[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.072184] audit: type=1800 audit(1549126829.666:25): pid=7661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 38.108570] audit: type=1800 audit(1549126829.666:26): pid=7661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 38.138738] audit: type=1800 audit(1549126829.666:27): pid=7661 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.227' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 64.222780] ================================================================== [ 64.230269] BUG: KASAN: use-after-free in __list_add_valid+0x9a/0xa0 [ 64.236745] Read of size 8 at addr ffff88808fb0ede0 by task syz-executor242/7905 [ 64.244257] [ 64.245887] CPU: 0 PID: 7905 Comm: syz-executor242 Not tainted 5.0.0-rc4+ #57 [ 64.253138] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.262472] Call Trace: [ 64.265172] dump_stack+0x172/0x1f0 [ 64.268783] ? __list_add_valid+0x9a/0xa0 [ 64.272916] print_address_description.cold+0x7c/0x20d [ 64.278171] ? __list_add_valid+0x9a/0xa0 [ 64.282320] ? __list_add_valid+0x9a/0xa0 [ 64.286449] kasan_report.cold+0x1b/0x40 [ 64.290490] ? __list_add_valid+0x9a/0xa0 [ 64.294621] __asan_report_load8_noabort+0x14/0x20 [ 64.299543] __list_add_valid+0x9a/0xa0 [ 64.303508] rdma_listen+0x63b/0x8e0 [ 64.307209] ucma_listen+0x14d/0x1c0 [ 64.310915] ? ucma_notify+0x190/0x190 [ 64.314897] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 64.320433] ? _copy_from_user+0xdd/0x150 [ 64.324669] ucma_write+0x2da/0x3c0 [ 64.328281] ? ucma_notify+0x190/0x190 [ 64.332271] ? ucma_open+0x290/0x290 [ 64.335965] ? debug_check_no_obj_freed+0x200/0x464 [ 64.341082] ? kasan_check_read+0x11/0x20 [ 64.345216] __vfs_write+0x116/0x8e0 [ 64.348908] ? ucma_open+0x290/0x290 [ 64.352712] ? kernel_read+0x120/0x120 [ 64.356585] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 64.361499] ? common_file_perm+0x1d6/0x6f0 [ 64.365849] ? apparmor_file_permission+0x25/0x30 [ 64.370813] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 64.376455] ? security_file_permission+0x94/0x320 [ 64.381382] ? rw_verify_area+0x118/0x360 [ 64.385514] vfs_write+0x20c/0x580 [ 64.389037] ksys_write+0xea/0x1f0 [ 64.392564] ? __ia32_sys_read+0xb0/0xb0 [ 64.396681] ? do_fast_syscall_32+0xd1/0xc98 [ 64.401084] ? entry_SYSENTER_compat+0x70/0x7f [ 64.405646] ? do_fast_syscall_32+0xd1/0xc98 [ 64.410095] __ia32_sys_write+0x71/0xb0 [ 64.414063] do_fast_syscall_32+0x281/0xc98 [ 64.418377] entry_SYSENTER_compat+0x70/0x7f [ 64.422769] RIP: 0023:0xf7f9d869 [ 64.426131] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 64.445140] RSP: 002b:00000000fffa4cfc EFLAGS: 00000207 ORIG_RAX: 0000000000000004 [ 64.452843] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000240 [ 64.460151] RDX: 0000000000000010 RSI: 0000000000000004 RDI: 0000000000000003 [ 64.467568] RBP: 00000000200002c0 R08: 0000000000000000 R09: 0000000000000000 [ 64.474931] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 64.482348] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 64.489616] [ 64.491229] Allocated by task 7829: [ 64.494839] save_stack+0x45/0xd0 [ 64.498281] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 64.503194] kasan_kmalloc+0x9/0x10 [ 64.506886] kmem_cache_alloc_trace+0x151/0x760 [ 64.511655] __rdma_create_id+0x5f/0x4e0 [ 64.515728] ucma_create_id+0x1de/0x640 [ 64.519695] ucma_write+0x2da/0x3c0 [ 64.523315] __vfs_write+0x116/0x8e0 [ 64.527065] vfs_write+0x20c/0x580 [ 64.530672] ksys_write+0xea/0x1f0 [ 64.534199] __ia32_sys_write+0x71/0xb0 [ 64.538154] do_fast_syscall_32+0x281/0xc98 [ 64.542457] entry_SYSENTER_compat+0x70/0x7f [ 64.546846] [ 64.548460] Freed by task 7829: [ 64.551720] save_stack+0x45/0xd0 [ 64.555171] __kasan_slab_free+0x102/0x150 [ 64.559387] kasan_slab_free+0xe/0x10 [ 64.563198] kfree+0xcf/0x230 [ 64.566487] rdma_destroy_id+0x723/0xab0 [ 64.570695] ucma_close+0x115/0x320 [ 64.574308] __fput+0x2df/0x8d0 [ 64.577713] ____fput+0x16/0x20 [ 64.580975] task_work_run+0x14a/0x1c0 [ 64.584844] exit_to_usermode_loop+0x273/0x2c0 [ 64.589423] do_fast_syscall_32+0xa9d/0xc98 [ 64.593726] entry_SYSENTER_compat+0x70/0x7f [ 64.598232] [ 64.599875] The buggy address belongs to the object at ffff88808fb0ec00 [ 64.599875] which belongs to the cache kmalloc-2k of size 2048 [ 64.612519] The buggy address is located 480 bytes inside of [ 64.612519] 2048-byte region [ffff88808fb0ec00, ffff88808fb0f400) [ 64.624559] The buggy address belongs to the page: [ 64.629581] page:ffffea00023ec380 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0 [ 64.639532] flags: 0x1fffc0000010200(slab|head) [ 64.644189] raw: 01fffc0000010200 ffffea00023b5288 ffffea00023dfe08 ffff88812c3f0c40 [ 64.652054] raw: 0000000000000000 ffff88808fb0e380 0000000100000003 0000000000000000 [ 64.659912] page dumped because: kasan: bad access detected [ 64.665676] [ 64.667286] Memory state around the buggy address: [ 64.672198] ffff88808fb0ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.679544] ffff88808fb0ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.686890] >ffff88808fb0ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.694392] ^ [ 64.700882] ffff88808fb0ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.708345] ffff88808fb0ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.715703] ================================================================== [ 64.723307] Disabling lock debugging due to kernel taint [ 64.729116] Kernel panic - not syncing: panic_on_warn set ... [ 64.735036] CPU: 0 PID: 7905 Comm: syz-executor242 Tainted: G B 5.0.0-rc4+ #57 [ 64.743789] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.753140] Call Trace: [ 64.755710] dump_stack+0x172/0x1f0 [ 64.759323] panic+0x2cb/0x65c [ 64.762523] ? __warn_printk+0xf3/0xf3 [ 64.766411] ? __list_add_valid+0x9a/0xa0 [ 64.770590] ? preempt_schedule+0x4b/0x60 [ 64.774727] ? ___preempt_schedule+0x16/0x18 [ 64.779126] ? trace_hardirqs_on+0x5e/0x230 [ 64.783432] ? __list_add_valid+0x9a/0xa0 [ 64.787734] end_report+0x47/0x4f [ 64.791177] ? __list_add_valid+0x9a/0xa0 [ 64.795360] kasan_report.cold+0xe/0x40 [ 64.799345] ? __list_add_valid+0x9a/0xa0 [ 64.803490] __asan_report_load8_noabort+0x14/0x20 [ 64.808415] __list_add_valid+0x9a/0xa0 [ 64.812393] rdma_listen+0x63b/0x8e0 [ 64.816091] ucma_listen+0x14d/0x1c0 [ 64.819797] ? ucma_notify+0x190/0x190 [ 64.823677] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 64.829194] ? _copy_from_user+0xdd/0x150 [ 64.833321] ucma_write+0x2da/0x3c0 [ 64.836944] ? ucma_notify+0x190/0x190 [ 64.840814] ? ucma_open+0x290/0x290 [ 64.844514] ? debug_check_no_obj_freed+0x200/0x464 [ 64.849521] ? kasan_check_read+0x11/0x20 [ 64.853669] __vfs_write+0x116/0x8e0 [ 64.857408] ? ucma_open+0x290/0x290 [ 64.861225] ? kernel_read+0x120/0x120 [ 64.865200] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 64.870116] ? common_file_perm+0x1d6/0x6f0 [ 64.874425] ? apparmor_file_permission+0x25/0x30 [ 64.879253] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 64.884799] ? security_file_permission+0x94/0x320 [ 64.889721] ? rw_verify_area+0x118/0x360 [ 64.893852] vfs_write+0x20c/0x580 [ 64.897382] ksys_write+0xea/0x1f0 [ 64.900903] ? __ia32_sys_read+0xb0/0xb0 [ 64.904965] ? do_fast_syscall_32+0xd1/0xc98 [ 64.909395] ? entry_SYSENTER_compat+0x70/0x7f [ 64.913956] ? do_fast_syscall_32+0xd1/0xc98 [ 64.918377] __ia32_sys_write+0x71/0xb0 [ 64.922337] do_fast_syscall_32+0x281/0xc98 [ 64.926664] entry_SYSENTER_compat+0x70/0x7f [ 64.931064] RIP: 0023:0xf7f9d869 [ 64.934417] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 64.953301] RSP: 002b:00000000fffa4cfc EFLAGS: 00000207 ORIG_RAX: 0000000000000004 [ 64.961000] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000240 [ 64.968265] RDX: 0000000000000010 RSI: 0000000000000004 RDI: 0000000000000003 [ 64.975626] RBP: 00000000200002c0 R08: 0000000000000000 R09: 0000000000000000 [ 64.982882] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 64.990132] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 64.998435] Kernel Offset: disabled [ 65.002053] Rebooting in 86400 seconds..