[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.220' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.238717] BFS-fs: bfs_fill_super(): loop0 is unclean, continuing [ 27.246502] ================================================================== [ 27.253952] BUG: KASAN: slab-out-of-bounds in find_first_zero_bit+0x84/0x90 [ 27.261048] Read of size 8 at addr ffff8880b07797c0 by task syz-executor795/7971 [ 27.268562] [ 27.270171] CPU: 1 PID: 7971 Comm: syz-executor795 Not tainted 4.14.296-syzkaller #0 [ 27.278032] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 [ 27.287365] Call Trace: [ 27.289940] dump_stack+0x1b2/0x281 [ 27.293570] print_address_description.cold+0x54/0x1d3 [ 27.298837] kasan_report_error.cold+0x8a/0x191 [ 27.303498] ? find_first_zero_bit+0x84/0x90 [ 27.307898] __asan_report_load8_noabort+0x68/0x70 [ 27.312823] ? do_raw_spin_unlock+0xc0/0x220 [ 27.317219] ? find_first_zero_bit+0x84/0x90 [ 27.321697] find_first_zero_bit+0x84/0x90 [ 27.325915] bfs_create+0xfb/0x620 [ 27.329438] ? security_inode_permission+0xb5/0xf0 [ 27.334351] vfs_create+0x3e3/0x620 [ 27.337954] SyS_mknodat+0x2f4/0x470 [ 27.341645] ? do_file_open_root+0x490/0x490 [ 27.346033] ? __close_fd+0x159/0x230 [ 27.349821] ? do_syscall_64+0x4c/0x640 [ 27.353777] ? SyS_mknodat+0x470/0x470 [ 27.357649] do_syscall_64+0x1d5/0x640 [ 27.361522] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.366685] RIP: 0033:0x7fab5e059d79 [ 27.370373] RSP: 002b:00007ffd73ab32e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 [ 27.378054] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fab5e059d79 [ 27.385302] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 [ 27.392545] RBP: 00007fab5e0195e0 R08: 00005555570062c0 R09: 0000000000000000 [ 27.399796] R10: 00007ffd73ab31b0 R11: 0000000000000246 R12: 00007fab5e019670 [ 27.407053] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 27.414316] [ 27.415926] Allocated by task 7971: [ 27.419532] kasan_kmalloc+0xeb/0x160 [ 27.423321] __kmalloc+0x15a/0x400 [ 27.426841] bfs_fill_super+0x3d5/0xd80 [ 27.430791] mount_bdev+0x2b3/0x360 [ 27.434396] mount_fs+0x92/0x2a0 [ 27.437736] vfs_kern_mount.part.0+0x5b/0x470 [ 27.442205] do_mount+0xe65/0x2a30 [ 27.445745] SyS_mount+0xa8/0x120 [ 27.449173] do_syscall_64+0x1d5/0x640 [ 27.453039] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.458458] [ 27.460061] Freed by task 1: [ 27.463054] kasan_slab_free+0xc3/0x1a0 [ 27.467003] kfree+0xc9/0x250 [ 27.470083] kfree_const+0x33/0x40 [ 27.473844] kernfs_put.part.0+0x131/0x490 [ 27.478054] __kernfs_remove+0x417/0x920 [ 27.482089] kernfs_remove_by_name_ns+0x55/0x90 [ 27.486732] cgroup_addrm_files+0x548/0x840 [ 27.491028] css_clear_dir+0xf8/0x190 [ 27.494809] kill_css+0xa3/0x2d0 [ 27.498244] cgroup_destroy_locked+0x271/0x5b0 [ 27.502802] cgroup_rmdir+0x34/0x280 [ 27.506490] kernfs_iop_rmdir+0x14e/0x1d0 [ 27.510626] vfs_rmdir.part.0+0x144/0x390 [ 27.514756] do_rmdir+0x334/0x3c0 [ 27.518196] do_syscall_64+0x1d5/0x640 [ 27.522063] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.527225] [ 27.528836] The buggy address belongs to the object at ffff8880b07797c0 [ 27.528836] which belongs to the cache kmalloc-32 of size 32 [ 27.541382] The buggy address is located 0 bytes inside of [ 27.541382] 32-byte region [ffff8880b07797c0, ffff8880b07797e0) [ 27.552968] The buggy address belongs to the page: [ 27.557874] page:ffffea0002c1de40 count:1 mapcount:0 mapping:ffff8880b0779000 index:0xffff8880b0779fc1 [ 27.567294] flags: 0xfff00000000100(slab) [ 27.571416] raw: 00fff00000000100 ffff8880b0779000 ffff8880b0779fc1 000000010000003f [ 27.579313] raw: ffffea0002c28760 ffffea0002c1aca0 ffff88813fe741c0 0000000000000000 [ 27.587255] page dumped because: kasan: bad access detected [ 27.592940] [ 27.594543] Memory state around the buggy address: [ 27.599448] ffff8880b0779680: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc [ 27.606787] ffff8880b0779700: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc [ 27.614118] >ffff8880b0779780: fb fb fb fb fc fc fc fc 07 fc fc fc fc fc fc fc [ 27.621448] ^ [ 27.626869] ffff8880b0779800: 00 03 fc fc fc fc fc fc fb fb fb fb fc fc fc fc [ 27.634207] ffff8880b0779880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 27.641538] ================================================================== [ 27.648873] Disabling lock debugging due to kernel taint [ 27.654802] Kernel panic - not syncing: panic_on_warn set ... [ 27.654802] [ 27.662244] CPU: 1 PID: 7971 Comm: syz-executor795 Tainted: G B 4.14.296-syzkaller #0 [ 27.671330] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 [ 27.680847] Call Trace: [ 27.683428] dump_stack+0x1b2/0x281 [ 27.687039] panic+0x1f9/0x42d [ 27.690205] ? add_taint.cold+0x16/0x16 [ 27.694165] ? ___preempt_schedule+0x16/0x18 [ 27.698633] kasan_end_report+0x43/0x49 [ 27.702580] kasan_report_error.cold+0xa7/0x191 [ 27.707222] ? find_first_zero_bit+0x84/0x90 [ 27.711626] __asan_report_load8_noabort+0x68/0x70 [ 27.716527] ? do_raw_spin_unlock+0xc0/0x220 [ 27.720921] ? find_first_zero_bit+0x84/0x90 [ 27.725302] find_first_zero_bit+0x84/0x90 [ 27.729511] bfs_create+0xfb/0x620 [ 27.733026] ? security_inode_permission+0xb5/0xf0 [ 27.737928] vfs_create+0x3e3/0x620 [ 27.741541] SyS_mknodat+0x2f4/0x470 [ 27.745229] ? do_file_open_root+0x490/0x490 [ 27.749611] ? __close_fd+0x159/0x230 [ 27.753385] ? do_syscall_64+0x4c/0x640 [ 27.757329] ? SyS_mknodat+0x470/0x470 [ 27.761193] do_syscall_64+0x1d5/0x640 [ 27.765058] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.770220] RIP: 0033:0x7fab5e059d79 [ 27.773905] RSP: 002b:00007ffd73ab32e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 [ 27.781589] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fab5e059d79 [ 27.788835] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 [ 27.796079] RBP: 00007fab5e0195e0 R08: 00005555570062c0 R09: 0000000000000000 [ 27.803324] R10: 00007ffd73ab31b0 R11: 0000000000000246 R12: 00007fab5e019670 [ 27.810566] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 27.817990] Kernel Offset: disabled [ 27.821593] Rebooting in 86400 seconds..