debugfs: inode: debugfs_create_dir uses mode permission from parent
Currently function debugfs_create_dir() creates a new
directory in the debugfs (usually mounted /sys/kernel/debug)
with permission rwxr-xr-x. This is hard coded.
Change this to use the parent directory permission.
Output before the patch:
root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
/sys/kernel/debug/
├── [drwxr-xr-x] bdi
├── [drwxr-xr-x] block
├── [drwxr-xr-x] dasd
├── [drwxr-xr-x] device_component
├── [drwxr-xr-x] extfrag
├── [drwxr-xr-x] hid
├── [drwxr-xr-x] kprobes
├── [drwxr-xr-x] kvm
├── [drwxr-xr-x] memblock
├── [drwxr-xr-x] pm_qos
├── [drwxr-xr-x] qdio
├── [drwxr-xr-x] s390
├── [drwxr-xr-x] s390dbf
└── [drwx------] tracing
14 directories
[root@s8360047 linux]#
Output after the patch:
[root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
sys/kernel/debug/
├── [drwx------] bdi
├── [drwx------] block
├── [drwx------] dasd
├── [drwx------] device_component
├── [drwx------] extfrag
├── [drwx------] hid
├── [drwx------] kprobes
├── [drwx------] kvm
├── [drwx------] memblock
├── [drwx------] pm_qos
├── [drwx------] qdio
├── [drwx------] s390
├── [drwx------] s390dbf
└── [drwx------] tracing
14 directories
[root@s8360047 linux]#
Here is the full diff output done with:
[root@s8360047 ~]# diff -u treefull.before treefull.after |
sed 's-^- # -' > treefull.diff
# --- treefull.before 2018-04-27 13:22:04.532824564 +0200
# +++ treefull.after 2018-04-27 13:24:12.106182062 +0200
# @@ -1,55 +1,55 @@
# /sys/kernel/debug/
# -├── [drwxr-xr-x] bdi
# -│ ├── [drwxr-xr-x] 1:0
# -│ ├── [drwxr-xr-x] 1:1
# -│ ├── [drwxr-xr-x] 1:10
# -│ ├── [drwxr-xr-x] 1:11
# -│ ├── [drwxr-xr-x] 1:12
# -│ ├── [drwxr-xr-x] 1:13
# -│ ├── [drwxr-xr-x] 1:14
# -│ ├── [drwxr-xr-x] 1:15
# -│ ├── [drwxr-xr-x] 1:2
# -│ ├── [drwxr-xr-x] 1:3
# -│ ├── [drwxr-xr-x] 1:4
# -│ ├── [drwxr-xr-x] 1:5
# -│ ├── [drwxr-xr-x] 1:6
# -│ ├── [drwxr-xr-x] 1:7
# -│ ├── [drwxr-xr-x] 1:8
# -│ ├── [drwxr-xr-x] 1:9
# -│ └── [drwxr-xr-x] 94:0
# -├── [drwxr-xr-x] block
# -├── [drwxr-xr-x] dasd
# -│ ├── [drwxr-xr-x] 0.0.e18a
# -│ ├── [drwxr-xr-x] dasda
# -│ └── [drwxr-xr-x] global
# -├── [drwxr-xr-x] device_component
# -├── [drwxr-xr-x] extfrag
# -├── [drwxr-xr-x] hid
# -├── [drwxr-xr-x] kprobes
# -├── [drwxr-xr-x] kvm
# -├── [drwxr-xr-x] memblock
# -├── [drwxr-xr-x] pm_qos
# -├── [drwxr-xr-x] qdio
# -│ └── [drwxr-xr-x] 0.0.f5f2
# -├── [drwxr-xr-x] s390
# -│ └── [drwxr-xr-x] stsi
# -├── [drwxr-xr-x] s390dbf
# -│ ├── [drwxr-xr-x] 0.0.e18a
# -│ ├── [drwxr-xr-x] cio_crw
# -│ ├── [drwxr-xr-x] cio_msg
# -│ ├── [drwxr-xr-x] cio_trace
# -│ ├── [drwxr-xr-x] dasd
# -│ ├── [drwxr-xr-x] kvm-trace
# -│ ├── [drwxr-xr-x] lgr
# -│ ├── [drwxr-xr-x] qdio_0.0.f5f2
# -│ ├── [drwxr-xr-x] qdio_error
# -│ ├── [drwxr-xr-x] qdio_setup
# -│ ├── [drwxr-xr-x] qeth_card_0.0.f5f0
# -│ ├── [drwxr-xr-x] qeth_control
# -│ ├── [drwxr-xr-x] qeth_msg
# -│ ├── [drwxr-xr-x] qeth_setup
# -│ ├── [drwxr-xr-x] vmcp
# -│ └── [drwxr-xr-x] vmur
# +├── [drwx------] bdi
# +│ ├── [drwx------] 1:0
# +│ ├── [drwx------] 1:1
# +│ ├── [drwx------] 1:10
# +│ ├── [drwx------] 1:11
# +│ ├── [drwx------] 1:12
# +│ ├── [drwx------] 1:13
# +│ ├── [drwx------] 1:14
# +│ ├── [drwx------] 1:15
# +│ ├── [drwx------] 1:2
# +│ ├── [drwx------] 1:3
# +│ ├── [drwx------] 1:4
# +│ ├── [drwx------] 1:5
# +│ ├── [drwx------] 1:6
# +│ ├── [drwx------] 1:7
# +│ ├── [drwx------] 1:8
# +│ ├── [drwx------] 1:9
# +│ └── [drwx------] 94:0
# +├── [drwx------] block
# +├── [drwx------] dasd
# +│ ├── [drwx------] 0.0.e18a
# +│ ├── [drwx------] dasda
# +│ └── [drwx------] global
# +├── [drwx------] device_component
# +├── [drwx------] extfrag
# +├── [drwx------] hid
# +├── [drwx------] kprobes
# +├── [drwx------] kvm
# +├── [drwx------] memblock
# +├── [drwx------] pm_qos
# +├── [drwx------] qdio
# +│ └── [drwx------] 0.0.f5f2
# +├── [drwx------] s390
# +│ └── [drwx------] stsi
# +├── [drwx------] s390dbf
# +│ ├── [drwx------] 0.0.e18a
# +│ ├── [drwx------] cio_crw
# +│ ├── [drwx------] cio_msg
# +│ ├── [drwx------] cio_trace
# +│ ├── [drwx------] dasd
# +│ ├── [drwx------] kvm-trace
# +│ ├── [drwx------] lgr
# +│ ├── [drwx------] qdio_0.0.f5f2
# +│ ├── [drwx------] qdio_error
# +│ ├── [drwx------] qdio_setup
# +│ ├── [drwx------] qeth_card_0.0.f5f0
# +│ ├── [drwx------] qeth_control
# +│ ├── [drwx------] qeth_msg
# +│ ├── [drwx------] qeth_setup
# +│ ├── [drwx------] vmcp
# +│ └── [drwx------] vmur
# └── [drwx------] tracing
# ├── [drwxr-xr-x] events
# │ ├── [drwxr-xr-x] alarmtimer
Fixes: edac65eaf8d5c ("debugfs: take mode-dependent parts of debugfs_get_inode() into callers")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 13b0135..a913b12 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -512,7 +512,9 @@
if (unlikely(!inode))
return failed_creating(dentry);
- inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ if (!parent)
+ parent = debugfs_mount->mnt_root;
+ inode->i_mode = S_IFDIR | ((d_inode(parent)->i_mode & 0770));
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;