================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2b80/0x2f20 net/ipv4/tcp_timer.c:480 Read of size 8 at addr ffff8880915604f8 by task syz-executor.3/11419 CPU: 1 PID: 11419 Comm: syz-executor.3 Not tainted 5.2.0-rc1+ #6 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+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 tcp_retransmit_timer+0x2b80/0x2f20 net/ipv4/tcp_timer.c:480 tcp_write_timer_handler+0x591/0x8a0 net/ipv4/tcp_timer.c:591 tcp_write_timer+0x10e/0x1d0 net/ipv4/tcp_timer.c:611 call_timer_fn+0x193/0x720 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+0x66f/0x1740 kernel/time/timer.c:1698 __do_softirq+0x25c/0x94c kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:lock_acquire+0x1ea/0x3f0 kernel/locking/lockdep.c:4306 Code: 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 c4 01 00 00 48 83 3d 32 05 5b 07 00 0f 84 38 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b RSP: 0018:ffff88806d64f6d0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1164e0e RBX: ffff888091188140 RCX: 0000000000005740 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff88806d64f718 R08: 00000000c4ce8a40 R09: ffff888091188a58 R10: ffff888091188a38 R11: ffff888091188140 R12: ffffffff88c398a0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 __fs_reclaim_acquire mm/page_alloc.c:4005 [inline] fs_reclaim_acquire.part.0+0x24/0x30 mm/page_alloc.c:4016 fs_reclaim_acquire mm/page_alloc.c:4596 [inline] prepare_alloc_pages mm/page_alloc.c:4593 [inline] __alloc_pages_nodemask+0x4f5/0x8d0 mm/page_alloc.c:4645 alloc_pages_current+0x107/0x210 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] __get_free_pages mm/page_alloc.c:4701 [inline] get_zeroed_page+0x14/0x50 mm/page_alloc.c:4710 pud_alloc_one arch/x86/include/asm/pgalloc.h:169 [inline] __pud_alloc+0x3b/0x250 mm/memory.c:4106 pud_alloc+0xde/0x150 include/linux/mm.h:1910 copy_pud_range mm/memory.c:922 [inline] copy_p4d_range mm/memory.c:964 [inline] copy_page_range+0x383/0x1fc0 mm/memory.c:1026 dup_mmap kernel/fork.c:588 [inline] dup_mm+0x9c4/0x13b0 kernel/fork.c:1341 copy_mm kernel/fork.c:1397 [inline] copy_process.part.0+0x2cde/0x6790 kernel/fork.c:2032 copy_process kernel/fork.c:1800 [inline] _do_fork+0x25d/0xfe0 kernel/fork.c:2369 __do_sys_clone kernel/fork.c:2476 [inline] __se_sys_clone kernel/fork.c:2470 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2470 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45784a Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007fffa9a32cd0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fffa9a32cd0 RCX: 000000000045784a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fffa9a32d10 R08: 0000000000000001 R09: 0000555556e8e940 R10: 0000555556e8ec10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fffa9a32d60 Allocated by task 11416: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 kmem_cache_zalloc include/linux/slab.h:732 [inline] net_alloc net/core/net_namespace.c:386 [inline] copy_net_ns+0xed/0x340 net/core/net_namespace.c:426 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2692 __do_sys_unshare kernel/fork.c:2760 [inline] __se_sys_unshare kernel/fork.c:2758 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2758 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2629: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 net_free net/core/net_namespace.c:402 [inline] net_drop_ns.part.0+0x70/0x90 net/core/net_namespace.c:409 net_drop_ns net/core/net_namespace.c:408 [inline] cleanup_net+0x538/0x960 net/core/net_namespace.c:571 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8880915602c0 which belongs to the cache net_namespace of size 8640 The buggy address is located 568 bytes inside of 8640-byte region [ffff8880915602c0, ffff888091562480) The buggy address belongs to the page: page:ffffea0002455800 refcount:1 mapcount:0 mapping:ffff88821b6f60c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001ac8f08 ffffea0001aee008 ffff88821b6f60c0 raw: 0000000000000000 ffff8880915602c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091560380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888091560400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888091560480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888091560500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888091560580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================