Re: [SELINUX] Handle fuse binary mount data.
From: James Morris
Date: Sun Feb 29 2004 - 20:27:00 EST
On Sun, 29 Feb 2004, Andrew Morton wrote:
> Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> > Umm, binary mount data is bad enough, but hardcoding filesystem-depend code
> > in selinux is just bogus..
>
> Yes, it's rather awkward.
>
> Could we do something such as passing a new mount flag in from userspace?
> Add a new flag alongside MS_SYNCHRONOUS, MS_REMOUNT and friends?
It seems more like a property of the filesystem type: perhaps add
FS_BINARY_MOUNTDATA to fs_flags for such filesystems, per the patch below.
We also need to change one of the LSM hook arguments.
diff -urN -X dontdiff linux-2.6.3-mm4.o/fs/afs/super.c linux-2.6.3-mm4.w/fs/afs/super.c
--- linux-2.6.3-mm4.o/fs/afs/super.c 2004-02-04 08:39:05.000000000 -0500
+++ linux-2.6.3-mm4.w/fs/afs/super.c 2004-02-29 19:50:28.797502696 -0500
@@ -53,6 +53,7 @@
.name = "afs",
.get_sb = afs_get_sb,
.kill_sb = kill_anon_super,
+ .fs_flags = FS_BINARY_MOUNTDATA,
};
static struct super_operations afs_super_ops = {
diff -urN -X dontdiff linux-2.6.3-mm4.o/fs/coda/inode.c linux-2.6.3-mm4.w/fs/coda/inode.c
--- linux-2.6.3-mm4.o/fs/coda/inode.c 2003-09-27 20:50:20.000000000 -0400
+++ linux-2.6.3-mm4.w/fs/coda/inode.c 2004-02-29 19:49:14.272832168 -0500
@@ -306,5 +306,6 @@
.name = "coda",
.get_sb = coda_get_sb,
.kill_sb = kill_anon_super,
+ .fs_flags = FS_BINARY_MOUNTDATA,
};
diff -urN -X dontdiff linux-2.6.3-mm4.o/fs/nfs/inode.c linux-2.6.3-mm4.w/fs/nfs/inode.c
--- linux-2.6.3-mm4.o/fs/nfs/inode.c 2004-02-25 22:42:12.000000000 -0500
+++ linux-2.6.3-mm4.w/fs/nfs/inode.c 2004-02-29 19:48:24.350421528 -0500
@@ -1406,7 +1406,7 @@
.name = "nfs",
.get_sb = nfs_get_sb,
.kill_sb = nfs_kill_super,
- .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT,
+ .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
#ifdef CONFIG_NFS_V4
@@ -1720,7 +1720,7 @@
.name = "nfs4",
.get_sb = nfs4_get_sb,
.kill_sb = nfs_kill_super,
- .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT,
+ .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};
#define nfs4_zero_state(nfsi) \
diff -urN -X dontdiff linux-2.6.3-mm4.o/fs/smbfs/inode.c linux-2.6.3-mm4.w/fs/smbfs/inode.c
--- linux-2.6.3-mm4.o/fs/smbfs/inode.c 2003-10-15 08:53:19.000000000 -0400
+++ linux-2.6.3-mm4.w/fs/smbfs/inode.c 2004-02-29 19:50:58.172037088 -0500
@@ -778,6 +778,7 @@
.name = "smbfs",
.get_sb = smb_get_sb,
.kill_sb = kill_anon_super,
+ .fs_flags = FS_BINARY_MOUNTDATA,
};
static int __init init_smb_fs(void)
diff -urN -X dontdiff linux-2.6.3-mm4.o/fs/super.c linux-2.6.3-mm4.w/fs/super.c
--- linux-2.6.3-mm4.o/fs/super.c 2004-02-25 22:42:12.000000000 -0500
+++ linux-2.6.3-mm4.w/fs/super.c 2004-02-29 19:56:03.687591664 -0500
@@ -746,7 +746,7 @@
goto out_mnt;
}
- error = security_sb_copy_data(fstype, data, secdata);
+ error = security_sb_copy_data(type, data, secdata);
if (error) {
sb = ERR_PTR(error);
goto out_free_secdata;
diff -urN -X dontdiff linux-2.6.3-mm4.o/include/linux/fs.h linux-2.6.3-mm4.w/include/linux/fs.h
--- linux-2.6.3-mm4.o/include/linux/fs.h 2004-02-25 22:42:14.000000000 -0500
+++ linux-2.6.3-mm4.w/include/linux/fs.h 2004-02-29 19:43:33.922573272 -0500
@@ -89,6 +89,7 @@
/* public flags for file_system_type */
#define FS_REQUIRES_DEV 1
+#define FS_BINARY_MOUNTDATA 2
#define FS_REVAL_DOT 16384 /* Check the paths ".", ".." for staleness */
#define FS_ODD_RENAME 32768 /* Temporary stuff; will go away as soon
* as nfs_rename() will be cleaned up
diff -urN -X dontdiff linux-2.6.3-mm4.o/include/linux/security.h linux-2.6.3-mm4.w/include/linux/security.h
--- linux-2.6.3-mm4.o/include/linux/security.h 2004-02-25 22:42:14.000000000 -0500
+++ linux-2.6.3-mm4.w/include/linux/security.h 2004-02-29 19:57:58.125194504 -0500
@@ -177,7 +177,7 @@
* options cleanly (a filesystem may modify the data e.g. with strsep()).
