diff mbox series

[v3,2/4] fs/ext4/acl: apply umask if ACL support is disabled

Message ID 20200407142243.2032-2-mk@cm4all.com (mailing list archive)
State New, archived
Headers show
Series [v3,1/4] fs/posix_acl: apply umask if superblock disables ACL support | expand

Commit Message

Max Kellermann April 7, 2020, 2:22 p.m. UTC 
The function ext4_init_acl() calls posix_acl_create() which is
responsible for applying the umask.  But without
CONFIG_EXT4_FS_POSIX_ACL, ext4_init_acl() is an empty inline function,
and nobody applies the umask.

This fixes a bug which causes the umask to be ignored with O_TMPFILE
on ext4:

 https://github.com/MusicPlayerDaemon/MPD/issues/558
 https://bugs.gentoo.org/show_bug.cgi?id=686142#c3
 https://bugzilla.kernel.org/show_bug.cgi?id=203625

Signed-off-by: Max Kellermann <mk@cm4all.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Cc: stable@vger.kernel.org
---
 fs/ext4/acl.h | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Christoph Hellwig April 17, 2020, 7:50 a.m. UTC | #1 
This looks correct (modulo some minor coding style derivations),
but I think the better fix is to reuse the poix_acl_create
functionality rather than duplicating it.  Something like this:

diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 8c7bbf3e566d..6cff7cc31866 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -268,33 +268,17 @@ ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 /*
  * Initialize the ACLs of a new inode. Called from ext4_new_inode.
  *
- * dir->i_mutex: down
  * inode->i_mutex: up (access to inode is still exclusive)
  */
 int
-ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+ext4_init_acl(handle_t *handle, struct inode *inode, int type,
+		struct posix_acl *acl)
 {
-	struct posix_acl *default_acl, *acl;
-	int error;
+	int error = 0;
 
-	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
-	if (error)
-		return error;
-
-	if (default_acl) {
-		error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
-				       default_acl, XATTR_CREATE);
-		posix_acl_release(default_acl);
-	} else {
-		inode->i_default_acl = NULL;
-	}
 	if (acl) {
-		if (!error)
-			error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
-					       acl, XATTR_CREATE);
+		error = __ext4_set_acl(handle, inode, type, acl, XATTR_CREATE);
 		posix_acl_release(acl);
-	} else {
-		inode->i_acl = NULL;
 	}
 	return error;
 }
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 9b63f5416a2f..1e2927d14238 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -57,15 +57,16 @@ static inline int ext4_acl_count(size_t size)
 /* acl.c */
 struct posix_acl *ext4_get_acl(struct inode *inode, int type);
 int ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type);
-extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
+int ext4_init_acl(handle_t *handle, struct inode *inode, int type,
+		struct posix_acl *acl);
 
 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
 #include <linux/sched.h>
 #define ext4_get_acl NULL
 #define ext4_set_acl NULL
 
-static inline int
-ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+static inline int ext4_init_acl(handle_t *handle, struct inode *inode, int type,
+		struct posix_acl *acl)
 {
 	return 0;
 }
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index b420c9dc444d..32b03f6277c1 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -1168,7 +1168,17 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 	}
 
 	if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
-		err = ext4_init_acl(handle, inode, dir);
+		struct posix_acl *default_acl, *acl;
+
+		cache_no_acl(inode);
+		err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+		if (err)
+			goto fail_free_drop;
+		err = ext4_init_acl(handle, inode, ACL_TYPE_DEFAULT,
+				default_acl);
+		if (err)
+			goto fail_free_drop;
+		err = ext4_init_acl(handle, inode, ACL_TYPE_ACCESS, acl);
 		if (err)
 			goto fail_free_drop;
diff mbox series

Patch

diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 9b63f5416a2f..7f3b25b3fa6d 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -67,6 +67,11 @@  extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 static inline int
 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 {
+	/* usually, the umask is applied by posix_acl_create(), but if
+	   ext4 ACL support is disabled at compile time, we need to do
+	   it here, because posix_acl_create() will never be called */
+	inode->i_mode &= ~current_umask();
+
 	return 0;
 }
 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */