[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.349372] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.729561] random: sshd: uninitialized urandom read (32 bytes read) [ 24.006615] random: sshd: uninitialized urandom read (32 bytes read) [ 24.807212] random: sshd: uninitialized urandom read (32 bytes read) [ 39.487245] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.36' (ECDSA) to the list of known hosts. [ 44.938699] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 45.030356] ================================================================== [ 45.037793] BUG: KASAN: slab-out-of-bounds in sha1_finup+0x44e/0x4b0 [ 45.044265] Write of size 4 at addr ffff8801d71f3958 by task syz-executor474/4581 [ 45.051856] [ 45.053467] CPU: 0 PID: 4581 Comm: syz-executor474 Not tainted 4.17.0+ #89 [ 45.060463] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.069791] Call Trace: [ 45.072368] dump_stack+0x1b9/0x294 [ 45.075976] ? dump_stack_print_info.cold.2+0x52/0x52 [ 45.081178] ? printk+0x9e/0xba [ 45.084436] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 45.089175] ? kasan_check_write+0x14/0x20 [ 45.093400] print_address_description+0x6c/0x20b [ 45.098226] ? sha1_finup+0x44e/0x4b0 [ 45.102005] kasan_report.cold.7+0x242/0x2fe [ 45.106409] __asan_report_store4_noabort+0x17/0x20 [ 45.111424] sha1_finup+0x44e/0x4b0 [ 45.115063] ? sha1_base_init+0x150/0x150 [ 45.119226] sha1_avx2_final+0x28/0x30 [ 45.123094] crypto_shash_final+0x104/0x260 [ 45.127404] ? sha1_avx2_finup+0x40/0x40 [ 45.131452] __keyctl_dh_compute+0x1184/0x1bc0 [ 45.136030] ? copy_overflow+0x30/0x30 [ 45.140090] ? find_held_lock+0x36/0x1c0 [ 45.144166] ? lock_downgrade+0x8e0/0x8e0 [ 45.148309] ? check_same_owner+0x320/0x320 [ 45.152791] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 45.158313] ? handle_mm_fault+0x55a/0xc70 [ 45.162539] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.168064] ? _copy_from_user+0xdf/0x150 [ 45.172202] keyctl_dh_compute+0xb9/0x100 [ 45.176341] ? __keyctl_dh_compute+0x1bc0/0x1bc0 [ 45.181086] ? kzfree+0x28/0x30 [ 45.184352] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 45.189534] __x64_sys_keyctl+0x12a/0x3b0 [ 45.193680] do_syscall_64+0x1b1/0x800 [ 45.197563] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 45.202392] ? syscall_return_slowpath+0x5c0/0x5c0 [ 45.207309] ? syscall_return_slowpath+0x30f/0x5c0 [ 45.212224] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.217753] ? retint_user+0x18/0x18 [ 45.221460] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.226296] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.231487] RIP: 0033:0x43ffa9 [ 45.234659] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00 [ 45.254068] RSP: 002b:00007fffd75787b8 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa [ 45.261776] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffa9 [ 45.269054] RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017 [ 45.276318] RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8 [ 45.283574] R10: 0000000000000005 R11: 0000000000000217 R12: 00000000004018d0 [ 45.290843] R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000 [ 45.298190] [ 45.299811] Allocated by task 4581: [ 45.303437] save_stack+0x43/0xd0 [ 45.306882] kasan_kmalloc+0xc4/0xe0 [ 45.310580] __kmalloc+0x14e/0x760 [ 45.314141] __keyctl_dh_compute+0xfe9/0x1bc0 [ 45.318624] keyctl_dh_compute+0xb9/0x100 [ 45.322766] __x64_sys_keyctl+0x12a/0x3b0 [ 45.326917] do_syscall_64+0x1b1/0x800 [ 45.330821] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.336004] [ 45.337628] Freed by task 2886: [ 45.340905] save_stack+0x43/0xd0 [ 45.344347] __kasan_slab_free+0x11a/0x170 [ 45.348573] kasan_slab_free+0xe/0x10 [ 45.352373] kfree+0xd9/0x260 [ 45.355474] single_release+0x8f/0xb0 [ 45.359262] __fput+0x353/0x890 [ 45.362529] ____fput+0x15/0x20 [ 45.365798] task_work_run+0x1e4/0x290 [ 45.369682] exit_to_usermode_loop+0x2bd/0x310 [ 45.374269] do_syscall_64+0x6ac/0x800 [ 45.378159] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.383329] [ 45.384941] The buggy