Starting OpenBSD Secure Shell server... Starting Permit User Sessions... [ OK ] Started Permit User Sessions. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started OpenBSD Secure Shell server. Warning: Permanently added '10.128.0.159' (ECDSA) to the list of known hosts. executing program [* ] A start job is running for dev-ttyS0.device (8s / 1min 30s)[** ] A start job is running for dev-ttyS0.device (9s / 1min 30s)[*** ] A start job is running for dev-ttyS0.device (9s / 1min 30s)[ *** ] A start job is running for dev-ttyS0.device (10s / 1min 30s)[ *** ] A start job is running for dev-ttyS0.device (11s / 1min 30s)[ ***] A start job is running for dev-ttyS0.device (11s / 1min 30s)[ **] A start job is running for dev-ttyS0.device (12s / 1min 30s)[ 19.684568][ T22] audit: type=1400 audit(1616617230.648:8): avc: denied { execmem } for pid=336 comm="syz-executor102" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 19.707933][ T337] EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue [ 19.725636][ T342] ================================================================== [ 19.733743][ T342] BUG: KASAN: use-after-free in ext4_write_inline_data_end+0x500/0x8c0 [ 19.741979][ T342] Write of size 70 at addr ffff8881ebab3016 by task syz-executor102/342 [ 19.750286][ T342] [ 19.752608][ T342] CPU: 0 PID: 342 Comm: syz-executor102 Not tainted 5.4.107-syzkaller-00754-g32de11228337 #0 [ 19.762773][ T342] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.773257][ T342] Call Trace: [ 19.776549][ T342] dump_stack+0x1d8/0x24e [ 19.780866][ T342] ? __getblk_gfp+0x3a/0x750 [ 19.785453][ T342] ? show_regs_print_info+0x12/0x12 [ 19.790640][ T342] ? printk+0xcf/0x114 [ 19.794696][ T342] print_address_description+0x9b/0x650 [ 19.800237][ T342] ? devkmsg_release+0x11c/0x11c [ 19.805165][ T342] ? queue_me+0x1cd/0x3c0 [ 19.809490][ T342] __kasan_report+0x182/0x260 [ 19.814156][ T342] ? ext4_write_inline_data_end+0x500/0x8c0 [ 19.820061][ T342] kasan_report+0x30/0x60 [ 19.824411][ T342] check_memory_region+0x2a5/0x2e0 [ 19.829530][ T342] ? ext4_write_inline_data_end+0x500/0x8c0 [ 19.835410][ T342] memcpy+0x38/0x50 [ 19.839264][ T342] ext4_write_inline_data_end+0x500/0x8c0 [ 19.844984][ T342] ? ext4_prepare_inline_data+0x1f0/0x1f0 [ 19.850719][ T342] ext4_write_end+0x1d5/0xe50 [ 19.855500][ T342] ? ext4_da_write_end+0x9e/0xb90 [ 19.860518][ T342] ? ext4_da_write_begin+0x1010/0x1010 [ 19.865971][ T342] generic_perform_write+0x403/0x5a0 [ 19.871257][ T342] ? grab_cache_page_write_begin+0x90/0x90 [ 19.877057][ T342] ? file_remove_privs+0x630/0x630 [ 19.882168][ T342] ? down_write_trylock+0xd8/0x150 [ 19.887274][ T342] __generic_file_write_iter+0x239/0x480 [ 19.893004][ T342] ext4_file_write_iter+0x49e/0x10e0 [ 19.898296][ T342] ? ext4_file_read_iter+0x140/0x140 [ 19.903583][ T342] ? iov_iter_init+0x83/0x160 [ 19.908283][ T342] __vfs_write+0x5ec/0x780 [ 19.912698][ T342] ? __kernel_write+0x340/0x340 [ 19.917563][ T342] ? check_preemption_disabled+0x9e/0x330 [ 19.923270][ T342] ? debug_smp_processor_id+0x20/0x20 [ 19.928725][ T342] vfs_write+0x212/0x4e0 [ 19.932961][ T342] ksys_write+0x186/0x2b0 [ 19.937279][ T342] ? __ia32_sys_read+0x80/0x80 [ 19.942034][ T342] ? finish_task_switch+0x130/0x550 [ 19.947239][ T342] do_syscall_64+0xcb/0x1e0 [ 19.951757][ T342] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 19.957642][ T342] RIP: 0033:0x451fb9 [ 19.961532][ T342] Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 19.981207][ T342] RSP: 002b:00007f13d86f9208 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 19.989617][ T342] RAX: ffffffffffffffda RBX: 00000000004cc3f8 RCX: 0000000000451fb9 [ 19.997583][ T342] RDX: 0000000000000082 RSI: 0000000020000180 RDI: 0000000000000007 [ 20.005547][ T342] RBP: 00000000004cc3f0 R08: 0000000000000000 R09: 0000000000000000 [ 20.013537][ T342] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cc3fc [ 20.021498][ T342] R13: 00007fff922164bf R14: 00007f13d86f9300 R15: 0000000000022000 [ 20.029572][ T342] [ 20.031906][ T342] Allocated by task 288: [ 20.036142][ T342] __kasan_kmalloc+0x137/0x1e0 [ 20.040908][ T342] kmem_cache_alloc+0x115/0x290 [ 20.045743][ T342] getname_flags+0xba/0x640 [ 20.050323][ T342] do_sys_open+0x33e/0x7c0 [ 20.054727][ T342] do_syscall_64+0xcb/0x1e0 [ 20.059309][ T342] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 20.065178][ T342] [ 20.067491][ T342] Freed by task 288: [ 20.071378][ T342] __kasan_slab_free+0x18a/0x240 [ 20.076309][ T342] slab_free_freelist_hook+0x7b/0x150 [ 20.081671][ T342] kmem_cache_free+0xb8/0x5f0 [ 20.086509][ T342] do_sys_open+0x62e/0x7c0 [ 20.091868][ T342] do_syscall_64+0xcb/0x1e0 [ 20.096354][ T342] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 20.102249][ T342] [ 20.104564][ T342] The buggy address belongs to the object at ffff8881ebab2200 [ 20.104564][ T342] which belongs to the cache names_cache of size 4096 [ 20.118719][ T342] The buggy address is located 3606 bytes inside of [ 20.118719][ T342] 4096-byte region [ffff8881ebab2200, ffff8881ebab3200) [ 20.132258][ T342] The buggy address belongs to the page: [ 20.138595][ T342] page:ffffea0007aeac00 refcount:1 mapcount:0 mapping:ffff8881f5cfb680 index:0x0 compound_mapcount: 0 [ 20.149869][ T342] flags: 0x8000000000010200(slab|head) [ 20.155336][ T342] raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfb680 [ 20.163931][ T342] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 20.172511][ T342] page dumped because: kasan: bad access detected [ 20.178907][ T342] [ 20.181217][ T342] Memory state around the buggy address: [ 20.187352][ T342] ffff8881ebab2f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.195485][ T342] ffff8881ebab2f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.203643][ T342] >ffff8881ebab3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.212218][ T342] ^ [ 20.216797][ T342] ffff8881ebab3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.224937][ T342] ffff8881ebab3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory write to /proc/sys/vm/nr_overcommit_hugepages failed: No such file or directory [ 20.233065][ T342] ===================================