.c:3615 nsim_bus_dev_del drivers/net/netdevsim/bus.c:454 [inline] del_device_store+0x321/0x470 drivers/net/netdevsim/bus.c:354 kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2103 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacf/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd1ab59ceef Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007ffd4e68c100 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fd1ab59ceef RDX: 0000000000000001 RSI: 00007ffd4e68c150 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007ffd4e68c0a0 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fd1ab6468b6 R13: 00007ffd4e68c150 R14: 0000000000000000 R15: 00007ffd4e68c820 Allocated by task 10055: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 1242: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff8880758fcec0 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff8880758fcec0, ffff8880758fe800) The buggy address belongs to the page: page:ffffea0001d63e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880758fb480 pfn:0x758f8 head:ffffea0001d63e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880159ec441 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00008fde00 0000000200000002 ffff888011dc63c0 raw: ffff8880758fb480 0000000080040003 00000001ffffffff ffff8880159ec441 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4425, ts 150606339395, free_ts 150581915326 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 copy_namespaces+0x365/0x3b0 kernel/nsproxy.c:178 copy_process+0x1841/0x3ef0 kernel/fork.c:2201 kernel_clone+0x210/0x960 kernel/fork.c:2601 __do_sys_clone kernel/fork.c:2718 [inline] __se_sys_clone kernel/fork.c:2702 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2702 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 vm_area_dup+0x1e/0xb0 kernel/fork.c:357 __split_vma+0xb4/0x4a0 mm/mmap.c:2729 mprotect_fixup+0x675/0x7d0 mm/mprotect.c:477 do_mprotect_pkey+0x75b/0xa50 mm/mprotect.c:636 __do_sys_mprotect mm/mprotect.c:662 [inline] __se_sys_mprotect mm/mprotect.c:659 [inline] __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:659 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff8880758fd000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880758fd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880758fd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880758fd180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880758fd200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: a6 cmpsb %es:(%rdi),%ds:(%rsi) 1: f7 48 c7 44 24 20 00 testl $0x202444,-0x39(%rax) 8: 00 00 add %al,(%rax) a: 00 4c 89 ef add %cl,-0x11(%rcx,%rcx,4) e: be 08 00 00 00 mov $0x8,%esi 13: e8 19 65 a6 f7 callq 0xf7a66531 18: 4c 89 f7 mov %r14,%rdi 1b: be 08 00 00 00 mov $0x8,%esi 20: e8 0c 65 a6 f7 callq 0xf7a66531 25: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1) * 2a: 74 08 je 0x34 <-- trapping instruction 2c: 4c 89 f7 mov %r14,%rdi 2f: e8 5d 63 a6 f7 callq 0xf7a66391 34: 48 8b 44 24 20 mov 0x20(%rsp),%rax 39: b9 01 00 00 00 mov $0x1,%ecx 3e: f0 lock 3f: 49 rex.WB