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

From: Max Kellermann
Date: Tue Apr 07 2020 - 10:31:36 EST


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@xxxxxxxxxx>
Reviewed-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
fs/ext4/acl.h | 5 +++++
1 file changed, 5 insertions(+)

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 */
--
2.20.1