Subject: + userns-relax-the-posix_acl_valid-checks.patch added to -mm tree
To: agruen@xxxxxxxxxx,adilger.kernel@xxxxxxxxx,ebiederm@xxxxxxxxxxxx,hch@xxxxxxxxxxxxx,jack@xxxxxxx,tytso@xxxxxxx,viro@xxxxxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 07 Jan 2014 15:57:21 -0800
The patch titled
Subject: userns: relax the posix_acl_valid() checks
has been added to the -mm tree. Its filename is
userns-relax-the-posix_acl_valid-checks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userns-relax-the-posix_acl_valid-checks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userns-relax-the-posix_acl_valid-checks.patch
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From: Andreas Gruenbacher <agruen@xxxxxxxxxx>
Subject: userns: relax the posix_acl_valid() checks
So far, POSIX ACLs are using a canonical representation that keeps all ACL
entries in a strict order; the ACL_USER and ACL_GROUP entries for specific
users and groups are ordered by user and group identifier, respectively.
The user-space code provides ACL entries in this order; the kernel
verifies that the ACL entry order is correct in posix_acl_valid().
User namespaces allow to arbitrary map user and group identifiers which
can cause the ACL_USER and ACL_GROUP entry order to differ between user
space and the kernel; posix_acl_valid() would then fail.
Work around this by allowing ACL_USER and ACL_GROUP entries to be in any
order in the kernel. The effect is only minor: file permission checks
will pick the first matching ACL_USER entry, and check all matching
ACL_GROUP entries.
(The libacl user-space library and getfacl / setfacl tools will not create
ACLs with duplicate user or group idenfifiers; they will handle ACLs with
entries in an arbitrary order correctly.)
Signed-off-by: Andreas Gruenbacher <agruen@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Theodore Tso <tytso@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/posix_acl.c | 10 ----------
1 file changed, 10 deletions(-)
diff -puN fs/posix_acl.c~userns-relax-the-posix_acl_valid-checks fs/posix_acl.c
--- a/fs/posix_acl.c~userns-relax-the-posix_acl_valid-checks
+++ a/fs/posix_acl.c
@@ -149,8 +149,6 @@ posix_acl_valid(const struct posix_acl *
{
const struct posix_acl_entry *pa, *pe;
int state = ACL_USER_OBJ;
- kuid_t prev_uid = INVALID_UID;
- kgid_t prev_gid = INVALID_GID;
int needs_mask = 0;
FOREACH_ACL_ENTRY(pa, acl, pe) {
@@ -169,10 +167,6 @@ posix_acl_valid(const struct posix_acl *
return -EINVAL;
if (!uid_valid(pa->e_uid))
return -EINVAL;
- if (uid_valid(prev_uid) &&
- uid_lte(pa->e_uid, prev_uid))
- return -EINVAL;
- prev_uid = pa->e_uid;
needs_mask = 1;
break;
@@ -188,10 +182,6 @@ posix_acl_valid(const struct posix_acl *
return -EINVAL;
if (!gid_valid(pa->e_gid))
return -EINVAL;
- if (gid_valid(prev_gid) &&
- gid_lte(pa->e_gid, prev_gid))
- return -EINVAL;
- prev_gid = pa->e_gid;
needs_mask = 1;
break;
_
Patches currently in -mm which might be from agruen@xxxxxxxxxx are
userns-relax-the-posix_acl_valid-checks.patch
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