http://jfs.bkbits.net/linux-2.5
shaggy@austin.ibm.com|ChangeSet|20041201221757|59199 shaggy
# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/12/01 16:17:57-06:00 shaggy@austin.ibm.com
# JFS: add security and trusted xattrs
#
# Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
#
# fs/jfs/xattr.c
# 2004/12/01 16:17:46-06:00 shaggy@austin.ibm.com +55 -4
# Add security and trusted xattrs
#
# fs/Kconfig
# 2004/12/01 16:17:46-06:00 shaggy@austin.ibm.com +12 -0
# Add jfs security labels (xattrs)
#
# ChangeSet
# 2004/11/17 12:51:43-06:00 shaggy@austin.ibm.com
# JFS: fix race in jfs_commit_inode
#
# There was a race that resulted in old, deleted inodes being written
# to disk after the inode number had been reused. jfs_commit_inode
# needs to verify that the inode is still linked and dirty before
# committing it.
#
# Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
#
# fs/jfs/inode.c
# 2004/11/17 12:51:26-06:00 shaggy@austin.ibm.com +8 -3
# jfs_commit_inode needs to re-verify that inode is still linked
# and dirty
#
diff -Nru a/fs/Kconfig b/fs/Kconfig
--- a/fs/Kconfig 2004-12-12 18:20:49 -08:00
+++ b/fs/Kconfig 2004-12-12 18:20:49 -08:00
@@ -266,6 +266,18 @@
If you don't know what Access Control Lists are, say N
+config JFS_SECURITY
+ bool "JFS Security Labels"
+ depends on JFS_FS
+ help
+ Security labels support alternative access control models
+ implemented by security modules like SELinux. This option
+ enables an extended attribute handler for file security
+ labels in the jfs filesystem.
+
+ If you are not using a security module that requires using
+ extended attributes for file security labels, say N.
+
config JFS_DEBUG
bool "JFS debugging"
depends on JFS_FS
diff -Nru a/fs/jfs/inode.c b/fs/jfs/inode.c
--- a/fs/jfs/inode.c 2004-12-12 18:20:49 -08:00
+++ b/fs/jfs/inode.c 2004-12-12 18:20:49 -08:00
@@ -81,8 +81,7 @@
* Don't commit if inode has been committed since last being
* marked dirty, or if it has been deleted.
*/
- if (test_cflag(COMMIT_Nolink, inode) ||
- !test_cflag(COMMIT_Dirty, inode))
+ if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
return 0;
if (isReadOnly(inode)) {
@@ -100,7 +99,13 @@
tid = txBegin(inode->i_sb, COMMIT_INODE);
down(&JFS_IP(inode)->commit_sem);
- rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
+
+ /*
+ * Retest inode state after taking commit_sem
+ */
+ if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
+ rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
+
txEnd(tid);
up(&JFS_IP(inode)->commit_sem);
return rc;
diff -Nru a/fs/jfs/xattr.c b/fs/jfs/xattr.c
--- a/fs/jfs/xattr.c 2004-12-12 18:20:49 -08:00
+++ b/fs/jfs/xattr.c 2004-12-12 18:20:49 -08:00
@@ -91,6 +91,12 @@
#define XATTR_OS2_PREFIX "os2."
#define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
+/* XATTR_SECURITY_PREFIX is defined in include/linux/xattr.h */
+#define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)
+
+#define XATTR_TRUSTED_PREFIX "trusted."
+#define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)
+
/*
* These three routines are used to recognize on-disk extended attributes
* that are in a recognized namespace. If the attribute is not recognized,
@@ -111,6 +117,19 @@
!strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
return FALSE;
/*
+ * Check for "security."
+ */
+ if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
+ !strncmp(ea->name, XATTR_SECURITY_PREFIX,
+ XATTR_SECURITY_PREFIX_LEN))
+ return FALSE;
+ /*
+ * Check for "trusted."
+ */
+ if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
+ !strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
+ return FALSE;
+ /*
* Add any other valid namespace prefixes here
*/
@@ -770,6 +789,15 @@
*/
return can_set_system_xattr(inode, name, value, value_len);
+ if(strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0)
+ return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM);
+
+#ifdef CONFIG_JFS_SECURITY
+ if (strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)
+ != 0)
+ return 0; /* Leave it to the security module */
+#endif
+
if((strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) != 0) &&
(strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) != 0))
return -EOPNOTSUPP;
@@ -937,8 +965,17 @@
static int can_get_xattr(struct inode *inode, const char *name)
{
+#ifdef CONFIG_JFS_SECURITY
+ if(strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0)
+ return 0;
+#endif
+
+ if(strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0)
+ return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM);
+
if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
return 0;
+
return permission(inode, MAY_READ, NULL);
}
@@ -1021,6 +1058,16 @@
return err;
}
+/*
+ * No special permissions are needed to list attributes except for trusted.*
+ */
+static inline int can_list(struct jfs_ea *ea)
+{
+ return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
+ XATTR_TRUSTED_PREFIX_LEN) ||
+ capable(CAP_SYS_ADMIN));
+}
+
ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
{
struct inode *inode = dentry->d_inode;
@@ -1045,8 +1092,10 @@
ealist = (struct jfs_ea_list *) ea_buf.xattr;
/* compute required size of list */
- for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
- size += name_size(ea) + 1;
+ for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
+ if (can_list(ea))
+ size += name_size(ea) + 1;
+ }
if (!data)
goto release;
@@ -1059,8 +1108,10 @@
/* Copy attribute names to buffer */
buffer = data;
for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
- int namelen = copy_name(buffer, ea);
- buffer += namelen + 1;
+ if (can_list(ea)) {
+ int namelen = copy_name(buffer, ea);
+ buffer += namelen + 1;
+ }
}
release: