Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.121' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 26.712190] ================================================================== [ 26.719632] BUG: KASAN: slab-out-of-bounds in find_first_zero_bit+0x84/0x90 [ 26.726708] Read of size 8 at addr ffff8880a6f68cc0 by task syz-executor359/7967 [ 26.734210] [ 26.735812] CPU: 1 PID: 7967 Comm: syz-executor359 Not tainted 4.14.278-syzkaller #0 [ 26.743666] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.752993] Call Trace: [ 26.755556] dump_stack+0x1b2/0x281 [ 26.759159] print_address_description.cold+0x54/0x1d3 [ 26.764411] kasan_report_error.cold+0x8a/0x191 [ 26.769055] ? find_first_zero_bit+0x84/0x90 [ 26.773440] __asan_report_load8_noabort+0x68/0x70 [ 26.778345] ? do_raw_spin_unlock+0x70/0x220 [ 26.782724] ? find_first_zero_bit+0x84/0x90 [ 26.787104] find_first_zero_bit+0x84/0x90 [ 26.791310] bfs_create+0xfb/0x620 [ 26.794843] ? bfs_find_entry.part.0.constprop.0+0x370/0x370 [ 26.800613] ? bfs_link+0x220/0x220 [ 26.804214] lookup_open+0x77a/0x1750 [ 26.807994] ? vfs_mkdir+0x6e0/0x6e0 [ 26.811685] path_openat+0xe08/0x2970 [ 26.815464] ? path_lookupat+0x780/0x780 [ 26.819499] ? trace_hardirqs_on+0x10/0x10 [ 26.823707] ? __lock_acquire+0x5fc/0x3f20 [ 26.827917] do_filp_open+0x179/0x3c0 [ 26.831692] ? may_open_dev+0xe0/0xe0 [ 26.835469] ? lock_downgrade+0x740/0x740 [ 26.839601] ? do_raw_spin_unlock+0x164/0x220 [ 26.844071] ? _raw_spin_unlock+0x29/0x40 [ 26.848197] ? __alloc_fd+0x1be/0x490 [ 26.851972] do_sys_open+0x296/0x410 [ 26.855662] ? filp_open+0x60/0x60 [ 26.859174] ? __close_fd+0x159/0x230 [ 26.862957] ? do_syscall_64+0x4c/0x640 [ 26.866904] ? compat_SyS_openat+0x30/0x30 [ 26.871112] do_syscall_64+0x1d5/0x640 [ 26.874976] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 26.880137] RIP: 0033:0x7f8bc60cbe29 [ 26.883820] RSP: 002b:00007fff57ed6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [ 26.891500] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8bc60cbe29 [ 26.898744] RDX: 00007f8bc608a3f3 RSI: 0000000000000068 RDI: 0000000020000f40 [ 26.905991] RBP: 00007f8bc608b6c0 R08: 0000000000000000 R09: 0000000000000000 [ 26.913233] R10: 00007fff57ed6030 R11: 0000000000000246 R12: 00007f8bc608b750 [ 26.920483] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 26.927731] [ 26.929333] Allocated by task 7967: [ 26.932940] kasan_kmalloc+0xeb/0x160 [ 26.936714] __kmalloc+0x15a/0x400 [ 26.940226] bfs_fill_super+0x3d5/0xd80 [ 26.944171] mount_bdev+0x2b3/0x360 [ 26.947773] mount_fs+0x92/0x2a0 [ 26.951114] vfs_kern_mount.part.0+0x5b/0x470 [ 26.955583] do_mount+0xe65/0x2a10 [ 26.959097] SyS_mount+0xa8/0x120 [ 26.962521] do_syscall_64+0x1d5/0x640 [ 26.966382] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 26.971538] [ 26.973137] Freed by task 6053: [ 26.976391] kasan_slab_free+0xc3/0x1a0 [ 26.980336] kfree+0xc9/0x250 [ 26.983413] aa_free_task_context+0xda/0x130 [ 26.987794] apparmor_cred_free+0x34/0x70 [ 26.991918] security_cred_free+0x71/0xb0 [ 26.996036] put_cred_rcu+0xe3/0x300 [ 26.999720] __put_cred+0x1a1/0x210 [ 27.003318] SyS_faccessat+0x52a/0x680 [ 27.007176] do_syscall_64+0x1d5/0x640 [ 27.011036] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.016195] [ 27.017795] The buggy address belongs to the object at ffff8880a6f68cc0 [ 27.017795] which belongs to the cache kmalloc-32 of size 32 [ 