This is a note to let you know that I've just added the patch titled
fs: add file and path permissions helpers
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-add-file-and-path-permissions-helpers.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 21f3967455d95b6e829ff038626cc1b52dd959e5
Author: Christian Brauner <brauner@xxxxxxxxxx>
Date: Thu Jan 21 14:19:22 2021 +0100
fs: add file and path permissions helpers
[ Upstream commit 02f92b3868a1b34ab98464e76b0e4e060474ba10 ]
Add two simple helpers to check permissions on a file and path
respectively and convert over some callers. It simplifies quite a few
codepaths and also reduces the churn in later patches quite a bit.
Christoph also correctly points out that this makes codepaths (e.g.
ioctls) way easier to follow that would otherwise have to do more
complex argument passing than necessary.
Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@xxxxxxxxxx
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Suggested-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: James Morris <jamorris@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/init.c b/fs/init.c
index e9c320a48cf15..02723bea84990 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -49,7 +49,7 @@ int __init init_chdir(const char *filename)
error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
if (error)
return error;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
+ error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
if (!error)
set_fs_pwd(current->fs, &path);
path_put(&path);
@@ -64,7 +64,7 @@ int __init init_chroot(const char *filename)
error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
if (error)
return error;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
+ error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
error = -EPERM;
@@ -118,7 +118,7 @@ int __init init_eaccess(const char *filename)
error = kern_path(filename, LOOKUP_FOLLOW, &path);
if (error)
return error;
- error = inode_permission(d_inode(path.dentry), MAY_ACCESS);
+ error = path_permission(&path, MAY_ACCESS);
path_put(&path);
return error;
}
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 3e905b2e1b9c3..829ead2792dfb 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -702,7 +702,7 @@ static int fanotify_find_path(int dfd, const char __user *filename,
}
/* you can only watch an inode if you have read permissions on it */
- ret = inode_permission(path->dentry->d_inode, MAY_READ);
+ ret = path_permission(path, MAY_READ);
if (ret) {
path_put(path);
goto out;
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index ad8fb4bca6dc1..82fc0cf86a7c3 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -352,7 +352,7 @@ static int inotify_find_inode(const char __user *dirname, struct path *path,
if (error)
return error;
/* you can only watch an inode if you have read permissions on it */
- error = inode_permission(path->dentry->d_inode, MAY_READ);
+ error = path_permission(path, MAY_READ);
if (error) {
path_put(path);
return error;
diff --git a/fs/open.c b/fs/open.c
index 48933cbb75391..9f56ebacfbefe 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -492,7 +492,7 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
if (error)
goto out;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
+ error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
@@ -521,7 +521,7 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd)
if (!d_can_lookup(f.file->f_path.dentry))
goto out_putf;
- error = inode_permission(file_inode(f.file), MAY_EXEC | MAY_CHDIR);
+ error = file_permission(f.file, MAY_EXEC | MAY_CHDIR);
if (!error)
set_fs_pwd(current->fs, &f.file->f_path);
out_putf:
@@ -540,7 +540,7 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
if (error)
goto out;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
+ error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
diff --git a/fs/udf/file.c b/fs/udf/file.c
index e283a62701b83..25f7c915f22b7 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -181,7 +181,7 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
long old_block, new_block;
int result;
- if (inode_permission(inode, MAY_READ) != 0) {
+ if (file_permission(filp, MAY_READ) != 0) {
udf_debug("no permission to access inode %lu\n", inode->i_ino);
return -EPERM;
}
diff --git a/fs/verity/enable.c b/fs/verity/enable.c
index 5ceae66e1ae02..29becb66d0d88 100644
--- a/fs/verity/enable.c
+++ b/fs/verity/enable.c
@@ -369,7 +369,7 @@ int fsverity_ioctl_enable(struct file *filp, const void __user *uarg)
* has verity enabled, and to stabilize the data being hashed.
*/
- err = inode_permission(inode, MAY_WRITE);
+ err = file_permission(filp, MAY_WRITE);
if (err)
return err;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6de70634e5471..0974e8160f50c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2824,6 +2824,14 @@ static inline int bmap(struct inode *inode, sector_t *block)
extern int notify_change(struct dentry *, struct iattr *, struct inode **);
extern int inode_permission(struct inode *, int);
extern int generic_permission(struct inode *, int);
+static inline int file_permission(struct file *file, int mask)
+{
+ return inode_permission(file_inode(file), mask);
+}
+static inline int path_permission(const struct path *path, int mask)
+{
+ return inode_permission(d_inode(path->dentry), mask);
+}
extern int __check_sticky(struct inode *dir, struct inode *inode);
static inline bool execute_ok(struct inode *inode)
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 6b14b4c4068cc..5966013bc788b 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -507,7 +507,7 @@ static void *bpf_obj_do_get(const char __user *pathname,
return ERR_PTR(ret);
inode = d_backing_inode(path.dentry);
- ret = inode_permission(inode, ACC_MODE(flags));
+ ret = path_permission(&path, ACC_MODE(flags));
if (ret)
goto out;
diff --git a/kernel/sys.c b/kernel/sys.c
index efc213ae4c5ad..7a2cfb57fa9e7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1873,7 +1873,7 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
goto exit;
- err = inode_permission(inode, MAY_EXEC);
+ err = file_permission(exe.file, MAY_EXEC);
if (err)
goto exit;
diff --git a/mm/madvise.c b/mm/madvise.c
index f71fc88f0b331..a63aa04ec7fa3 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -543,7 +543,7 @@ static inline bool can_do_pageout(struct vm_area_struct *vma)
* opens a side channel.
*/
return inode_owner_or_capable(file_inode(vma->vm_file)) ||
- inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0;
+ file_permission(vma->vm_file, MAY_WRITE) == 0;
}
static long madvise_pageout(struct vm_area_struct *vma,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ddc8ed096deca..186ae9dba0fd5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4918,7 +4918,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
/* the process need read permission on control file */
/* AV: shouldn't we check that it's been opened for read instead? */
- ret = inode_permission(file_inode(cfile.file), MAY_READ);
+ ret = file_permission(cfile.file, MAY_READ);
if (ret < 0)
goto out_put_cfile;
diff --git a/mm/mincore.c b/mm/mincore.c
index 02db1a834021b..7bdb4673f776a 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -167,7 +167,7 @@ static inline bool can_do_mincore(struct vm_area_struct *vma)
* mappings, which opens a side channel.
*/
return inode_owner_or_capable(file_inode(vma->vm_file)) ||
- inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0;
+ file_permission(vma->vm_file, MAY_WRITE) == 0;
}
static const struct mm_walk_ops mincore_walk_ops = {
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 3ab726a668e8a..405bf3e6eb796 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -959,7 +959,7 @@ static struct sock *unix_find_other(struct net *net,
if (err)
goto fail;
inode = d_backing_inode(path.dentry);
- err = inode_permission(inode, MAY_WRITE);
+ err = path_permission(&path, MAY_WRITE);
if (err)
goto put_fail;
