INIT: Entering runlevel: 2 [[36minfo[39;49m] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.20' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 44.207777] F2FS-fs (loop4): Magic Mismatch, valid(0xf2f52010) - read(0x0) [ 44.217458] F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) [ 44.217461] F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock [ 44.222382] F2FS-fs (loop6): Magic Mismatch, valid(0xf2f52010) - read(0x0) [ 44.222385] F2FS-fs (loop6): Can't find valid F2FS filesystem in 1th superblock [ 44.222630] F2FS-fs (loop6): invalid crc value [ 44.223433] F2FS-fs (loop7): Magic Mismatch, valid(0xf2f52010) - read(0x0) [ 44.223436] F2FS-fs (loop7): Can't find valid F2FS filesystem in 1th superblock [ 44.223684] F2FS-fs (loop7): invalid crc value [ 44.224990] F2FS-fs (loop0): invalid crc value executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 48.191359] ================================================================== [ 48.198748] BUG: KASAN: use-after-free in __kernfs_remove+0x742/0x830 [ 48.205300] Read of size 2 at addr ffff8801d42908f8 by task syzkaller241258/4394 [ 48.212806] [ 48.214415] CPU: 0 PID: 4394 Comm: syzkaller241258 Not tainted 4.9.95-g13cc540 #2 [ 48.222008] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.231334] ffff8801cf2e7628 ffffffff81eb0ba9 ffffea000750a400 ffff8801d42908f8 [ 48.239302] 0000000000000000 ffff8801d42908f8 ffff8801d4290870 ffff8801cf2e7660 [ 48.247283] ffffffff815653cb ffff8801d42908f8 0000000000000002 0000000000000000 [ 48.255257] Call Trace: [ 48.257825] [] dump_stack+0xc1/0x128 [ 48.263168] [] print_address_description+0x6c/0x234 [ 48.269823] [] kasan_report.cold.6+0x242/0x2fe [ 48.276030] [] ? __kernfs_remove+0x742/0x830 [ 48.282056] [] __asan_report_load2_noabort+0x14/0x20 [ 48.288779] [] __kernfs_remove+0x742/0x830 [ 48.294634] [] ? kernfs_remove_by_name_ns+0x54/0xb0 [ 48.301268] [] ? kernfs_next_descendant_post+0x2a0/0x2a0 [ 48.308337] [] ? kernfs_name_hash+0xb2/0xe0 [ 48.314275] [] ? kernfs_find_ns+0x1ba/0x330 [ 48.320216] [] kernfs_remove_by_name_ns+0x54/0xb0 [ 48.326679] [] sysfs_remove_link+0x4d/0x90 [ 48.332533] [] sysfs_slab_add+0x36/0x1d0 [ 48.338215] [] __kmem_cache_create+0x1d1/0x3d0 [ 48.344431] [] kmem_cache_create+0x1bc/0x2c0 [ 48.350462] [] recover_fsync_data+0x15b/0x1b70 [ 48.356665] [] ? proc_register+0x220/0x2f0 [ 48.362523] [] ? _raw_write_unlock+0x2c/0x50 [ 48.368556] [] ? proc_register+0x31/0x2f0 [ 48.374328] [] ? space_for_roll_forward+0xc0/0xc0 [ 48.380792] [] ? recover_orphan_inodes+0x6eb/0xef0 [ 48.387345] [] ? proc_mkdir+0x30/0x30 [ 48.392765] [] ? lockdep_init_map+0x105/0x4f0 [ 48.398885] [] ? remove_orphan_inode+0x30/0x30 [ 48.405089] [] f2fs_fill_super+0x22b6/0x5d00 [ 48.411120] [] ? vsnprintf+0x1a8/0x1840 [ 48.416717] [] ? vsprintf+0x40/0x40 [ 48.421966] [] ? f2fs_commit_super+0x3c0/0x3c0 [ 48.428169] [] ? set_blocksize+0x267/0x300 [ 48.434024] [] ? set_bdev_super+0x150/0x150 [ 48.439997] [] mount_bdev+0x2c7/0x390 [ 48.445424] [] ? f2fs_commit_super+0x3c0/0x3c0 [ 48.451640] [] f2fs_mount+0x34/0x40 [ 48.456887] [] mount_fs+0x28c/0x370 [ 48.462132] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 48.468507] [] ? ns_capable_common+0x12a/0x150 [ 48.474708] [] do_mount+0x3c9/0x2740 [ 48.480042] [] ? copy_mount_string+0x40/0x40 [ 48.486080] [] ? kasan_unpoison_shadow+0x35/0x50 [ 48.492455] [] ? kasan_kmalloc+0xc7/0xe0 [ 48.498138] [] ? kmem_cache_alloc_trace+0xfd/0x2b0 [ 48.504685] [] ? copy_mount_options+0x5f/0x320 [ 48.510891] [] ? copy_mount_options+0x1e5/0x320 [ 48.517179] [] SyS_mount+0xfe/0x110 [ 48.522426] [] ? copy_mnt_ns+0x8e0/0x8e0 [ 48.528107] [] do_syscall_64+0x1a6/0x490 [ 48.533788] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 48.540683] [ 48.542284] Allocated by task 4402: [ 48.545882] save_stack_trace+0x16/0x20 [ 48.549826] save_stack+0x43/0xd0 [ 48.553273] kasan_kmalloc+0xc7/0xe0 [ 48.556957] kasan_slab_alloc+0x12/0x20 [ 48.560901] kmem_cache_alloc+0xbe/0x290 [ 48.564931] __kernfs_new_node+0x6c/0x2b0 [ 48.569049] kernfs_new_node+0x80/0xe0 [ 48.572906] kernfs_create_dir_ns+0x3d/0x130 [ 48.577284] sysfs_create_dir_ns+0xbe/0x1c0 [ 48.581584] kobject_add_internal+0x1df/0x8a0 [ 48.586048] kobject_init_and_add+0xe7/0x140 [ 48.590425] sysfs_slab_add+0x60/0x1d0 [ 48.594279] __kmem_cache_create+0x1d1/0x3d0 [ 48.599509] kmem_cache_create+0x1bc/0x2c0 [ 48.603715] recover_fsync_data+0x15b/0x1b70 [ 48.608093] f2fs_fill_super+0x22b6/0x5d00 [ 48.612296] mount_bdev+0x2c7/0x390 [ 48.615894] f2fs_mount+0x34/0x40 [ 48.619314] mount_fs+0x28c/0x370 [ 48.622736] vfs_kern_mount.part.29+0xd1/0x3d0 [ 48.627285] do_mount+0x3c9/0x2740 [ 48.630795] SyS_mount+0xfe/0x110 [ 48.634219] do_syscall_64+0x1a6/0x490 [ 48.638077] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 48.643145] [ 48.644743] Freed by task 4394: [ 48.647996] save_stack_trace+0x16/0x20 [ 48.651940] save_stack+0x43/0xd0 [ 48.655360] kasan_slab_free+0x72/0xc0 [ 48.659217] kmem_cache_free+0xbe/0x310 [ 48.663160] kernfs_put+0x2f6/0x540 [ 48.666755] __kernfs_remove+0x365/0x830 [ 48.670789] kernfs_remove_by_name_ns+0x54/0xb0 [ 48.675434] sysfs_remove_link+0x4d/0x90 [ 48.679467] sysfs_slab_add+0x36/0x1d0 [ 48.683323] __kmem_cache_create+0x1d1/0x3d0 [ 48.687701] kmem_cache_create+0x1bc/0x2c0 [ 48.691908] recover_fsync_data+0x15b/0x1b70 [ 48.696288] f2fs_fill_super+0x22b6/0x5d00 [ 48.700492] mount_bdev+0x2c7/0x390 [ 48.704087] f2fs_mount+0x34/0x40 [ 48.707513] mount_fs+0x28c/0x370 [ 48.710936] vfs_kern_mount.part.29+0xd1/0x3d0 [ 48.715494] do_mount+0x3c9/0x2740 [ 48.719009] SyS_mount+0xfe/0x110 [ 48.722435] do_syscall_64+0x1a6/0x490 [ 48.726293] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 48.731361] [ 48.732962] The buggy address belongs to the object at ffff8801d4290870 [ 48.732962] which belongs to the cache kernfs_node_cache of size 152 [ 48.746109] The buggy address is located 136 bytes inside of [ 48.746109] 152-byte region [ffff8801d4290870, ffff8801d4290908) [ 48.757948] The buggy address belongs to the page: [ 48.762935] page:ffffea000750a400 count:1 mapcount:0 mapping: (null) index:0x0 [ 48.771165] flags: 0x8000000000000080(slab) [ 48.775453] page dumped because: kasan: bad access detected [ 48.781128] [ 48.782722] Memory state around the buggy address: [ 48.787620] ffff8801d4290780: fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 48.794948] ffff8801d4290800: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fb fb [ 48.802275] >ffff8801d4290880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 