* This also allows the original mount data to be stripped of security-
* specific options to avoid having to make filesystems aware of them.
- * @fstype the type of filesystem being mounted.
+ * @type the type of filesystem being mounted.
* @orig the original mount data copied from userspace.
* @copy copied data which will be passed to the security module.
* Returns 0 if the copy was successful.
@@ -1033,7 +1033,8 @@
int (*sb_alloc_security) (struct super_block * sb);
void (*sb_free_security) (struct super_block * sb);
- int (*sb_copy_data)(const char *fstype, void *orig, void *copy);
+ int (*sb_copy_data)(struct file_system_type *type,
+ void *orig, void *copy);
int (*sb_kern_mount) (struct super_block *sb, void *data);
int (*sb_statfs) (struct super_block * sb);
int (*sb_mount) (char *dev_name, struct nameidata * nd,
@@ -1318,9 +1319,10 @@
security_ops->sb_free_security (sb);
}
-static inline int security_sb_copy_data (const char *fstype, void *orig, void *copy)
+static inline int security_sb_copy_data (struct file_system_type *type,
+ void *orig, void *copy)
{
- return security_ops->sb_copy_data (fstype, orig, copy);
+ return security_ops->sb_copy_data (type, orig, copy);
}
static inline int security_sb_kern_mount (struct super_block *sb, void *data)
@@ -1988,7 +1990,8 @@
static inline void security_sb_free (struct super_block *sb)
{ }
-static inline int security_sb_copy_data (const char *fstype, void *orig, void *copy)
+static inline int security_sb_copy_data (struct file_system_type *type,
+ void *orig, void *copy)
{
return 0;
}
diff -urN -X dontdiff linux-2.6.3-mm4.o/security/dummy.c linux-2.6.3-mm4.w/security/dummy.c
--- linux-2.6.3-mm4.o/security/dummy.c 2004-02-25 22:42:16.000000000 -0500
+++ linux-2.6.3-mm4.w/security/dummy.c 2004-02-29 19:58:29.999348896 -0500
@@ -194,7 +194,8 @@
return;
}
-static int dummy_sb_copy_data (const char *fstype, void *orig, void *copy)
+static int dummy_sb_copy_data (struct file_system_type *type,
+ void *orig, void *copy)
{
return 0;
}
diff -urN -X dontdiff linux-2.6.3-mm4.o/security/selinux/hooks.c linux-2.6.3-mm4.w/security/selinux/hooks.c
--- linux-2.6.3-mm4.o/security/selinux/hooks.c 2004-02-25 22:42:16.000000000 -0500
+++ linux-2.6.3-mm4.w/security/selinux/hooks.c 2004-02-29 20:15:19.841829504 -0500
@@ -331,25 +331,24 @@
name = sb->s_type->name;
- /* Ignore these fileystems with binary mount option data. */
- if (!strcmp(name, "coda") ||
- !strcmp(name, "afs") || !strcmp(name, "smbfs"))
- goto out;
-
- /* NFS we understand. */
- if (!strcmp(name, "nfs")) {
- struct nfs_mount_data *d = data;
+ if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
- if (d->version < NFS_MOUNT_VERSION)
+ /* NFS we understand. */
+ if (!strcmp(name, "nfs")) {
+ struct nfs_mount_data *d = data;
+
+ if (d->version < NFS_MOUNT_VERSION)
+ goto out;
+
+ if (d->context[0]) {
+ context = d->context;
+ seen |= Opt_context;
+ }
+ } else
goto out;
- if (d->context[0]) {
- context = d->context;
- seen |= Opt_context;
- }
-
- /* Standard string-based options. */
} else {
+ /* Standard string-based options. */
char *p, *options = data;
while ((p = strsep(&options, ",")) != NULL) {
@@ -1886,7 +1885,7 @@
*to += len;
}
-static int selinux_sb_copy_data(const char *fstype, void *orig, void *copy)
+static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
{
int fnosec, fsec, rc = 0;
char *in_save, *in_curr, *in_end;
@@ -1896,8 +1895,7 @@
sec_curr = copy;
/* Binary mount data: just copy */
- if (!strcmp(fstype, "nfs") || !strcmp(fstype, "coda") ||
- !strcmp(fstype, "smbfs") || !strcmp(fstype, "afs")) {
+ if (type->fs_flags & FS_BINARY_MOUNTDATA) {
copy_page(sec_curr, in_curr);
goto out;
}
-
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