address belongs to the object at ffff8801d71f3940 [ 45.384941] which belongs to the cache kmalloc-32 of size 32 [ 45.397411] The buggy address is located 24 bytes inside of [ 45.397411] 32-byte region [ffff8801d71f3940, ffff8801d71f3960) [ 45.409102] The buggy address belongs to the page: [ 45.414024] page:ffffea00075c7cc0 count:1 mapcount:0 mapping:ffff8801d71f3000 index:0xffff8801d71f3fc1 [ 45.423471] flags: 0x2fffc0000000100(slab) [ 45.427697] raw: 02fffc0000000100 ffff8801d71f3000 ffff8801d71f3fc1 000000010000003d [ 45.435567] raw: ffffea0007606f20 ffffea00075c7be0 ffff8801da8001c0 0000000000000000 [ 45.443440] page dumped because: kasan: bad access detected [ 45.449130] [ 45.450742] Memory state around the buggy address: [ 45.455666] ffff8801d71f3800: 00 00 00 00 fc fc fc fc 00 fc fc fc fc fc fc fc [ 45.463022] ffff8801d71f3880: 00 00 00 00 fc fc fc fc 00 fc fc fc fc fc fc fc [ 45.470364] >ffff8801d71f3900: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc [ 45.477710] ^ [ 45.483935] ffff8801d71f3980: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 45.491278] ffff8801d71f3a00: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc [ 45.498625] ================================================================== [ 45.505972] Disabling lock debugging due to kernel taint [ 45.511627] Kernel panic - not syncing: panic_on_warn set ... [ 45.511627] [ 45.519006] CPU: 0 PID: 4581 Comm: syz-executor474 Tainted: G B 4.17.0+ #89 [ 45.527395] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.536739] Call Trace: [ 45.539332] dump_stack+0x1b9/0x294 [ 45.542971] ? dump_stack_print_info.cold.2+0x52/0x52 [ 45.548172] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.552919] ? sha1_finup+0x3a0/0x4b0 [ 45.556706] panic+0x22f/0x4de [ 45.559890] ? add_taint.cold.5+0x16/0x16 [ 45.564021] ? do_raw_spin_unlock+0x9e/0x2e0 [ 45.568412] ? do_raw_spin_unlock+0x9e/0x2e0 [ 45.572801] ? sha1_finup+0x44e/0x4b0 [ 45.576587] kasan_end_report+0x47/0x4f [ 45.580549] kasan_report.cold.7+0x76/0x2fe [ 45.584855] __asan_report_store4_noabort+0x17/0x20 [ 45.589855] sha1_finup+0x44e/0x4b0 [ 45.593461] ? sha1_base_init+0x150/0x150 [ 45.597592] sha1_avx2_final+0x28/0x30 [ 45.601463] crypto_shash_final+0x104/0x260 [ 45.605771] ? sha1_avx2_finup+0x40/0x40 [ 45.609821] __keyctl_dh_compute+0x1184/0x1bc0 [ 45.614389] ? copy_overflow+0x30/0x30 [ 45.618259] ? find_held_lock+0x36/0x1c0 [ 45.622302] ? lock_downgrade+0x8e0/0x8e0 [ 45.626430] ? check_same_owner+0x320/0x320 [ 45.630742] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 45.636269] ? handle_mm_fault+0x55a/0xc70 [ 45.640491] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.646022] ? _copy_from_user+0xdf/0x150 [ 45.650152] keyctl_dh_compute+0xb9/0x100 [ 45.654283] ? __keyctl_dh_compute+0x1bc0/0x1bc0 [ 45.659024] ? kzfree+0x28/0x30 [ 45.662283] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 45.667469] __x64_sys_keyctl+0x12a/0x3b0 [ 45.671835] do_syscall_64+0x1b1/0x800 [ 45.675715] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 45.680546] ? syscall_return_slowpath+0x5c0/0x5c0 [ 45.685456] ? syscall_return_slowpath+0x30f/0x5c0 [ 45.690367] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.695889] ? retint_user+0x18/0x18 [ 45.699589] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.704414] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.709586] RIP: 0033:0x43ffa9 [ 45.712764] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00 [ 45.731975] RSP: 002b:00007fffd75787b8 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa [ 45.739676] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffa9 [ 45.747118] RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017 [ 45.754376] RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8 [ 45.761634] R10: 0000000000000005 R11: 0000000000000217 R12: 00000000004018d0 [ 45.768899] R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000 [ 45.776676] Dumping ftrace buffer: [ 45.780202] (ftrace buffer empty) [ 45.783895] Kernel Offset: disabled [ 45.787506] Rebooting in 86400 seconds..