Debian GNU/Linux 7 syzkaller ttyS0 [ 31.007517] random: sshd: uninitialized urandom read (32 bytes read) syzkaller login: [ 31.206308] kauditd_printk_skb: 9 callbacks suppressed [ 31.206316] audit: type=1400 audit(1571155341.295:35): avc: denied { map } for pid=6829 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 31.260666] random: sshd: uninitialized urandom read (32 bytes read) [ 31.839099] random: sshd: uninitialized urandom read (32 bytes read) [ 911.216482] audit: type=1400 audit(1571156221.305:36): avc: denied { map } for pid=6839 comm="sh" path="/bin/dash" dev="sda1" ino=1473 scontext=system_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 963.593086] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.84' (ECDSA) to the list of known hosts. [ 969.192198] random: sshd: uninitialized urandom read (32 bytes read) 2019/10/15 16:17:59 parsed 1 programs [ 969.372892] audit: type=1400 audit(1571156279.465:37): avc: denied { map } for pid=6846 comm="syz-execprog" path="/root/syz-execprog" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 969.429936] audit: type=1400 audit(1571156279.515:38): avc: denied { map } for pid=6846 comm="syz-execprog" path="/sys/kernel/debug/kcov" dev="debugfs" ino=29 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:debugfs_t:s0 tclass=file permissive=1 [ 969.991574] random: cc1: uninitialized urandom read (8 bytes read) 2019/10/15 16:18:00 executed programs: 0 [ 971.100946] IPVS: ftp: loaded support on port[0] = 21 [ 971.975015] chnl_net:caif_netlink_parms(): no params data found [ 972.003657] bridge0: port 1(bridge_slave_0) entered blocking state [ 972.010500] bridge0: port 1(bridge_slave_0) entered disabled state [ 972.017483] device bridge_slave_0 entered promiscuous mode [ 972.024321] bridge0: port 2(bridge_slave_1) entered blocking state [ 972.030913] bridge0: port 2(bridge_slave_1) entered disabled state [ 972.037678] device bridge_slave_1 entered promiscuous mode [ 972.051631] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 972.060320] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 972.076990] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 972.084472] team0: Port device team_slave_0 added [ 972.089838] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 972.096960] team0: Port device team_slave_1 added [ 972.102151] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 972.109331] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 972.161779] device hsr_slave_0 entered promiscuous mode [ 972.220311] device hsr_slave_1 entered promiscuous mode [ 972.280445] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 972.287277] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 972.299668] bridge0: port 2(bridge_slave_1) entered blocking state [ 972.306098] bridge0: port 2(bridge_slave_1) entered forwarding state [ 972.312959] bridge0: port 1(bridge_slave_0) entered blocking state [ 972.319315] bridge0: port 1(bridge_slave_0) entered forwarding state [ 972.344119] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 972.350976] 8021q: adding VLAN 0 to HW filter on device bond0 [ 972.358307] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 972.366425] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 972.386352] bridge0: port 1(bridge_slave_0) entered disabled state [ 972.393717] bridge0: port 2(bridge_slave_1) entered disabled state [ 972.403382] IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready [ 972.409444] 8021q: adding VLAN 0 to HW filter on device team0 [ 972.417505] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 972.425540] bridge0: port 1(bridge_slave_0) entered blocking state [ 972.431908] bridge0: port 1(bridge_slave_0) entered forwarding state [ 972.440534] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 972.448112] bridge0: port 2(bridge_slave_1) entered blocking state [ 972.454500] bridge0: port 2(bridge_slave_1) entered forwarding state [ 972.466449] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 972.475166] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 972.487496] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network [ 972.497806] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network [ 972.508539] IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready [ 972.515519] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 972.523277] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 972.530919] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 972.538613] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 972.549211] IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready [ 972.558559] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 