audit: type=1326 audit(1517486258.882:17): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=6383 comm="syz-executor0" exe="/root/syz-executor0" sig=31 arch=40000003 syscall=240 compat=1 ip=0xf77daba9 code=0x0 ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:218 [inline] BUG: KASAN: use-after-free in atomic_read arch/x86/include/asm/atomic.h:27 [inline] BUG: KASAN: use-after-free in __atomic_add_unless arch/x86/include/asm/atomic.h:212 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:437 [inline] BUG: KASAN: use-after-free in sk_dst_get include/net/sock.h:1741 [inline] BUG: KASAN: use-after-free in pppol2tp_connect+0x1631/0x1930 net/l2tp/l2tp_ppp.c:755 Read of size 4 at addr ffff8800a86eaa80 by task syz-executor2/6411 CPU: 0 PID: 6411 Comm: syz-executor2 Not tainted 4.4.114-gfe09418 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 4c2351065e752966 ffff8800b9e2fab0 ffffffff81d02e6d ffffea0002a1ba80 ffff8800a86eaa80 0000000000000000 ffff8800a86eaa80 1ffff100173c5f73 ffff8800b9e2fae8 ffffffff814fd6f3 ffff8800a86eaa80 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x73/0x260 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x285/0x370 mm/kasan/report.c:408 [] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428 [] __read_once_size include/linux/compiler.h:218 [inline] [] atomic_read arch/x86/include/asm/atomic.h:27 [inline] [] __atomic_add_unless arch/x86/include/asm/atomic.h:212 [inline] [] atomic_add_unless include/linux/atomic.h:437 [inline] [] sk_dst_get include/net/sock.h:1741 [inline] [] pppol2tp_connect+0x1631/0x1930 net/l2tp/l2tp_ppp.c:755 [] SYSC_connect+0x1b6/0x310 net/socket.c:1557 [] SyS_connect+0x24/0x30 net/socket.c:1538 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 6350: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc+0xba/0x290 mm/slub.c:2628 [] dst_alloc+0x11f/0x1a0 net/core/dst.c:210 [] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1467 [] __mkroute_output net/ipv4/route.c:2120 [inline] [] __ip_route_output_key_hash+0xa4e/0x2390 net/ipv4/route.c:2332 [] __ip_route_output_key include/net/route.h:123 [inline] [] ip_route_output_flow+0x29/0xa0 net/ipv4/route.c:2418 [] ip_route_connect include/net/route.h:303 [inline] [] __ip4_datagram_connect+0x652/0x1150 net/ipv4/datagram.c:51 [] __ip6_datagram_connect+0x1401/0x1950 net/ipv6/datagram.c:105 [] ip6_datagram_connect+0x2f/0x50 net/ipv6/datagram.c:223 [] inet_dgram_connect+0x16b/0x1f0 net/ipv4/af_inet.c:550 [] SYSC_connect+0x1b6/0x310 net/socket.c:1557 [] SyS_connect+0x24/0x30 net/socket.c:1538 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Freed by task 4131: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kmem_cache_free+0xc7/0x320 mm/slub.c:2881 [] dst_destroy+0x20e/0x330 net/core/dst.c:270 [] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2705 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline] [] rcu_process_callbacks+0x7f4/0x14a0 kernel/rcu/tree.c:2957 [] __do_softirq+0x227/0xa38 kernel/softirq.c:273 The buggy address belongs to the object at ffff8800a86eaa00 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 128 bytes inside of 208-byte region [ffff8800a86eaa00, ffff8800a86eaad0) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.114-gfe09418 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d9b497c0 task.stack: ffff8801d9b58000 RIP: 0010:[] [] rb_set_parent_color include/linux/rbtree_augmented.h:117 [inline] RIP: 0010:[] [] ____rb_erase_color lib/rbtree.c:256 [inline] RIP: 0010:[] [] rb_erase+0x55d/0x1b60 lib/rbtree.c:429 RSP: 0018:ffff8801db307d38 EFLAGS: 00010086 RAX: ffff8801db319c48 RBX: ffff8801db319c40 RCX: 0000000000000000 RDX: ffffed003b6632e2 RSI: ffff8801db319710 RDI: 1ffff100172eaf6c RBP: ffff8801db307d80 R08: 1ffff10038bfc050 R09: 0000000000000001 R10: 0000000000000000 R11: 1ffff1003b660f6a R12: dffffc0000000000 R13: ffff8800b9757b50 R14: 0000000000000000 R15: ffff8801db319c41 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcb5259fe8 CR3: 00000001c77f4000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8801d835fd28 ffff8801d9b497c0 ffffed003b369406 ffffffff842bdb20 ffff8801d835fd28 ffff8801db319710 ffff8801db319718 0000000000000000 0000000000000000 ffff8801db307db0 ffffffff81d20948 ffffffff842bdb20 Call Trace: [] timerqueue_del+0x78/0x170 lib/timerqueue.c:86 [] __remove_hrtimer+0x90/0x250 kernel/time/hrtimer.c:916 [] __run_hrtimer kernel/time/hrtimer.c:1236 [inline] [] __hrtimer_run_queues+0x238/0xfe0 kernel/time/hrtimer.c:1319 [] hrtimer_interrupt+0x1a6/0x440 kernel/time/hrtimer.c:1353 [] local_apic_timer_interrupt+0x6a/0xb0 arch/x86/kernel/apic/apic.c:901 [] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:925 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:737 [] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291 [] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282 [] default_idle_call+0x48/0x70 kernel/sched/idle.c:93 [] cpuidle_idle_call kernel/sched/idle.c:157 [inline] [] cpu_idle_loop kernel/sched/idle.c:253 [inline] [] cpu_startup_entry+0x5fd/0x8f0 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: 11 00 00 48 89 cf 4c 89 73 08 48 c1 ef 03 42 80 3c 27 00 0f 85 25 11 00 00 4c 89 f1 49 89 df 49 89 5d 10 48 c1 e9 03 49 83 cf 01 <42> 80 3c 21 00 0f 85 e3 10 00 00 48 89 d9 4d 89 3e 48 c1 e9 03 RIP [] rb_set_parent_color include/linux/rbtree_augmented.h:117 [inline] RIP [] ____rb_erase_color lib/rbtree.c:256 [inline] RIP [] rb_erase+0x55d/0x1b60 lib/rbtree.c:429 RSP ---[ end trace 4911231c909bb204 ]---