Unverified Commit 4f704d9a authored by Christian Brauner's avatar Christian Brauner
Browse files

nfs: use vfs setgid helper 



We've aligned setgid behavior over multiple kernel releases. The details
can be found in the following two merge messages:
cf619f89 ("Merge tag 'fs.ovl.setgid.v6.2')
426b4ca2 ("Merge tag 'fs.setgid.v6.0')
Consistent setgid stripping behavior is now encapsulated in the
setattr_should_drop_sgid() helper which is used by all filesystems that
strip setgid bits outside of vfs proper. Switch nfs to rely on this
helper as well. Without this patch the setgid stripping tests in
xfstests will fail.

Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Message-Id: <20230313-fs-nfs-setgid-v2-1-9a59f436cfc0@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent d98ffa1a

fs/attr.c

+1 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ int setattr_should_drop_sgid(struct mnt_idmap *idmap, 
		return ATTR_KILL_SGID;

	return 0;

}

EXPORT_SYMBOL(setattr_should_drop_sgid);



/**

 * setattr_should_drop_suidgid - determine whether the set{g,u}id bit needs to

fs/internal.h

+0 −2
Original line number Diff line number Diff line
@@ -259,8 +259,6 @@ ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *po 
/*

 * fs/attr.c

 */

int setattr_should_drop_sgid(struct mnt_idmap *idmap,

			     const struct inode *inode);

struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);

struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);

void mnt_idmap_put(struct mnt_idmap *idmap);

fs/nfs/inode.c

+1 −3
Original line number Diff line number Diff line
@@ -717,9 +717,7 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, 
		if ((attr->ia_valid & ATTR_KILL_SUID) != 0 &&

		    inode->i_mode & S_ISUID)

			inode->i_mode &= ~S_ISUID;

		if ((attr->ia_valid & ATTR_KILL_SGID) != 0 &&

		    (inode->i_mode & (S_ISGID | S_IXGRP)) ==

		     (S_ISGID | S_IXGRP))

		if (setattr_should_drop_sgid(&nop_mnt_idmap, inode))

			inode->i_mode &= ~S_ISGID;

		if ((attr->ia_valid & ATTR_MODE) != 0) {

			int mode = attr->ia_mode & S_IALLUGO;

include/linux/fs.h

+2 −0
Original line number Diff line number Diff line
@@ -2675,6 +2675,8 @@ extern struct inode *new_inode(struct super_block *sb); 
extern void free_inode_nonrcu(struct inode *inode);

extern int setattr_should_drop_suidgid(struct mnt_idmap *, struct inode *);

extern int file_remove_privs(struct file *);

int setattr_should_drop_sgid(struct mnt_idmap *idmap,

			     const struct inode *inode);



/*

 * This must be used for allocating filesystems specific inodes to set