R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000004c01fb R14: 00000000004cfe38 R15: 0000000000000022 proc_fill_super: get root inode failed ================================================================== Dev loop3: unable to read RDB block 1 BUG: KASAN: use-after-free in fast_dput fs/dcache.c:717 [inline] BUG: KASAN: use-after-free in dput.part.26+0x634/0x7a0 fs/dcache.c:836 Read of size 4 at addr ffff8801b8a4f880 by task syz-executor4/13430 CPU: 1 PID: 13430 Comm: syz-executor4 Not tainted 4.18.0-rc4-next-20180713+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 fast_dput fs/dcache.c:717 [inline] dput.part.26+0x634/0x7a0 fs/dcache.c:836 loop3: AHDI p2 p4 dput+0x15/0x20 fs/dcache.c:831 proc_kill_sb+0x125/0x1e0 fs/proc/root.c:198 loop3: partition table partially beyond EOD, truncated deactivate_locked_super+0x97/0x100 fs/super.c:328 vfs_get_super+0x20f/0x270 fs/super.c:1262 loop3: p2 start 2020327233 is beyond EOD, proc_get_tree+0x88/0xb0 fs/proc/root.c:159 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1743 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 truncated ksys_mount+0x12d/0x140 fs/namespace.c:3105 __do_sys_mount fs/namespace.c:3119 [inline] __se_sys_mount fs/namespace.c:3116 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455ab9 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f45a93d3c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f45a93d46d4 RCX: 0000000000455ab9 RDX: 0000000020000540 RSI: 0000000020000500 RDI: 00000000200004c0 RBP: 000000000072bea0 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000004c01fb R14: 00000000004cfe38 R15: 0000000000000022 Allocated by task 12981: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 __d_alloc+0xc8/0xd50 fs/dcache.c:1617 d_alloc+0x96/0x380 fs/dcache.c:1701 d_alloc_parallel+0x15a/0x1ea0 fs/dcache.c:2469 lookup_open+0x567/0x1b70 fs/namei.c:3169 do_last fs/namei.c:3346 [inline] path_openat+0x261e/0x5430 fs/namei.c:3568 do_filp_open+0x255/0x380 fs/namei.c:3605 do_sys_open+0x584/0x720 fs/open.c:1077 __do_sys_open fs/open.c:1095 [inline] __se_sys_open fs/open.c:1090 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1090 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12993: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 __d_free+0x20/0x30 fs/dcache.c:257 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf98/0x2860 kernel/rcu/tree.c:2864 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288 The buggy address belongs to the object at ffff8801b8a4f880 which belongs to the cache dentry(81:syz4) of size 288 The buggy address is located 0 bytes inside of 288-byte region [ffff8801b8a4f880, ffff8801b8a4f9a0) The buggy address belongs to the page: page:ffffea0006e293c0 count:1 mapcount:0 mapping:ffff8801cfeacc80 index:0xffff8801b8a4f040 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea000753ef48 ffffea0007242448 ffff8801cfeacc80 raw: ffff8801b8a4f040 ffff8801b8a4f040 000000010000000a ffff8801c7fd6280 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801c7fd6280 Memory state around the buggy address: ffff8801b8a4f780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b8a4f800: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801b8a4f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b8a4f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b8a4f980: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb ==================================================================