This patch is a simple cleanup which should probably be
applied to -mm (assuming I haven't messed it up). The next
patch is an experimental patch which will require userspace
support and is just RFC at this point.
>From 9fc0782de6e1287aaeebe8ad653b008f09b22c11 Mon Sep 17 00:00:00 2001
From: Serge E. Hallyn <[EMAIL PROTECTED]>
Date: Mon, 15 Oct 2007 17:33:24 -0400
Subject: [PATCH 1/2] capabilities: clean up file capability reading
Simplify the vfs_cap_data structure.
Also fix get_file_caps which was declaring
__le32 v1caps[XATTR_CAPS_SZ] on the stack, but
XATTR_CAPS_SZ is already * sizeof(__le32).
Signed-off-by: Serge E. Hallyn <[EMAIL PROTECTED]>
---
include/linux/capability.h | 6 ++----
security/commoncap.c | 23 +++++++++++++++--------
2 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/include/linux/capability.h b/include/linux/capability.h
index 7a8d7ad..bb017ed 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -56,10 +56,8 @@ typedef struct __user_cap_data_struct {
struct vfs_cap_data {
__u32 magic_etc; /* Little endian */
- struct {
- __u32 permitted; /* Little endian */
- __u32 inheritable; /* Little endian */
- } data[1];
+ __u32 permitted; /* Little endian */
+ __u32 inheritable; /* Little endian */
};
#ifdef __KERNEL__
diff --git a/security/commoncap.c b/security/commoncap.c
index 43f9027..542bbe9 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -190,7 +190,8 @@ int cap_inode_killpriv(struct dentry *dentry)
return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
}
-static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm,
+static inline int cap_from_disk(struct vfs_cap_data *caps,
+ struct linux_binprm *bprm,
int size)
{
__u32 magic_etc;
@@ -198,7 +199,7 @@ static inline int cap_from_disk(__le32 *caps, struct
linux_binprm *bprm,
if (size != XATTR_CAPS_SZ)
return -EINVAL;
- magic_etc = le32_to_cpu(caps[0]);
+ magic_etc = le32_to_cpu(caps->magic_etc);
switch ((magic_etc & VFS_CAP_REVISION_MASK)) {
case VFS_CAP_REVISION:
@@ -206,8 +207,8 @@ static inline int cap_from_disk(__le32 *caps, struct
linux_binprm *bprm,
bprm->cap_effective = true;
else
bprm->cap_effective = false;
- bprm->cap_permitted = to_cap_t( le32_to_cpu(caps[1]) );
- bprm->cap_inheritable = to_cap_t( le32_to_cpu(caps[2]) );
+ bprm->cap_permitted = to_cap_t( le32_to_cpu(caps->permitted) );
+ bprm->cap_inheritable = to_cap_t(
le32_to_cpu(caps->inheritable) );
return 0;
default:
return -EINVAL;
@@ -219,7 +220,7 @@ static int get_file_caps(struct linux_binprm *bprm)
{
struct dentry *dentry;
int rc = 0;
- __le32 v1caps[XATTR_CAPS_SZ];
+ struct vfs_cap_data incaps;
struct inode *inode;
if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) {
@@ -232,8 +233,14 @@ static int get_file_caps(struct linux_binprm *bprm)
if (!inode->i_op || !inode->i_op->getxattr)
goto out;
- rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &v1caps,
- XATTR_CAPS_SZ);
+ rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
+ if (rc > 0) {
+ if (rc == XATTR_CAPS_SZ)
+ rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS,
+ &incaps, XATTR_CAPS_SZ);
+ else
+ rc = -EINVAL;
+ }
if (rc == -ENODATA || rc == -EOPNOTSUPP) {
/* no data, that's ok */
rc = 0;
@@ -242,7 +249,7 @@ static int get_file_caps(struct linux_binprm *bprm)
if (rc < 0)
goto out;
- rc = cap_from_disk(v1caps, bprm, rc);
+ rc = cap_from_disk(&incaps, bprm, rc);
if (rc)
printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
__FUNCTION__, rc, bprm->filename);
--
1.5.1.1.GIT
-
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