972.970837] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 973.720654] hrtimer: interrupt took 25303 ns [ 973.865181] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 974.561763] l2tp_core: tunl 4: sockfd_lookup(fd=5) returned -9 [ 974.784933] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 974.903931] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:05 executed programs: 107 [ 975.803180] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 976.457880] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 977.553875] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 978.075337] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 979.706111] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 980.121593] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 980.264259] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 980.469824] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:10 executed programs: 356 [ 981.497504] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 984.131799] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 984.256403] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 984.360470] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 984.783773] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:15 executed programs: 607 [ 988.030764] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 988.270883] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 988.353716] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 988.474249] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 990.244516] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 990.484003] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:20 executed programs: 854 [ 992.854836] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 993.034624] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 993.991395] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 995.006083] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 995.448258] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 995.783693] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:26 executed programs: 1108 [ 996.733662] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 997.695111] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 998.114288] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 2019/10/15 16:18:31 executed programs: 1364 [ 1000.946009] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 1003.062703] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 1003.341763] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 1003.504089] l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 [ 1004.740777] ================================================================== [ 1004.748524] BUG: KASAN: use-after-free in l2tp_session_create+0x1439/0x1600 [ 1004.755687] Read of size 4 at addr ffff88808b23e018 by task syz-executor.0/14287 [ 1004.763239] [ 1004.764858] CPU: 1 PID: 14287 Comm: syz-executor.0 Not tainted 4.14.149 #0 [ 1004.771857] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1004.781201] Call Trace: [ 1004.783835] dump_stack+0x138/0x197 [ 1004.787454] ? l2tp_session_create+0x1439/0x1600 [ 1004.792251] print_address_description.cold+0x7c/0x1dc [ 1004.797514] ? l2tp_session_create+0x1439/0x1600 [ 1004.802335] kasan_report.cold+0xa9/0x2af [ 1004.806472] __asan_report_load4_noabort+0x14/0x20 [ 1004.811391] l2tp_session_create+0x1439/0x1600 [ 1004.815966] ? trace_hardirqs_on_caller+0x400/0x590 [ 1004.821009] ? l2tp_session_get+0x16d/0x690 [ 1004.825408] ? trace_hardirqs_on+0xd/0x10 [ 1004.829573] pppol2tp_connect+0x11bf/0x18b0 [ 1004.833916] ? pppol2tp_seq_show+0xbc0/0xbc0 [ 1004.838312] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 1004.843108] ? retint_kernel+0x2d/0x2d [ 1004.847017] SYSC_connect+0x1f6/0x2d0 [ 1004.850807] ? SYSC_bind+0x220/0x220 [ 1004.854516] ? SyS_clock_gettime+0xf8/0x180 [ 1004.858826] SyS_connect+0x24/0x30 [ 1004.862354] ? SyS_accept+0x30/0x30 [ 1004.865968] do_syscall_64+0x1e8/0x640 [ 1004.869841] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 1004.874674] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 1004.879849] RIP: 0033:0x459a59 [ 1004.883025] RSP: 002b:00007f372b0ffc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 1004.890718] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59 [ 1004.897975] RDX: 0000000000000026 RSI: 0000000020000180 RDI: 0000000000000005 [ 1004.905270] RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 [ 1004.912525] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f372b1006d4 [ 1004.919779] R13: 00000000004c0006 R14: 00000000004d2298 R15: 00000000ffffffff [ 1004.927042] [ 