27.030247] The buggy address is located 0 bytes inside of [ 27.030247] 32-byte region [ffff8880a6f68cc0, ffff8880a6f68ce0) [ 27.041827] The buggy address belongs to the page: [ 27.046742] page:ffffea00029bda00 count:1 mapcount:0 mapping:ffff8880a6f68000 index:0xffff8880a6f68fc1 [ 27.056162] flags: 0xfff00000000100(slab) [ 27.060288] raw: 00fff00000000100 ffff8880a6f68000 ffff8880a6f68fc1 000000010000002a [ 27.068145] raw: ffffea0002c031a0 ffffea0002bde560 ffff88813fe741c0 0000000000000000 [ 27.076005] page dumped because: kasan: bad access detected [ 27.081688] [ 27.083290] Memory state around the buggy address: [ 27.088191] ffff8880a6f68b80: 00 03 fc fc fc fc fc fc 00 00 00 00 fc fc fc fc [ 27.095519] ffff8880a6f68c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 27.102849] >ffff8880a6f68c80: 00 03 fc fc fc fc fc fc 07 fc fc fc fc fc fc fc [ 27.110177] ^ [ 27.115597] ffff8880a6f68d00: fb fb fb fb fc fc fc fc 05 fc fc fc fc fc fc fc [ 27.122943] ffff8880a6f68d80: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc [ 27.130273] ================================================================== [ 27.137601] Disabling lock debugging due to kernel taint [ 27.153136] Kernel panic - not syncing: panic_on_warn set ... [ 27.153136] [ 27.160502] CPU: 0 PID: 7967 Comm: syz-executor359 Tainted: G B 4.14.278-syzkaller #0 [ 27.169576] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.178902] Call Trace: [ 27.181465] dump_stack+0x1b2/0x281 [ 27.185066] panic+0x1f9/0x42d [ 27.188229] ? add_taint.cold+0x16/0x16 [ 27.192181] ? ___preempt_schedule+0x16/0x18 [ 27.196569] kasan_end_report+0x43/0x49 [ 27.200512] kasan_report_error.cold+0xa7/0x191 [ 27.205238] ? find_first_zero_bit+0x84/0x90 [ 27.209617] __asan_report_load8_noabort+0x68/0x70 [ 27.214519] ? do_raw_spin_unlock+0x70/0x220 [ 27.218900] ? find_first_zero_bit+0x84/0x90 [ 27.223286] find_first_zero_bit+0x84/0x90 [ 27.227582] bfs_create+0xfb/0x620 [ 27.231114] ? bfs_find_entry.part.0.constprop.0+0x370/0x370 [ 27.236938] ? bfs_link+0x220/0x220 [ 27.240542] lookup_open+0x77a/0x1750 [ 27.244320] ? vfs_mkdir+0x6e0/0x6e0 [ 27.248007] path_openat+0xe08/0x2970 [ 27.251781] ? path_lookupat+0x780/0x780 [ 27.255818] ? trace_hardirqs_on+0x10/0x10 [ 27.260027] ? __lock_acquire+0x5fc/0x3f20 [ 27.264236] do_filp_open+0x179/0x3c0 [ 27.268007] ? may_open_dev+0xe0/0xe0 [ 27.271785] ? lock_downgrade+0x740/0x740 [ 27.275909] ? do_raw_spin_unlock+0x164/0x220 [ 27.280377] ? _raw_spin_unlock+0x29/0x40 [ 27.284496] ? __alloc_fd+0x1be/0x490 [ 27.288273] do_sys_open+0x296/0x410 [ 27.291958] ? filp_open+0x60/0x60 [ 27.295467] ? __close_fd+0x159/0x230 [ 27.299239] ? do_syscall_64+0x4c/0x640 [ 27.303205] ? compat_SyS_openat+0x30/0x30 [ 27.307415] do_syscall_64+0x1d5/0x640 [ 27.311276] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.316439] RIP: 0033:0x7f8bc60cbe29 [ 27.320129] RSP: 002b:00007fff57ed6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [ 27.327812] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8bc60cbe29 [ 27.335074] RDX: 00007f8bc608a3f3 RSI: 0000000000000068 RDI: 0000000020000f40 [ 27.342335] RBP: 00007f8bc608b6c0 R08: 0000000000000000 R09: 0000000000000000 [ 27.349579] R10: 00007fff57ed6030 R11: 0000000000000246 R12: 00007f8bc608b750 [ 27.356822] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 27.364242] Kernel Offset: disabled [ 27.367846] Rebooting in 86400 seconds..