6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Christian Brauner <brauner@xxxxxxxxxx>
commit 4f704d9a8352f5c0a8fcdb6213b934630342bd44 upstream.
We've aligned setgid behavior over multiple kernel releases. The details
can be found in the following two merge messages:
cf619f891971 ("Merge tag 'fs.ovl.setgid.v6.2')
426b4ca2d6a5 ("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: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Message-Id: <20230313-fs-nfs-setgid-v2-1-9a59f436cfc0@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
[ Harshit: backport to 6.1.y:
fs/internal.h -- minor conflict due to code change differences.
include/linux/fs.h -- Used struct user_namespace *mnt_userns
instead of struct mnt_idmap *idmap
fs/nfs/inode.c -- Used init_user_ns instead of nop_mnt_idmap ]
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/attr.c | 1 +
fs/internal.h | 2 --
fs/nfs/inode.c | 4 +---
include/linux/fs.h | 2 ++
4 files changed, 4 insertions(+), 5 deletions(-)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -47,6 +47,7 @@ int setattr_should_drop_sgid(struct user
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
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -242,5 +242,3 @@ ssize_t __kernel_write_iter(struct file
/*
* fs/attr.c
*/
-int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
- const struct inode *inode);
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -717,9 +717,7 @@ void nfs_setattr_update_inode(struct ino
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(&init_user_ns, inode))
inode->i_mode &= ~S_ISGID;
if ((attr->ia_valid & ATTR_MODE) != 0) {
int mode = attr->ia_mode & S_IALLUGO;
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3120,6 +3120,8 @@ extern struct inode *new_inode(struct su
extern void free_inode_nonrcu(struct inode *inode);
extern int setattr_should_drop_suidgid(struct user_namespace *, struct inode *);
extern int file_remove_privs(struct file *);
+int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
+ const struct inode *inode);
/*
* This must be used for allocating filesystems specific inodes to set
