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 ================================================================== fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0xa/0x11 lib/fault-inject.c:149 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 ffff8801a7b8c4a0 by task syz-executor287/4482 __should_failslab+0x124/0x180 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1557 slab_pre_alloc_hook mm/slab.h:423 [inline] slab_alloc mm/slab.c:3378 [inline] __do_kmalloc mm/slab.c:3716 [inline] __kmalloc+0x2c8/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] kzalloc include/linux/slab.h:707 [inline] prealloc_shrinker+0x124/0x450 mm/vmscan.c:361 register_shrinker+0x17/0x40 mm/vmscan.c:413 sget_fc+0x778/0x960 fs/super.c:562 vfs_get_super+0x6e/0x270 fs/super.c:1263 proc_get_tree+0x88/0xb0 fs/proc/root.c:159 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 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: 0033:0x441d79 Code: e8 6c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 cb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe4c8551b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441d79 RDX: 0000000020000540 RSI: 0000000020000500 RDI: 00000000200004c0 RBP: 00007ffe4c8551d0 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 CPU: 0 PID: 4482 Comm: syz-executor287 Not tainted 4.18.0-rc3-next-20180706+ #1 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 dput+0x15/0x20 fs/dcache.c:831 proc_kill_sb+0x125/0x1e0 fs/proc/root.c:198 deactivate_locked_super+0x97/0x100 fs/super.c:328 vfs_get_super+0x20f/0x270 fs/super.c:1270 proc_get_tree+0x88/0xb0 fs/proc/root.c:159 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 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: 0033:0x441d79 Code: e8 6c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 cb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe4c8551b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441d79 RDX: 0000000020000540 RSI: 0000000020000500 RDI: 00000000200004c0 RBP: 00007ffe4c8551d0 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4473: 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_name+0xbb/0x120 fs/dcache.c:1755 proc_setup_self+0xe1/0x3af fs/proc/self.c:43 proc_fill_super+0x37e/0x630 fs/proc/root.c:133 vfs_get_super+0x15e/0x270 fs/super.c:1268 proc_get_tree+0x88/0xb0 fs/proc/root.c:159 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 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 Freed by task 4474: 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:258 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2878 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2845 [inline] rcu_process_callbacks+0xe01/0x2810 kernel/rcu/tree.c:2862 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288 The buggy address belongs to the object at ffff8801a7b8c4a0 which belongs to the cache dentry(17:syz4) of size 288 The buggy address is located 0 bytes inside of 288-byte region [ffff8801a7b8c4a0, ffff8801a7b8c5c0) The buggy address belongs to the page: page:ffffea00069ee300 count:1 mapcount:0 mapping:ffff8801ccf543c0 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d4348948 ffffea00069ee788 ffff8801ccf543c0 raw: 0000000000000000 ffff8801a7b8c080 000000010000000b ffff8801ab42c3c0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801ab42c3c0 Memory state around the buggy address: ffff8801a7b8c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801a7b8c400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801a7b8c480: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801a7b8c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801a7b8c580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================