@@ -153,8 +153,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- if (!IS_POSIXACL(path.dentry->d_inode))
- mode &= ~current_umask();
+ mode = mode_strip_umask(d_inode(path.dentry), mode);
error = security_path_mknod(&path, dentry, mode, dev);
if (!error)
error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
@@ -229,8 +228,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
dentry = kern_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- if (!IS_POSIXACL(path.dentry->d_inode))
- mode &= ~current_umask();
+ mode = mode_strip_umask(d_inode(path.dentry), mode);
error = security_path_mkdir(&path, dentry, mode);
if (!error)
error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
@@ -3103,25 +3103,6 @@ void unlock_rename(struct dentry *p1, struct dentry *p2)
}
EXPORT_SYMBOL(unlock_rename);
-/**
- * mode_strip_umask - handle vfs umask stripping
- * @dir: parent directory of the new inode
- * @mode: mode of the new inode to be created in @dir
- *
- * Umask stripping depends on whether or not the filesystem supports POSIX
- * ACLs. If the filesystem doesn't support it umask stripping is done directly
- * in here. If the filesystem does support POSIX ACLs umask stripping is
- * deferred until the filesystem calls posix_acl_create().
- *
- * Returns: mode
- */
-static inline umode_t mode_strip_umask(const struct inode *dir, umode_t mode)
-{
- if (!IS_POSIXACL(dir))
- mode &= ~current_umask();
- return mode;
-}
-
/**
* vfs_prepare_mode - prepare the mode to be used for a new inode
* @idmap: idmap of the mount the inode was found from
@@ -1071,7 +1071,7 @@ static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
sb->s_export_op = &nfs_export_ops;
break;
case 4:
- sb->s_flags |= SB_POSIXACL;
+ sb->s_iflags |= SB_I_NOUMASK;
sb->s_time_gran = 1;
sb->s_time_min = S64_MIN;
sb->s_time_max = S64_MAX;
@@ -1119,7 +1119,7 @@ extern int send_sigurg(struct fown_struct *fown);
#define SB_NOATIME BIT(10) /* Do not update access times. */
#define SB_NODIRATIME BIT(11) /* Do not update directory access times */
#define SB_SILENT BIT(15)
-#define SB_POSIXACL BIT(16) /* VFS does not apply the umask */
+#define SB_POSIXACL BIT(16) /* Supports POSIX ACLs */
#define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */
#define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */
#define SB_I_VERSION BIT(23) /* Update inode I_version field */
@@ -1166,6 +1166,7 @@ extern int send_sigurg(struct fown_struct *fown);
#define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
#define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
#define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */
+#define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */
/* Possible states of 'frozen' field */
enum {
@@ -92,6 +92,30 @@ extern struct dentry *lock_rename(struct dentry *, struct dentry *);
extern struct dentry *lock_rename_child(struct dentry *, struct dentry *);
extern void unlock_rename(struct dentry *, struct dentry *);
+/**
+ * mode_strip_umask - handle vfs umask stripping
+ * @dir: parent directory of the new inode
+ * @mode: mode of the new inode to be created in @dir
+ *
+ * In most filesystems, umask stripping depends on whether or not the
+ * filesystem supports POSIX ACLs. If the filesystem doesn't support it umask
+ * stripping is done directly in here. If the filesystem does support POSIX
+ * ACLs umask stripping is deferred until the filesystem calls
+ * posix_acl_create().
+ *
+ * Some filesystems (like NFSv4) also want to avoid umask stripping by the
+ * VFS, but don't support POSIX ACLs. Those filesystems can set SB_I_NOUMASK
+ * to get this effect without declaring that they support POSIX ACLs.
+ *
+ * Returns: mode
+ */
+static inline umode_t __must_check mode_strip_umask(const struct inode *dir, umode_t mode)
+{
+ if (!IS_POSIXACL(dir) && !(dir->i_sb->s_iflags & SB_I_NOUMASK))
+ mode &= ~current_umask();
+ return mode;
+}
+
extern int __must_check nd_jump_link(const struct path *path);
static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
SB_POSIXACL must be set when a filesystem supports POSIX ACLs, but NFSv4 also sets this flag to prevent the VFS from applying the umask on newly-created files. NFSv4 doesn't support POSIX ACLs however, which causes confusion when other subsystems try to test for them. Add a new SB_I_NOUMASK flag that allows filesystems to opt-in to umask stripping without advertising support for POSIX ACLs. Set the new flag on NFSv4 instead of SB_POSIXACL. Also, move mode_strip_umask to namei.h and convert init_mknod and init_mkdir to use it. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- Yet another approach to fixing this issue. I think this way is probably the best, since makes the purpose of these flags clearer, and stops NFS from relying on SB_POSIXACL to avoid umask stripping. --- Changes in v3: - move new flag to s_iflags - convert init_mkdir and init_mknod to use mode_strip_umask - Link to v2: https://lore.kernel.org/r/20230910-acl-fix-v2-1-38d6caa81419@kernel.org Changes in v2: - new approach: add a new SB_NOUMASK flag that NFSv4 can use instead of SB_POSIXACL - Link to v1: https://lore.kernel.org/r/20230908-acl-fix-v1-1-1e6b76c8dcc8@kernel.org --- fs/init.c | 6 ++---- fs/namei.c | 19 ------------------- fs/nfs/super.c | 2 +- include/linux/fs.h | 3 ++- include/linux/namei.h | 24 ++++++++++++++++++++++++ 5 files changed, 29 insertions(+), 25 deletions(-) --- base-commit: a48fa7efaf1161c1c898931fe4c7f0070964233a change-id: 20230908-acl-fix-6f8f86930f32 Best regards,