================================================================== 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 ffff88806c254750 by task udevd/3908 CPU: 0 PID: 3908 Comm: udevd Not tainted 5.3.0-rc3+ #165 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:612 __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:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline] RIP: 0010:console_unlock+0xbc7/0xf10 kernel/printk/printk.c:2471 Code: d2 88 48 c1 e8 03 42 80 3c 30 00 0f 85 e4 02 00 00 48 83 3d 5a 1a 77 07 00 0f 84 91 01 00 00 e8 af b0 16 00 48 8b 7d 98 57 9d <0f> 1f 44 00 00 e9 6d ff ff ff e8 9a b0 16 00 48 8b 7d 08 c7 05 dc RSP: 0018:ffff88809648f958 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8880964845c0 RBX: 0000000000000200 RCX: 1ffffffff134b566 RDX: 0000000000000000 RSI: ffffffff815bd8c1 RDI: 0000000000000293 RBP: ffff88809648f9e0 R08: ffff8880964845c0 R09: fffffbfff134af28 R10: fffffbfff134af27 R11: ffffffff89a5793f R12: 0000000000000000 R13: ffffffff84335f70 R14: dffffc0000000000 R15: ffffffff893ca250 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1986 vprintk_default+0x28/0x30 kernel/printk/printk.c:2013 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386 printk+0xba/0xed kernel/printk/printk.c:2046 kobject_uevent_env+0xe2/0x101d lib/kobject_uevent.c:476 kobject_synth_uevent.cold+0xa0/0x100 lib/kobject_uevent.c:208 uevent_store+0x25/0x60 drivers/base/core.c:1244 dev_attr_store+0x57/0x80 drivers/base/core.c:947 sysfs_kf_write+0x116/0x170 fs/sysfs/file.c:138 kernfs_fop_write+0x2b8/0x480 fs/kernfs/file.c:315 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f0ebe811370 Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24 RSP: 002b:00007ffc1dd7ac38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000f854c0 RCX: 00007f0ebe811370 RDX: 0000000000000006 RSI: 000000000041f4f9 RDI: 000000000000000b RBP: 0000000000f8b1b0 R08: 000000000041f4f1 R09: 00007f0ebe8677d0 R10: 7269762f73656369 R11: 0000000000000246 R12: 000000000000000b R13: 0000000000000000 R14: 0000000000f854c0 R15: 0000000000f7a250 Allocated by task 9759: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:487 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:495 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 __do_sys_clone kernel/fork.c:2524 [inline] __se_sys_clone kernel/fork.c:2505 [inline] __x64_sys_clone+0x18d/0x250 kernel/fork.c:2505 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 16: 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:449 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457 __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 ffff88806c254640 which belongs to the cache task_struct of size 6080 The buggy address is located 272 bytes inside of 6080-byte region [ffff88806c254640, ffff88806c255e00) The buggy address belongs to the page: page:ffffea0001b09500 refcount:1 mapcount:0 mapping:ffff88821bc428c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001c12c88 ffffea0001a99e88 ffff88821bc428c0 raw: 0000000000000000 ffff88806c254640 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806c254600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88806c254680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806c254700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806c254780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806c254800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================