[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 42.461169] can: request_module (can-proto-0) failed. [ 42.466397] can: request_module (can-proto-0) failed. [ 43.200131] IPVS: ftp: loaded support on port[0] = 21 [ 43.810348] 8021q: adding VLAN 0 to HW filter on device bond0 [ 43.877443] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 44.154955] tipc: TX() has been purged, node left! [ 45.566086] bond0 (unregistering): Released all slaves Warning: Permanently added '10.128.15.222' (ECDSA) to the list of known hosts. 2019/12/10 15:05:02 parsed 1 programs 2019/12/10 15:05:02 executed programs: 0 [ 50.814360] IPVS: ftp: loaded support on port[0] = 21 [ 50.822588] IPVS: ftp: loaded support on port[0] = 21 [ 50.834420] IPVS: ftp: loaded support on port[0] = 21 [ 50.838320] IPVS: ftp: loaded support on port[0] = 21 [ 50.843268] IPVS: ftp: loaded support on port[0] = 21 [ 50.851324] IPVS: ftp: loaded support on port[0] = 21 [ 51.170607] ================================================================== [ 51.178070] BUG: KASAN: use-after-free in __list_del_entry_valid+0xe7/0xf3 [ 51.185082] Read of size 8 at addr ffff8881d00d61e8 by task syz-executor2/4237 [ 51.192552] [ 51.194162] CPU: 1 PID: 4237 Comm: syz-executor2 Not tainted 5.5.0-rc1-syzkaller #0 [ 51.201934] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.211381] Call Trace: [ 51.213967] dump_stack+0x12f/0x187 [ 51.217575] ? __list_del_entry_valid+0xe7/0xf3 [ 51.222225] print_address_description.constprop.8+0x3b/0x60 [ 51.228004] ? __list_del_entry_valid+0xe7/0xf3 [ 51.232652] ? __list_del_entry_valid+0xe7/0xf3 [ 51.237302] __kasan_report.cold.11+0x1b/0x39 [ 51.241793] ? __list_del_entry_valid+0xe7/0xf3 [ 51.246469] kasan_report+0x12/0x20 [ 51.250080] __asan_report_load8_noabort+0x14/0x20 [ 51.254990] __list_del_entry_valid+0xe7/0xf3 [ 51.259467] cma_cancel_operation+0x2f7/0x9c0 [ 51.263947] rdma_destroy_id+0x8d/0x9f0 [ 51.267902] ? complete+0x62/0x80 [ 51.271341] ucma_close+0x101/0x2d0 [ 51.274954] __fput+0x25a/0x780 [ 51.278219] ____fput+0x9/0x10 [ 51.281388] task_work_run+0x10e/0x190 [ 51.285259] do_exit+0x99c/0x2ce0 [ 51.288693] ? __kasan_check_read+0x11/0x20 [ 51.293018] ? mm_update_next_owner+0x710/0x710 [ 51.297673] ? get_signal+0x2c4/0x1d00 [ 51.301570] ? lock_downgrade+0x900/0x900 [ 51.305703] ? _raw_spin_unlock_irq+0x22/0x70 [ 51.310178] ? get_signal+0x2c4/0x1d00 [ 51.314055] do_group_exit+0xf4/0x2e0 [ 51.317843] get_signal+0x368/0x1d00 [ 51.321547] ? _raw_spin_unlock_irq+0x22/0x70 [ 51.326091] ? finish_task_switch+0x12a/0x630 [ 51.330573] ? lockdep_hardirqs_on+0x42d/0x5d0 [ 51.335148] do_signal+0x87/0x16c0 [ 51.338698] ? finish_task_switch+0x12a/0x630 [ 51.343172] ? finish_task_switch+0xf3/0x630 [ 51.347567] ? rcu_is_watching+0x31/0x80 [ 51.351623] ? setup_sigcontext+0x7d0/0x7d0 [ 51.355926] ? __x64_sys_futex+0x1cb/0x38e [ 51.360156] ? rcu_read_lock_any_held.part.8+0x50/0x50 [ 51.365412] ? __sched_text_start+0x8/0x8 [ 51.369542] ? exit_to_usermode_loop+0x3a/0x210 [ 51.374201] ? do_syscall_64+0x50b/0x600 [ 51.378241] ? lockdep_hardirqs_on+0x42d/0x5d0 [ 51.382803] ? exit_to_usermode_loop+0x3a/0x210 [ 51.387454] ? trace_hardirqs_on+0x28/0x180 [ 51.391758] exit_to_usermode_loop+0x114/0x210 [ 51.396343] do_syscall_64+0x50b/0x600 [ 51.400237] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.405406] RIP: 0033:0x4549c9 [ 51.408579] Code: e8 6c b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 51.427484] RSP: 002b:00007fd48206fce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 51.435194] RAX: fffffffffffffe00 RBX: 000000000072bf80 RCX: 00000000004549c9 [ 51.442448] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf80 [ 51.449698] RBP: 000000000072bf80 R08: 0000000000000000 R09: 000000000072bf58 [ 51.456946] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 51.464194] R13: 00007ffc1887b8af R14: 00007fd4820709c0 R15: 0000000000000001 [ 51.471480] [ 51.473091] Allocated by task 4213: [ 51.476715] save_stack+0x21/0x90 [ 51.480168] __kasan_kmalloc.constprop.7+0xc1/0xd0 [ 51.485087] kasan_kmalloc+0x9/0x10 [ 51.488693] kmem_cache_alloc_trace+0x15b/0x760 [ 51.493349] __rdma_create_id+0x5d/0x510 [ 51.497409] ucma_create_id+0x199/0x550 [ 51.501365] ucma_write+0x206/0x2e0 [ 51.504966] __vfs_write+0x61/0x110 [ 51.508569] vfs_write+0x191/0x4c0 [ 51.512206] ksys_write+0x197/0x220 [ 51.515815] __x64_sys_write+0x6e/0xb0 [ 51.519710] do_syscall_64+0xd0/0x600 [ 51.523507] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.528872] [ 51.530499] Freed by task 4213: [ 51.533793] save_stack+0x21/0x90 [ 51.537223] __kasan_slab_free+0x11a/0x170 [ 51.541447] kasan_slab_free+0xe/0x10 [ 51.545222] kfree+0xfa/0x290 [ 51.548319] rdma_destroy_id+0x60e/0x9f0 [ 51.552358] ucma_close+0x101/0x2d0 [ 51.555978] __fput+0x25a/0x780 [ 51.559235] ____fput+0x9/0x10 [ 51.562417] task_work_run+0x10e/0x190 [ 51.566282] do_exit+0x99c/0x2ce0 [ 51.569711] do_group_exit+0xf4/0x2e0 [ 51.573504] get_signal+0x368/0x1d00 [ 51.577214] do_signal+0x87/0x16c0 [ 51.580733] exit_to_usermode_loop+0x114/0x210 [ 51.585295] do_syscall_64+0x50b/0x600 [ 51.589161] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.594325] [ 51.595931] The buggy address belongs to the object at ffff8881d00d6000 [ 51.595931] which belongs to the cache kmalloc-2k of size 2048 [ 51.608582] The buggy address is located 488 bytes inside of [ 51.608582] 2048-byte region [ffff8881d00d6000, ffff8881d00d6800) [ 51.620536] The buggy address belongs to the page: [ 51.625445] page:ffffea0007403580 refcount:1 mapcount:0 mapping:ffff8881da000e00 index:0x0 [ 51.633839] raw: 02fffc0000000200 ffffea0007403508 ffffea00074035c8 ffff8881da000e00 [ 51.641707] raw: 0000000000000000 ffff8881d00d6000 0000000100000001 0000000000000000 [ 51.649653] page dumped because: kasan: bad access detected [ 51.655356] [ 51.656977] Memory state around the buggy address: [ 51.661887] ffff8881d00d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.669236] ffff8881d00d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.676659] >ffff8881d00d6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.683996] ^ [ 51.690737] ffff8881d00d6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.698086] ffff8881d00d6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.705435] ================================================================== [ 