================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 Read of size 4 at addr ffff88806186a610 by task syz-executor.4/29635 CPU: 0 PID: 29635 Comm: syz-executor.4 Not tainted 5.3.0-rc6+ #179 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:618 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] RIP: 0010:compound_head include/linux/page-flags.h:174 [inline] RIP: 0010:PageAnon include/linux/page-flags.h:463 [inline] RIP: 0010:zap_pte_range mm/memory.c:1049 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1161 [inline] RIP: 0010:zap_pud_range mm/memory.c:1190 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1211 [inline] RIP: 0010:unmap_page_range+0xa38/0x2170 mm/memory.c:1232 Code: c0 74 08 3c 01 0f 8e c4 14 00 00 41 80 4d 20 08 4d 85 e4 0f 84 be 04 00 00 e8 64 3e d5 ff 49 8d 44 24 08 48 89 85 28 ff ff ff <48> c1 e8 03 42 80 3c 38 00 0f 85 60 14 00 00 49 8b 44 24 08 31 ff RSP: 0018:ffff88808a2ff730 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffea00026bdc88 RBX: 00007fcf5afc8000 RCX: 800000009af72007 RDX: 0000000000000000 RSI: ffffffff819d357c RDI: ffff88808a2ffa18 RBP: ffff88808a2ff890 R08: ffff88808d7a4140 R09: fffff9400049c1af R10: fffff9400049c1ae R11: ffffea00024e0d73 R12: ffffea00026bdc80 R13: ffff88808a2ffa00 R14: ffff88808a2ffa20 R15: dffffc0000000000 unmap_single_vma+0x19d/0x300 mm/memory.c:1277 unmap_vmas+0x135/0x280 mm/memory.c:1309 exit_mmap+0x2ba/0x530 mm/mmap.c:3145 __mmput kernel/fork.c:1064 [inline] mmput+0x179/0x4d0 kernel/fork.c:1085 exit_mm kernel/exit.c:547 [inline] do_exit+0x84e/0x2e50 kernel/exit.c:866 do_group_exit+0x135/0x360 kernel/exit.c:983 get_signal+0x47c/0x2500 kernel/signal.c:2734 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459879 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fcf59d33cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000075bfd0 RCX: 0000000000459879 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bfd0 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bfd4 R13: 00007fff2b28c59f R14: 00007fcf59d349c0 R15: 000000000075bfd4 Allocated by task 12003: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:493 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:501 slab_post_alloc_hook mm/slab.h:520 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 kmem_cache_zalloc include/linux/slab.h:738 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0xf1/0x41f net/core/net_namespace.c:462 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2831 __do_sys_unshare kernel/fork.c:2899 [inline] __se_sys_unshare kernel/fork.c:2897 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2897 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 372: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 net_free net/core/net_namespace.c:438 [inline] net_drop_ns.part.0+0x70/0x90 net/core/net_namespace.c:445 net_drop_ns net/core/net_namespace.c:444 [inline] cleanup_net+0x774/0xa60 net/core/net_namespace.c:613 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88806186a040 which belongs to the cache net_namespace of size 6784 The buggy address is located 1488 bytes inside of 6784-byte region [ffff88806186a040, ffff88806186bac0) The buggy address belongs to the page: page:ffffea0001861a80 refcount:1 mapcount:0 mapping:ffff8880a9ddd000 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00027a7e88 ffffea0001a3ae08 ffff8880a9ddd000 raw: 0000000000000000 ffff88806186a040 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806186a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806186a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806186a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806186a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806186a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================