================================================================== 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 ffff88808f38a6d0 by task blkid/21201 CPU: 1 PID: 21201 Comm: blkid Not tainted 5.3.0-rc6+ #181 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:filemap_map_pages+0xc3d/0x1360 mm/filemap.c:2683 Code: 85 3c 05 00 00 e8 73 d3 e3 ff be 08 00 00 00 4c 89 ef e8 16 b8 1d 00 f0 49 0f ba 6d 00 00 0f 92 c3 31 ff 89 de e8 93 d4 e3 ff <84> db 0f 85 e6 f8 ff ff e8 46 d3 e3 ff 49 8d 7e 18 48 b9 00 00 00 RSP: 0000:ffff888050e07ba0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffffea0000275200 RCX: ffffffff818ea08d RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888050e07cd0 R08: ffff888096388240 R09: fffff9400004ea41 R10: fffff9400004ea40 R11: ffffea0000275207 R12: ffffea0000275200 R13: ffffea0000275200 R14: ffffea0000275200 R15: ffff888050e07ca8 do_fault_around mm/memory.c:3441 [inline] do_read_fault mm/memory.c:3475 [inline] do_fault mm/memory.c:3609 [inline] handle_pte_fault mm/memory.c:3840 [inline] __handle_mm_fault+0x3241/0x3f20 mm/memory.c:3964 handle_mm_fault+0x1b5/0x6b0 mm/memory.c:4001 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline] __do_page_fault+0x536/0xdd0 arch/x86/mm/fault.c:1506 do_page_fault+0x38/0x590 arch/x86/mm/fault.c:1530 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1202 RIP: 0033:0x7fb504a9fbe0 Code: Bad RIP value. RSP: 002b:00007ffc0f01cd78 EFLAGS: 00010286 RAX: 00007fb504d4f518 RBX: 0000000000000008 RCX: 0000000000000000 RDX: 0000000000000009 RSI: 0000000000402ece RDI: 0000000000000008 RBP: 00007ffc0f01df2b R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 00007fb504a41f20 R12: 0000000000403738 R13: 0000000000000008 R14: 0000000000000000 R15: 0000000000000005 Allocated by task 10233: 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_node mm/slab.c:3262 [inline] kmem_cache_alloc_node+0x138/0x740 mm/slab.c:3574 alloc_task_struct_node kernel/fork.c:160 [inline] dup_task_struct kernel/fork.c:851 [inline] copy_process+0x46d1/0x6b00 kernel/fork.c:1856 _do_fork+0x146/0xfa0 kernel/fork.c:2369 kernel_thread+0xbb/0xf0 kernel/fork.c:2456 call_usermodehelper_exec_sync kernel/umh.c:135 [inline] call_usermodehelper_exec_work+0xc3/0x280 kernel/umh.c:187 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 Freed by task 20970: 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 free_task_struct kernel/fork.c:165 [inline] free_task+0xdd/0x120 kernel/fork.c:464 __put_task_struct+0x202/0x4c0 kernel/fork.c:736 put_task_struct include/linux/sched/task.h:115 [inline] delayed_put_task_struct+0x220/0x370 kernel/exit.c:182 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2114 [inline] rcu_core+0x67f/0x1580 kernel/rcu/tree.c:2314 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323 __do_softirq+0x262/0x98c kernel/softirq.c:292 The buggy address belongs to the object at ffff88808f38a140 which belongs to the cache task_struct of size 6080 The buggy address is located 1424 bytes inside of 6080-byte region [ffff88808f38a140, ffff88808f38b900) The buggy address belongs to the page: page:ffffea00023ce280 refcount:1 mapcount:0 mapping:ffff88821bc428c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002545e08 ffffea00018d8d88 ffff88821bc428c0 raw: 0000000000000000 ffff88808f38a140 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808f38a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808f38a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808f38a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808f38a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808f38a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================