From: Al Viro
mainline inclusion
from mainline-5.14-rc1
commit ffb37ca3bd16ce6ea2df2f87fde9a31e94ebb54b
category: bugfix
issue: #I4NRS5
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Signed-off-by: Yu Changchun
---------------------------
... and provide file_open_root_mnt(), using the root of given mount.
Signed-off-by: Al Viro
Conflicts:
Documentation/filesystems/porting.rst
[ Non-bugfix 14e43bf4356126("vfs: don't unnecessarily clone
write access for writable fd") is not applied. ]
Signed-off-by: Zhihao Cheng
Reviewed-by: Zhang Yi
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
Documentation/filesystems/porting.rst | 9 +++++++++
arch/um/drivers/mconsole_kern.c | 2 +-
fs/coredump.c | 4 ++--
fs/fhandle.c | 2 +-
fs/internal.h | 2 +-
fs/kernel_read_file.c | 2 +-
fs/namei.c | 8 +++-----
fs/open.c | 4 ++--
fs/proc/proc_sysctl.c | 2 +-
include/linux/fs.h | 9 ++++++++-
kernel/usermode_driver.c | 2 +-
11 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 867036aa90b8..b00fb6313b58 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -865,3 +865,12 @@ no matter what. Everything is handled by the caller.
clone_private_mount() returns a longterm mount now, so the proper destructor of
its result is kern_unmount() or kern_unmount_array().
+
+---
+
+**mandatory**
+
+Calling conventions for file_open_root() changed; now it takes struct path *
+instead of passing mount and dentry separately. For callers that used to
+pass mnt_root> pair (i.e. the root of given mount), a new helper
+is provided - file_open_root_mnt(). In-tree users adjusted.
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index a2e680f7d39f..6a22ead31c5b 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -140,7 +140,7 @@ void mconsole_proc(struct mc_request *req)
mconsole_reply(req, "Proc not available", 1, 0);
goto out;
}
- file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY, 0);
+ file = file_open_root_mnt(mnt, ptr, O_RDONLY, 0);
if (IS_ERR(file)) {
mconsole_reply(req, "Failed to open file", 1, 0);
printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file));
diff --git a/fs/coredump.c b/fs/coredump.c
index c56a3bdce7cd..335c98787e66 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -755,8 +755,8 @@ void do_coredump(const kernel_siginfo_t *siginfo)
task_lock(&init_task);
get_fs_root(init_task.fs, &root);
task_unlock(&init_task);
- cprm.file = file_open_root(root.dentry, root.mnt,
- cn.corename, open_flags, 0600);
+ cprm.file = file_open_root(&root, cn.corename,
+ open_flags, 0600);
path_put(&root);
} else {
cprm.file = filp_open(cn.corename, open_flags, 0600);
diff --git a/fs/fhandle.c b/fs/fhandle.c
index 01263ffbc4c0..718defdf1e0e 100644
--- a/fs/fhandle.c
+++ b/fs/fhandle.c
@@ -229,7 +229,7 @@ static long do_handle_open(int mountdirfd, struct file_handle __user *ufh,
path_put(&path);
return fd;
}
- file = file_open_root(path.dentry, path.mnt, "", open_flag, 0);
+ file = file_open_root(&path, "", open_flag, 0);
if (IS_ERR(file)) {
put_unused_fd(fd);
retval = PTR_ERR(file);
diff --git a/fs/internal.h b/fs/internal.h
index 5155f6ce95c7..0d4f7e4e2f3a 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -128,7 +128,7 @@ struct open_flags {
};
extern struct file *do_filp_open(int dfd, struct filename *pathname,
const struct open_flags *op);
-extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
+extern struct file *do_file_open_root(const struct path *,
const char *, const struct open_flags *);
extern struct open_how build_open_how(int flags, umode_t mode);
extern int build_open_flags(const struct open_how *how, struct open_flags *op);
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index c84d87f558cb..1b07550485b9 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -160,7 +160,7 @@ int kernel_read_file_from_path_initns(const char *path, loff_t offset,
get_fs_root(init_task.fs, &root);