51.712890] Disabling lock debugging due to kernel taint [ 51.718535] Kernel panic - not syncing: panic_on_warn set ... [ 51.724412] CPU: 1 PID: 4237 Comm: syz-executor2 Tainted: G B 5.5.0-rc1-syzkaller #0 [ 51.733573] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.742904] Call Trace: [ 51.745484] dump_stack+0x12f/0x187 [ 51.749210] ? __list_del_entry_valid+0xb0/0xf3 [ 51.753876] panic+0x22a/0x4f5 [ 51.757060] ? add_taint.cold.7+0x11/0x11 [ 51.761465] ? do_raw_spin_unlock+0x54/0x260 [ 51.765936] ? do_raw_spin_unlock+0x54/0x260 [ 51.770321] ? __list_del_entry_valid+0xe7/0xf3 [ 51.774963] ? __list_del_entry_valid+0xe7/0xf3 [ 51.779630] end_report+0x47/0x4f [ 51.783071] __kasan_report.cold.11+0xe/0x39 [ 51.787542] ? __list_del_entry_valid+0xe7/0xf3 [ 51.792198] kasan_report+0x12/0x20 [ 51.795804] __asan_report_load8_noabort+0x14/0x20 [ 51.800708] __list_del_entry_valid+0xe7/0xf3 [ 51.805201] cma_cancel_operation+0x2f7/0x9c0 [ 51.809687] rdma_destroy_id+0x8d/0x9f0 [ 51.813639] ? complete+0x62/0x80 [ 51.817073] ucma_close+0x101/0x2d0 [ 51.820688] __fput+0x25a/0x780 [ 51.823956] ____fput+0x9/0x10 [ 51.827126] task_work_run+0x10e/0x190 [ 51.830995] do_exit+0x99c/0x2ce0 [ 51.834425] ? __kasan_check_read+0x11/0x20 [ 51.838726] ? mm_update_next_owner+0x710/0x710 [ 51.843372] ? get_signal+0x2c4/0x1d00 [ 51.847425] ? lock_downgrade+0x900/0x900 [ 51.851560] ? _raw_spin_unlock_irq+0x22/0x70 [ 51.856029] ? get_signal+0x2c4/0x1d00 [ 51.859896] do_group_exit+0xf4/0x2e0 [ 51.863674] get_signal+0x368/0x1d00 [ 51.867364] ? _raw_spin_unlock_irq+0x22/0x70 [ 51.871850] ? finish_task_switch+0x12a/0x630 [ 51.876328] ? lockdep_hardirqs_on+0x42d/0x5d0 [ 51.881323] do_signal+0x87/0x16c0 [ 51.884842] ? finish_task_switch+0x12a/0x630 [ 51.889318] ? finish_task_switch+0xf3/0x630 [ 51.893703] ? rcu_is_watching+0x31/0x80 [ 51.897801] ? setup_sigcontext+0x7d0/0x7d0 [ 51.902125] ? __x64_sys_futex+0x1cb/0x38e [ 51.906374] ? rcu_read_lock_any_held.part.8+0x50/0x50 [ 51.911643] ? __sched_text_start+0x8/0x8 [ 51.915778] ? exit_to_usermode_loop+0x3a/0x210 [ 51.920426] ? do_syscall_64+0x50b/0x600 [ 51.924477] ? lockdep_hardirqs_on+0x42d/0x5d0 [ 51.929040] ? exit_to_usermode_loop+0x3a/0x210 [ 51.933684] ? trace_hardirqs_on+0x28/0x180 [ 51.938023] exit_to_usermode_loop+0x114/0x210 [ 51.943478] do_syscall_64+0x50b/0x600 [ 51.947352] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.952519] RIP: 0033:0x4549c9 [ 51.955713] Code: e8 6c b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 51.974720] RSP: 002b:00007fd48206fce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 51.982404] RAX: fffffffffffffe00 RBX: 000000000072bf80 RCX: 00000000004549c9 [ 51.989661] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf80 [ 51.996910] RBP: 000000000072bf80 R08: 0000000000000000 R09: 000000000072bf58 [ 52.004160] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 52.011423] R13: 00007ffc1887b8af R14: 00007fd4820709c0 R15: 0000000000000001 [ 52.019476] Kernel Offset: disabled [ 52.023127] Rebooting in 86400 seconds..