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 5.15.y]
Conflicts:
fs/internal.h -- minor conflcit 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>
---
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(-)
diff --git a/fs/attr.c b/fs/attr.c
index 0ca14cbd4b8b..28e953e86960 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -47,6 +47,7 @@ int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
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
diff --git a/fs/internal.h b/fs/internal.h
index 1ff8cfc94467..d241eaa0c58b 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -235,5 +235,3 @@ int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
/*
* fs/attr.c
*/
-int setattr_should_drop_sgid(struct user_namespace *mnt_userns,
- const struct inode *inode);
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e4524635a129..d8f01d222c49 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -731,9 +731,7 @@ 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(&init_user_ns, inode))
inode->i_mode &= ~S_ISGID;
if ((attr->ia_valid & ATTR_MODE) != 0) {
int mode = attr->ia_mode & S_IALLUGO;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c0dd2794e1ba..6bba7a58c95c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3135,6 +3135,8 @@ extern struct inode *new_inode(struct super_block *sb);
extern void free_inode_nonrcu(struct inode *inode);
extern int setattr_should_drop_suidgid(struct 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);
extern void __insert_inode_hash(struct inode *, unsigned long hashval);
static inline void insert_inode_hash(struct inode *inode)
--
2.34.1