task_unlock(&init_task);
- file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
+ file = file_open_root(&root, path, O_RDONLY, 0);
path_put(&root);
if (IS_ERR(file))
return PTR_ERR(file);
diff --git a/fs/namei.c b/fs/namei.c
index 4c9d0c36545d..130aa5694f48 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3393,7 +3393,7 @@ struct file *do_filp_open(int dfd, struct filename *pathname,
return filp;
}
-struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
+struct file *do_file_open_root(const struct path *root,
const char *name, const struct open_flags *op)
{
struct nameidata nd;
@@ -3401,16 +3401,14 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
struct filename *filename;
int flags = op->lookup_flags | LOOKUP_ROOT;
- nd.root.mnt = mnt;
- nd.root.dentry = dentry;
-
- if (d_is_symlink(dentry) && op->intent & LOOKUP_OPEN)
+ if (d_is_symlink(root->dentry) && op->intent & LOOKUP_OPEN)
return ERR_PTR(-ELOOP);
filename = getname_kernel(name);
if (IS_ERR(filename))
return ERR_CAST(filename);
+ nd.root = *root;
set_nameidata(&nd, -1, filename);
file = path_openat(&nd, op, flags | LOOKUP_RCU);
if (unlikely(file == ERR_PTR(-ECHILD)))
diff --git a/fs/open.c b/fs/open.c
index 3aaaad47d9ca..7ce64c08bb40 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1149,7 +1149,7 @@ struct file *filp_open(const char *filename, int flags, umode_t mode)
}
EXPORT_SYMBOL(filp_open);
-struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
+struct file *file_open_root(const struct path *root,
const char *filename, int flags, umode_t mode)
{
struct open_flags op;
@@ -1157,7 +1157,7 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
int err = build_open_flags(&how, &op);
if (err)
return ERR_PTR(err);
- return do_file_open_root(dentry, mnt, filename, &op);
+ return do_file_open_root(root, filename, &op);
}
EXPORT_SYMBOL(file_open_root);
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 070d2df8ab9c..ffed75f833b7 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1803,7 +1803,7 @@ static int process_sysctl_arg(char *param, char *val,
panic("%s: Failed to allocate path for %s\n", __func__, param);
strreplace(path, '.', '/');
- file = file_open_root((*proc_mnt)->mnt_root, *proc_mnt, path, O_WRONLY, 0);
+ file = file_open_root_mnt(*proc_mnt, path, O_WRONLY, 0);
if (IS_ERR(file)) {
err = PTR_ERR(file);
if (err == -ENOENT)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c4e366a3226e..3de2e6c714aa 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -39,6 +39,7 @@
#include
#include
#include
+#include
#include
#include
@@ -2527,8 +2528,14 @@ extern long do_sys_open(int dfd, const char __user *filename, int flags,
umode_t mode);
extern struct file *file_open_name(struct filename *, int, umode_t);
extern struct file *filp_open(const char *, int, umode_t);
-extern struct file *file_open_root(struct dentry *, struct vfsmount *,
+extern struct file *file_open_root(const struct path *,
const char *, int, umode_t);
+static inline struct file *file_open_root_mnt(struct vfsmount *mnt,
+ const char *name, int flags, umode_t mode)
+{
+ return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root},
+ name, flags, mode);
+}
extern struct file * dentry_open(const struct path *, int, const struct cred *);
extern struct file * open_with_fake_path(const struct path *, int,
struct inode*, const struct cred *);
diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c
index bb7bb3b478ab..9dae1f648713 100644
--- a/kernel/usermode_driver.c
+++ b/kernel/usermode_driver.c
@@ -26,7 +26,7 @@ static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *na
if (IS_ERR(mnt))
return mnt;
- file = file_open_root(mnt->mnt_root, mnt, name, O_CREAT | O_WRONLY, 0700);
+ file = file_open_root_mnt(mnt, name, O_CREAT | O_WRONLY, 0700);
if (IS_ERR(file)) {
mntput(mnt);
return ERR_CAST(file);
--
2.25.1
