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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 12:45:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 12:45:26 -0700
commit7b871c7713d1eafc3a614883bbdf68ab1dffa883 (patch)
tree942e920ec617dbd23fafe1a368f2ec69203d152e
parente2e694b9e6f3ec7deeb233b6b0fe20b6a47b304b (diff)
parentd75b9fa053e4cd278281386d860c26fdbfbe9d03 (diff)
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Merge branch 'work.gfs2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull gfs2 setattr updates from Al Viro: "Make it possible for filesystems to use a generic 'may_setattr()' and switch gfs2 to using it" * 'work.gfs2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: gfs2: Switch to may_setattr in gfs2_setattr fs: Move notify_change permission checks into may_setattr
-rw-r--r--fs/attr.c50
-rw-r--r--fs/gfs2/inode.c4
-rw-r--r--include/linux/fs.h2
3 files changed, 35 insertions, 21 deletions
diff --git a/fs/attr.c b/fs/attr.c
index 87ef39db1c34..473d21b3a86d 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -249,6 +249,34 @@ void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode,
}
EXPORT_SYMBOL(setattr_copy);
+int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
+ unsigned int ia_valid)
+{
+ int error;
+
+ if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
+ if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+ return -EPERM;
+ }
+
+ /*
+ * If utimes(2) and friends are called with times == NULL (or both
+ * times are UTIME_NOW), then we need to check for write permission
+ */
+ if (ia_valid & ATTR_TOUCH) {
+ if (IS_IMMUTABLE(inode))
+ return -EPERM;
+
+ if (!inode_owner_or_capable(mnt_userns, inode)) {
+ error = inode_permission(mnt_userns, inode, MAY_WRITE);
+ if (error)
+ return error;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL(may_setattr);
+
/**
* notify_change - modify attributes of a filesytem object
* @mnt_userns: user namespace of the mount the inode was found from
@@ -290,25 +318,9 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
WARN_ON_ONCE(!inode_is_locked(inode));
- if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
- if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
- return -EPERM;
- }
-
- /*
- * If utimes(2) and friends are called with times == NULL (or both
- * times are UTIME_NOW), then we need to check for write permission
- */
- if (ia_valid & ATTR_TOUCH) {
- if (IS_IMMUTABLE(inode))
- return -EPERM;
-
- if (!inode_owner_or_capable(mnt_userns, inode)) {
- error = inode_permission(mnt_userns, inode, MAY_WRITE);
- if (error)
- return error;
- }
- }
+ error = may_setattr(mnt_userns, inode, ia_valid);
+ if (error)
+ return error;
if ((ia_valid & ATTR_MODE)) {
umode_t amode = attr->ia_mode;
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 6e15434b23ac..3130f85d2b3f 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1985,8 +1985,8 @@ static int gfs2_setattr(struct user_namespace *mnt_userns,
if (error)
goto out;
- error = -EPERM;
- if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+ error = may_setattr(&init_user_ns, inode, attr->ia_valid);
+ if (error)
goto error;
error = setattr_prepare(&init_user_ns, dentry, attr);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 29b355037c08..e7a633353fd2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3439,6 +3439,8 @@ extern int buffer_migrate_page_norefs(struct address_space *,
#define buffer_migrate_page_norefs NULL
#endif
+int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
+ unsigned int ia_valid);
int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *);
extern int inode_newsize_ok(const struct inode *, loff_t offset);
void setattr_copy(struct user_namespace *, struct inode *inode,