INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] 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 'ci-upstream-kasan-gce-386-1,10.128.15.209' (ECDSA) to the list of known hosts. 2017/10/17 06:04:11 parsed 1 programs 2017/10/17 06:04:11 executed programs: 0 syzkaller login: [ 33.604694] ================================================================== [ 33.605847] BUG: KASAN: use-after-free in snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 33.606911] Read of size 8 at addr ffff8801d0dd9d00 by task syz-executor0/3342 [ 33.607872] [ 33.608104] CPU: 1 PID: 3342 Comm: syz-executor0 Not tainted 4.14.0-rc5+ #44 [ 33.609062] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.610278] Call Trace: [ 33.610637] dump_stack+0x194/0x257 [ 33.611145] ? arch_local_irq_restore+0x53/0x53 [ 33.611770] ? show_regs_print_info+0x65/0x65 [ 33.612372] ? lock_downgrade+0x990/0x990 [ 33.612947] ? snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 33.613769] print_address_description+0x73/0x250 [ 33.614412] ? snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 33.615181] kasan_report+0x25b/0x340 [ 33.615699] __asan_report_load8_noabort+0x14/0x20 [ 33.616354] snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 33.617110] ? snd_timer_user_tinterrupt+0x960/0x960 [ 33.617797] ? check_same_owner+0x320/0x320 [ 33.618375] ? check_stack_object+0x140/0x140 [ 33.619003] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.619642] ? __might_sleep+0x95/0x190 [ 33.620197] snd_timer_user_ioctl_compat+0x464/0x821 [ 33.620875] ? snd_timer_user_ioctl+0x32e0/0x32e0 [ 33.621523] ? selinux_capable+0x40/0x40 [ 33.622072] ? kmem_cache_free+0x249/0x280 [ 33.622642] ? putname+0xf3/0x130 [ 33.623120] ? security_file_ioctl+0x89/0xb0 [ 33.623717] compat_SyS_ioctl+0x1d7/0x3290 [ 33.624288] ? compat_SyS_get_robust_list+0x300/0x300 [ 33.625754] ? snd_timer_user_ioctl+0x32e0/0x32e0 [ 33.630564] ? do_ioctl+0x60/0x60 [ 33.633989] ? do_fast_syscall_32+0x158/0xf05 [ 33.638457] ? do_ioctl+0x60/0x60 [ 33.641877] do_fast_syscall_32+0x3f2/0xf05 [ 33.646172] ? do_int80_syscall_32+0x940/0x940 [ 33.650730] ? syscall_return_slowpath+0x2b3/0x510 [ 33.655622] ? finish_task_switch+0x1aa/0x740 [ 33.660086] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 33.665074] ? sysret32_from_system_call+0x5/0x3b [ 33.669885] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.674715] entry_SYSENTER_compat+0x51/0x60 [ 33.679091] RIP: 0023:0xf7fd4c79 [ 33.682422] RSP: 002b:00000000f7faf05c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 [ 33.690093] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080e05411 [ 33.697328] RDX: 0000000020db8fe5 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.704565] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 33.711801] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 33.719047] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 33.726297] [ 33.727892] Allocated by task 3341: [ 33.731485] save_stack_trace+0x16/0x20 [ 33.735460] save_stack+0x43/0xd0 [ 33.738883] kasan_kmalloc+0xad/0xe0 [ 33.742561] kmem_cache_alloc_trace+0x136/0x750 [ 33.747195] snd_timer_instance_new+0xda/0x610 [ 33.751741] snd_timer_open+0x180/0x1790 [ 33.755768] snd_timer_user_ioctl+0x96f/0x32e0 [ 33.760314] snd_timer_user_ioctl_compat+0x615/0x821 [ 33.765380] compat_SyS_ioctl+0x1d7/0x3290 [ 33.769582] do_fast_syscall_32+0x3f2/0xf05 [ 33.773872] entry_SYSENTER_compat+0x51/0x60 [ 33.778240] [ 33.779832] Freed by task 3341: [ 33.783077] save_stack_trace+0x16/0x20 [ 33.787018] save_stack+0x43/0xd0 [ 33.790434] kasan_slab_free+0x71/0xc0 [ 33.794287] kfree+0xca/0x250 [ 33.797356] snd_timer_close+0xa02/0xf20 [ 33.801380] snd_timer_user_ioctl+0x80d/0x32e0 [ 33.805926] snd_timer_user_ioctl_compat+0x615/0x821 [ 33.810995] compat_SyS_ioctl+0x1d7/0x3290 [ 33.815194] do_fast_syscall_32+0x3f2/0xf05 [ 33.819480] entry_SYSENTER_compat+0x51/0x60 [ 33.823849] [ 33.825445] The buggy address belongs to the object at ffff8801d0dd9d00 [ 33.825445] which belongs to the cache kmalloc-256 of size 256 [ 33.838066] The buggy address is located 0 bytes inside of [ 33.838066] 256-byte region [ffff8801d0dd9d00, ffff8801d0dd9e00) [ 33.849732] The buggy address belongs to the page: [ 33.854627] page:ffffea0007437640 count:1 mapcount:0 mapping:ffff8801d0dd9080 index:0x0 [ 33.862735] flags: 0x200000000000100(slab) [ 33.866940] raw: 0200000000000100 ffff8801d0dd9080 0000000000000000 000000010000000c [ 33.874787] raw: ffffea000741b4a0 ffffea0007400820 ffff8801dac007c0 0000000000000000 [ 33.882630] page dumped because: kasan: bad access detected [ 33.888303] [ 33.889896] Memory state around the buggy address: [ 33.894790] ffff8801d0dd9c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.902113] ffff8801d0dd9c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 33.909434] >ffff8801d0dd9d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.916755] ^ [ 33.920085] ffff8801d0dd9d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.927407] ffff8801d0dd9e00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 [ 33.934728] ================================================================== [ 33.942049] Disabling lock debugging due to kernel taint [ 33.947531] Kernel panic - not syncing: panic_on_warn set ... [ 33.947531] [ 33.954864] CPU: 1 PID: 3342 Comm: syz-executor0 Tainted: G B 4.14.0-rc5+ #44 [ 33.963228] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.972548] Call Trace: [ 33.975108] dump_stack+0x194/0x257 [ 33.978705] ? arch_local_irq_restore+0x53/0x53 [ 33.983340] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.988075] ? snd_timer_user_info_compat.isra.6+0x390/0x480 [ 33.993842] panic+0x1e4/0x417 [ 33.996999] ? __warn+0x1d9/0x1d9 [ 34.000423] ? snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 34.006184] kasan_end_report+0x50/0x50 [ 34.010121] kasan_report+0x144/0x340 [ 34.013886] __asan_report_load8_noabort+0x14/0x20 [ 34.018779] snd_timer_user_info_compat.isra.6+0x46c/0x480 [ 34.024368] ? snd_timer_user_tinterrupt+0x960/0x960 [ 34.029439] ? check_same_owner+0x320/0x320 [ 34.033727] ? check_stack_object+0x140/0x140 [ 34.038186] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 34.042908] ? __might_sleep+0x95/0x190 [ 34.046854] snd_timer_user_ioctl_compat+0x464/0x821 [ 34.051924] ? snd_timer_user_ioctl+0x32e0/0x32e0 [ 34.056736] ? selinux_capable+0x40/0x40 [ 34.060764] ? kmem_cache_free+0x249/0x280 [ 34.064964] ? putname+0xf3/0x130 [ 34.068386] ? security_file_ioctl+0x89/0xb0 [ 34.072761] compat_SyS_ioctl+0x1d7/0x3290 [ 34.076961] ? compat_SyS_get_robust_list+0x300/0x300 [ 34.082122] ? snd_timer_user_ioctl+0x32e0/0x32e0 [ 34.086938] ? do_ioctl+0x60/0x60 [ 34.090356] ? do_fast_syscall_32+0x158/0xf05 [ 34.094816] ? do_ioctl+0x60/0x60 [ 34.098234] do_fast_syscall_32+0x3f2/0xf05 [ 34.102524] ? do_int80_syscall_32+0x940/0x940 [ 34.107074] ? syscall_return_slowpath+0x2b3/0x510 [ 34.111966] ? finish_task_switch+0x1aa/0x740 [ 34.116428] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 34.121412] ? sysret32_from_system_call+0x5/0x3b [ 34.126221] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.131030] entry_SYSENTER_compat+0x51/0x60 [ 34.135404] RIP: 0023:0xf7fd4c79 [ 34.138731] RSP: 002b:00000000f7faf05c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 [ 34.146404] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080e05411 [ 34.153644] RDX: 0000000020db8fe5 RSI: 0000000000000000 RDI: 0000000000000000 [ 34.160883] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 34.168122] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 34.175357] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 34.182644] Dumping ftrace buffer: [ 34.186156] (ftrace buffer empty) [ 34.189835] Kernel Offset: disabled [ 34.193430] Rebooting in 86400 seconds..