[....] Starting enhanced syslogd: rsyslogd[ 13.080192] audit: type=1400 audit(1517507941.534:4): avc: denied { syslog } for pid=3804 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?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 '10.128.0.2' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 34.607835] ================================================================== [ 34.615236] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0x103/0x120 [ 34.622311] Read of size 8 at addr ffff8801d93dd140 by task syzkaller822738/3969 [ 34.629814] [ 34.631420] CPU: 0 PID: 3969 Comm: syzkaller822738 Not tainted 4.9.79-g71f1469 #25 [ 34.639095] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.648424] ffff8801d78779b0 ffffffff81d94829 ffffea000764f740 ffff8801d93dd140 [ 34.656406] 0000000000000000 ffff8801d93dd140 ffff8801d4c82338 ffff8801d78779e8 [ 34.664386] ffffffff8153e083 ffff8801d93dd140 0000000000000008 0000000000000000 [ 34.672354] Call Trace: [ 34.674910] [] dump_stack+0xc1/0x128 [ 34.680249] [] print_address_description+0x73/0x280 [ 34.686895] [] kasan_report+0x275/0x360 [ 34.692489] [] ? sg_remove_request+0x103/0x120 [ 34.698694] [] __asan_report_load8_noabort+0x14/0x20 [ 34.705417] [] sg_remove_request+0x103/0x120 [ 34.711444] [] sg_finish_rem_req+0x295/0x340 [ 34.717469] [] sg_read+0xa16/0x1440 [ 34.722718] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 34.729355] [] ? fsnotify+0xf30/0xf30 [ 34.734789] [] ? avc_policy_seqno+0x9/0x20 [ 34.740646] [] do_loop_readv_writev.part.17+0x141/0x1e0 [ 34.747628] [] ? security_file_permission+0x89/0x1e0 [ 34.754354] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 34.760988] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 34.767627] [] do_readv_writev+0x520/0x750 [ 34.773482] [] ? vfs_write+0x530/0x530 [ 34.778987] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.784931] [] ? __pmd_alloc+0x410/0x410 [ 34.790615] [] ? __do_page_fault+0x5ec/0xd40 [ 34.796647] [] vfs_readv+0x84/0xc0 [ 34.801826] [] do_readv+0xe6/0x250 [ 34.806994] [] ? vfs_readv+0xc0/0xc0 [ 34.812338] [] ? entry_SYSCALL_64_fastpath+0x5/0xe8 [ 34.818977] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 34.825790] [] SyS_readv+0x27/0x30 [ 34.830951] [] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 34.837499] [ 34.839097] Allocated by task 0: [ 34.842434] (stack is not available) [ 34.846113] [ 34.847708] Freed by task 0: [ 34.850784] (stack is not available) [ 34.854461] [ 34.856057] The buggy address belongs to the object at ffff8801d93dd100 [ 34.856057] which belongs to the cache fasync_cache of size 96 [ 34.868681] The buggy address is located 64 bytes inside of [ 34.868681] 96-byte region [ffff8801d93dd100, ffff8801d93dd160) [ 34.880359] The buggy address belongs to the page: [ 34.885261] page:ffffea000764f740 count:1 mapcount:0 mapping: (null) index:0x0 [ 34.893484] flags: 0x8000000000000080(slab) [ 34.897778] page dumped because: kasan: bad access detected [ 34.903512] [ 34.905108] Memory state around the buggy address: [ 34.910005] ffff8801d93dd000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 34.917332] ffff8801d93dd080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.924661] >ffff8801d93dd100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.931988] ^ [ 34.937403] ffff8801d93dd180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.944730] ffff8801d93dd200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.952054] ================================================================== [ 34.959570] Disabling lock debugging due to kernel taint [ 34.965203] Kernel panic - not syncing: panic_on_warn set ... [ 34.965203] [ 34.972541] CPU: 0 PID: 3969 Comm: syzkaller822738 Tainted: G B 4.9.79-g71f1469 #25 [ 34.981434] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.990760] ffff8801d7877908 ffffffff81d94829 ffffffff8419709f ffff8801d78779e0 [ 34.998742] 0000000000000000 ffff8801d93dd140 ffff8801d4c82338 ffff8801d78779d0 [ 35.006721] ffffffff8142f531 0000000041b58ab3 ffffffff8418ab10 ffffffff8142f375 [ 35.014699] Call Trace: [ 35.017257] [] dump_stack+0xc1/0x128 [ 35.022597] [] panic+0x1bc/0x3a8 [ 35.027594] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 35.035793] [] ? preempt_schedule+0x25/0x30 [ 35.041736] [] ? ___preempt_schedule+0x16/0x18 [ 35.047935] [] kasan_end_report+0x50/0x50 [ 35.053714] [] kasan_report+0x167/0x360 [ 35.059308] [] ? sg_remove_request+0x103/0x120 [ 35.065520] [] __asan_report_load8_noabort+0x14/0x20 [ 35.072244] [] sg_remove_request+0x103/0x120 [ 35.078272] [] sg_finish_rem_req+0x295/0x340 [ 35.084298] [] sg_read+0xa16/0x1440 [ 35.089544] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 35.096180] [] ? fsnotify+0xf30/0xf30 [ 35.101603] [] ? avc_policy_seqno+0x9/0x20 [ 35.107460] [] do_loop_readv_writev.part.17+0x141/0x1e0 [ 35.114444] [] ? security_file_permission+0x89/0x1e0 [ 35.121167] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 35.127800] [] ? sg_proc_seq_show_debug+0xd90/0xd90 [ 35.134439] [] do_readv_writev+0x520/0x750 [ 35.140304] [] ? vfs_write+0x530/0x530 [ 35.145814] [] ? _raw_spin_unlock+0x2c/0x50 [ 35.151755] [] ? __pmd_alloc+0x410/0x410 [ 35.157440] [] ? __do_page_fault+0x5ec/0xd40 [ 35.163466] [] vfs_readv+0x84/0xc0 [ 35.168648] [] do_readv+0xe6/0x250 [ 35.173808] [] ? vfs_readv+0xc0/0xc0 [ 35.179140] [] ? entry_SYSCALL_64_fastpath+0x5/0xe8 [ 35.185779] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 35.192598] [] SyS_readv+0x27/0x30 [ 35.197765] [] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 35.204727] Dumping ftrace buffer: [ 35.208413] (ftrace buffer empty) [ 35.212095] Kernel Offset: disabled [ 35.215694] Rebooting in 86400 seconds..