On Wed, Oct 11, 2023 at 07:26:06PM +0200, Jan Kara wrote: > I don't think this is accurate. posix_acl_create() needs unmasked 'mode' > because instead of using current_umask() for masking it wants to use > whatever is stored in the ACLs as an umask. > > So I still think we need to keep umask handling in both posix_acl_create() > and vfs_prepare_mode(). But filesystem's only obligation would be to call > posix_acl_create() if the inode is IS_POSIXACL. No more caring about when > to apply umask and when not based on config or mount options. Ah, right, thanks for the clarification. I *think* the following patch in the ext4 dev branch (not yet in Linus's tree, but it should be in linux-next) should be harmless, though, right? And once we get the changes in vfs_prepare_mode() we can revert in ext4 --- or do folks I think I should just drop it from the ext4 dev branch now? Thanks, - Ted commit 484fd6c1de13b336806a967908a927cc0356e312 Author: Max Kellermann <max.kellermann@xxxxxxxxx> Date: Tue Sep 19 10:18:23 2023 +0200 ext4: apply umask if ACL support is disabled 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 Reviewed-by: "J. Bruce Fields" <bfields@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx> Link: https://lore.kernel.org/r/20230919081824.1096619-1-max.kellermann@xxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h index 0c5a79c3b5d4..ef4c19e5f570 100644 --- a/fs/ext4/acl.h +++ b/fs/ext4/acl.h @@ -68,6 +68,11 @@ 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 */