48.809603] ^ [ 48.816845] ffff8801d4290900: fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb [ 48.824173] ffff8801d4290980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 48.831498] ================================================================== [ 48.838824] Disabling lock debugging due to kernel taint [ 48.845257] Kernel panic - not syncing: panic_on_warn set ... [ 48.845257] [ 48.852634] CPU: 0 PID: 4394 Comm: syzkaller241258 Tainted: G B 4.9.95-g13cc540 #2 [ 48.861442] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.870773] ffff8801cf2e7588 ffffffff81eb0ba9 ffffffff841c4485 00000000ffffffff [ 48.878755] 0000000000000000 0000000000000000 ffff8801d4290870 ffff8801cf2e7648 [ 48.886742] ffffffff8141f945 0000000041b58ab3 ffffffff841b7b88 ffffffff8141f786 [ 48.894717] Call Trace: [ 48.897278] [] dump_stack+0xc1/0x128 [ 48.902612] [] panic+0x1bf/0x3bc [ 48.907600] [] ? add_taint.cold.6+0x16/0x16 [ 48.913542] [] ? ___preempt_schedule+0x16/0x18 [ 48.919745] [] kasan_end_report+0x47/0x4f [ 48.925514] [] kasan_report.cold.6+0x76/0x2fe [ 48.931773] [] ? __kernfs_remove+0x742/0x830 [ 48.937806] [] __asan_report_load2_noabort+0x14/0x20 [ 48.944530] [] __kernfs_remove+0x742/0x830 [ 48.950385] [] ? kernfs_remove_by_name_ns+0x54/0xb0 [ 48.957039] [] ? kernfs_next_descendant_post+0x2a0/0x2a0 [ 48.964110] [] ? kernfs_name_hash+0xb2/0xe0 [ 48.970051] [] ? kernfs_find_ns+0x1ba/0x330 [ 48.976006] [] kernfs_remove_by_name_ns+0x54/0xb0 [ 48.982470] [] sysfs_remove_link+0x4d/0x90 [ 48.988333] [] sysfs_slab_add+0x36/0x1d0 [ 48.994014] [] __kmem_cache_create+0x1d1/0x3d0 [ 49.000223] [] kmem_cache_create+0x1bc/0x2c0 [ 49.006252] [] recover_fsync_data+0x15b/0x1b70 [ 49.012455] [] ? proc_register+0x220/0x2f0 [ 49.018317] [] ? _raw_write_unlock+0x2c/0x50 [ 49.024527] [] ? proc_register+0x31/0x2f0 [ 49.030299] [] ? space_for_roll_forward+0xc0/0xc0 [ 49.036774] [] ? recover_orphan_inodes+0x6eb/0xef0 [ 49.043332] [] ? proc_mkdir+0x30/0x30 [ 49.048767] [] ? lockdep_init_map+0x105/0x4f0 [ 49.054881] [] ? remove_orphan_inode+0x30/0x30 [ 49.061082] [] f2fs_fill_super+0x22b6/0x5d00 [ 49.067112] [] ? vsnprintf+0x1a8/0x1840 [ 49.072709] [] ? vsprintf+0x40/0x40 [ 49.077958] [] ? f2fs_commit_super+0x3c0/0x3c0 [ 49.084163] [] ? set_blocksize+0x267/0x300 [ 49.090023] [] ? set_bdev_super+0x150/0x150 [ 49.095970] [] mount_bdev+0x2c7/0x390 [ 49.101393] [] ? f2fs_commit_super+0x3c0/0x3c0 [ 49.107594] [] f2fs_mount+0x34/0x40 [ 49.112842] [] mount_fs+0x28c/0x370 [ 49.118090] [] vfs_kern_mount.part.29+0xd1/0x3d0 [ 49.124466] [] ? ns_capable_common+0x12a/0x150 [ 49.130669] [] do_mount+0x3c9/0x2740 [ 49.136003] [] ? copy_mount_string+0x40/0x40 [ 49.142030] [] ? kasan_unpoison_shadow+0x35/0x50 [ 49.148404] [] ? kasan_kmalloc+0xc7/0xe0 [ 49.154086] [] ? kmem_cache_alloc_trace+0xfd/0x2b0 [ 49.160637] [] ? copy_mount_options+0x5f/0x320 [ 49.166838] [] ? copy_mount_options+0x1e5/0x320 [ 49.173127] [] SyS_mount+0xfe/0x110 [ 49.178373] [] ? copy_mnt_ns+0x8e0/0x8e0 [ 49.184057] [] do_syscall_64+0x1a6/0x490 [ 49.189740] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 49.197087] Dumping ftrace buffer: [ 49.200597] (ftrace buffer empty) [ 49.204285] Kernel Offset: disabled [ 49.207879] Rebooting in 86400 seconds..