RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 000000000000074b R14: 00000000004ca182 R15: 0000000000000012 proc_fill_super: get root inode failed ================================================================== BUG: KASAN: use-after-free in fast_dput fs/dcache.c:727 [inline] BUG: KASAN: use-after-free in dput+0x53e/0xdf0 fs/dcache.c:846 Read of size 4 at addr ffff8880239aba10 by task syz-executor.3/2174 CPU: 0 PID: 2174 Comm: syz-executor.3 Not tainted 5.7.0-rc1-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 fast_dput fs/dcache.c:727 [inline] dput+0x53e/0xdf0 fs/dcache.c:846 proc_kill_sb+0x73/0xf0 fs/proc/root.c:195 deactivate_locked_super+0x8c/0xf0 fs/super.c:335 vfs_get_super+0x258/0x2d0 fs/super.c:1212 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2816 [inline] do_mount+0x1306/0x1b30 fs/namespace.c:3141 __do_sys_mount fs/namespace.c:3350 [inline] __se_sys_mount fs/namespace.c:3327 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3327 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c889 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa844447c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa8444486d4 RCX: 000000000045c889 RDX: 00000000200000c0 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 000000000000074b R14: 00000000004ca182 R15: 0000000000000012 Allocated by task 7245: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484 __d_alloc+0x2b/0x8e0 fs/dcache.c:1690 d_alloc_pseudo+0x19/0x70 fs/dcache.c:1819 alloc_file_pseudo+0xc6/0x250 fs/file_table.c:225 sock_alloc_file+0x4f/0x190 net/socket.c:411 sock_map_fd net/socket.c:435 [inline] __sys_socket+0x13d/0x200 net/socket.c:1530 __do_sys_socket net/socket.c:1535 [inline] __se_sys_socket net/socket.c:1533 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1533 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 7245: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7f/0x320 mm/slab.c:3694 __d_free fs/dcache.c:271 [inline] dentry_free fs/dcache.c:348 [inline] dentry_free+0xde/0x160 fs/dcache.c:336 __dentry_kill+0x442/0x5d0 fs/dcache.c:593 dentry_kill fs/dcache.c:686 [inline] dput+0x80c/0xdf0 fs/dcache.c:859 __fput+0x461/0x880 fs/file_table.c:293 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff8880239aba10 which belongs to the cache dentry of size 304 The buggy address is located 0 bytes inside of 304-byte region [ffff8880239aba10, ffff8880239abb40) The buggy address belongs to the page: page:ffffea00008e6ac0 refcount:1 mapcount:0 mapping:000000002d407e2a index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00008e5e08 ffffea00008e6248 ffff8880aa200540 raw: 0000000000000000 ffff8880239ab000 000000010000000b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880239ab900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880239ab980: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc >ffff8880239aba00: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880239aba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880239abb00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================