5.15-stable review patch. If anyone has any objections, please let me know.
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From: Christian Brauner brauner@kernel.org
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@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Message-Id: 20230313-fs-nfs-setgid-v2-1-9a59f436cfc0@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org [ Harshit: backport to 5.15.y] 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@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -235,5 +235,3 @@ int do_setxattr(struct user_namespace *m /* * 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 @@ -731,9 +731,7 @@ 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 @@ -3135,6 +3135,8 @@ 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);
extern void __insert_inode_hash(struct inode *, unsigned long hashval); static inline void insert_inode_hash(struct inode *inode)