1004.928658] Allocated by task 14287: [ 1004.932362] save_stack_trace+0x16/0x20 [ 1004.936319] save_stack+0x45/0xd0 [ 1004.939763] kasan_kmalloc+0xce/0xf0 [ 1004.943464] __kmalloc+0x15d/0x7a0 [ 1004.946989] l2tp_session_create+0x38/0x1600 [ 1004.951393] pppol2tp_connect+0x11bf/0x18b0 [ 1004.955701] SYSC_connect+0x1f6/0x2d0 [ 1004.959520] SyS_connect+0x24/0x30 [ 1004.963048] do_syscall_64+0x1e8/0x640 [ 1004.966921] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 1004.972123] [ 1004.973733] Freed by task 14289: [ 1004.977104] save_stack_trace+0x16/0x20 [ 1004.981059] save_stack+0x45/0xd0 [ 1004.984497] kasan_slab_free+0x75/0xc0 [ 1004.988366] kfree+0xcc/0x270 [ 1004.991455] l2tp_session_free+0x176/0x210 [ 1004.995686] l2tp_tunnel_closeall+0x2ca/0x380 [ 1005.000167] l2tp_udp_encap_destroy+0x99/0x100 [ 1005.004777] udpv6_destroy_sock+0xb3/0xd0 [ 1005.008919] sk_common_release+0x6b/0x310 [ 1005.013053] udp_lib_close+0x16/0x20 [ 1005.016771] inet_release+0xec/0x1c0 [ 1005.020539] inet6_release+0x53/0x80 [ 1005.024239] __sock_release+0xce/0x2b0 [ 1005.028113] sock_close+0x1b/0x30 [ 1005.031550] __fput+0x275/0x7a0 [ 1005.034819] ____fput+0x16/0x20 [ 1005.038084] task_work_run+0x114/0x190 [ 1005.041978] exit_to_usermode_loop+0x1da/0x220 [ 1005.046560] do_syscall_64+0x4bc/0x640 [ 1005.050484] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 1005.055823] [ 1005.057446] The buggy address belongs to the object at ffff88808b23e000 [ 1005.057446] which belongs to the cache kmalloc-512 of size 512 [ 1005.070091] The buggy address is located 24 bytes inside of [ 1005.070091] 512-byte region [ffff88808b23e000, ffff88808b23e200) [ 1005.081868] The buggy address belongs to the page: [ 1005.086823] page:ffffea00022c8f80 count:1 mapcount:0 mapping:ffff88808b23e000 index:0x0 [ 1005.094952] flags: 0x1fffc0000000100(slab) [ 1005.099175] raw: 01fffc0000000100 ffff88808b23e000 0000000000000000 0000000100000006 [ 1005.107045] raw: ffffea00026df7a0 ffffea000265a7a0 ffff8880aa800940 0000000000000000 [ 1005.114912] page dumped because: kasan: bad access detected [ 1005.120608] [ 1005.122222] Memory state around the buggy address: [ 1005.127139] ffff88808b23df00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1005.134484] ffff88808b23df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1005.141868] >ffff88808b23e000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1005.149213] ^ [ 1005.153348] ffff88808b23e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1005.160692] ffff88808b23e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1005.168031] ================================================================== [ 1005.175373] Disabling lock debugging due to kernel taint [ 1005.181826] Kernel panic - not syncing: panic_on_warn set ... [ 1005.181826] [ 1005.189299] CPU: 1 PID: 14287 Comm: syz-executor.0 Tainted: G B 4.14.149 #0 [ 1005.197510] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 1005.206846] Call Trace: [ 1005.209456] dump_stack+0x138/0x197 [ 1005.213067] ? l2tp_session_create+0x1439/0x1600 [ 1005.217824] panic+0x1f2/0x426 [ 1005.221045] ? add_taint.cold+0x16/0x16 [ 1005.225008] ? ___preempt_schedule+0x16/0x18 [ 1005.229406] kasan_end_report+0x47/0x4f [ 1005.233490] kasan_report.cold+0x130/0x2af [ 1005.237756] __asan_report_load4_noabort+0x14/0x20 [ 1005.242674] l2tp_session_create+0x1439/0x1600 [ 1005.247274] ? trace_hardirqs_on_caller+0x400/0x590 [ 1005.252283] ? l2tp_session_get+0x16d/0x690 [ 1005.256593] ? trace_hardirqs_on+0xd/0x10 [ 1005.260729] pppol2tp_connect+0x11bf/0x18b0 [ 1005.265039] ? pppol2tp_seq_show+0xbc0/0xbc0 [ 1005.269432] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 1005.274176] ? retint_kernel+0x2d/0x2d [ 1005.278049] SYSC_connect+0x1f6/0x2d0 [ 1005.281837] ? SYSC_bind+0x220/0x220 [ 1005.285575] ? SyS_clock_gettime+0xf8/0x180 [ 1005.289879] SyS_connect+0x24/0x30 [ 1005.293404] ? SyS_accept+0x30/0x30 [ 1005.297015] do_syscall_64+0x1e8/0x640 [ 1005.300931] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 1005.305759] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 1005.310964] RIP: 0033:0x459a59 [ 1005.314135] RSP: 002b:00007f372b0ffc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 1005.321828] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59 [ 1005.329118] RDX: 0000000000000026 RSI: 0000000020000180 RDI: 0000000000000005 [ 1005.336371] RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 [ 1005.343711] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f372b1006d4 [ 1005.351075] R13: 00000000004c0006 R14: 00000000004d2298 R15: 00000000ffffffff [ 1005.360037] Kernel Offset: disabled [ 1005.363673] Rebooting in 86400 seconds..