This is a note to let you know that I've just added the patch titled
eCryptfs: Copy up POSIX ACL and read-only flags from lower mount
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ecryptfs-copy-up-posix-acl-and-read-only-flags-from-lower-mount.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 069ddcda37b2cf5bb4b6031a944c0e9359213262 Mon Sep 17 00:00:00 2001
From: Tyler Hicks <[email protected]>
Date: Mon, 11 Jun 2012 15:42:32 -0700
Subject: eCryptfs: Copy up POSIX ACL and read-only flags from lower mount
From: Tyler Hicks <[email protected]>
commit 069ddcda37b2cf5bb4b6031a944c0e9359213262 upstream.
When the eCryptfs mount options do not include '-o acl', but the lower
filesystem's mount options do include 'acl', the MS_POSIXACL flag is not
flipped on in the eCryptfs super block flags. This flag is what the VFS
checks in do_last() when deciding if the current umask should be applied
to a newly created inode's mode or not. When a default POSIX ACL mask is
set on a directory, the current umask is incorrectly applied to new
inodes created in the directory. This patch ignores the MS_POSIXACL flag
passed into ecryptfs_mount() and sets the flag on the eCryptfs super
block depending on the flag's presence on the lower super block.
Additionally, it is incorrect to allow a writeable eCryptfs mount on top
of a read-only lower mount. This missing check did not allow writes to
the read-only lower mount because permissions checks are still performed
on the lower filesystem's objects but it is best to simply not allow a
rw mount on top of ro mount. However, a ro eCryptfs mount on top of a rw
mount is valid and still allowed.
https://launchpad.net/bugs/1009207
Signed-off-by: Tyler Hicks <[email protected]>
Reported-by: Stefan Beller <[email protected]>
Cc: John Johansen <[email protected]>
Cc: Herton Ronaldo Krzesinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/ecryptfs/main.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -505,7 +505,6 @@ static struct dentry *ecryptfs_mount(str
goto out;
}
- s->s_flags = flags;
rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
if (rc)
goto out1;
@@ -541,6 +540,15 @@ static struct dentry *ecryptfs_mount(str
}
ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
+
+ /**
+ * Set the POSIX ACL flag based on whether they're enabled in the lower
+ * mount. Force a read-only eCryptfs mount if the lower mount is ro.
+ * Allow a ro eCryptfs mount even when the lower mount is rw.
+ */
+ s->s_flags = flags & ~MS_POSIXACL;
+ s->s_flags |= path.dentry->d_sb->s_flags & (MS_RDONLY | MS_POSIXACL);
+
s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
s->s_blocksize = path.dentry->d_sb->s_blocksize;
s->s_magic = ECRYPTFS_SUPER_MAGIC;
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/ecryptfs-copy-up-posix-acl-and-read-only-flags-from-lower-mount.patch
queue-3.0/ecryptfs-check-for-ecryptfs-cipher-support-at-mount.patch
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