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authorEric Paris <eparis@redhat.com>2011-02-25 15:39:20 -0500
committerEric Paris <eparis@redhat.com>2011-02-25 15:40:00 -0500
commit0b24dcb7f2f7a0ce9b762eef0362c21c88f47b32 (patch)
tree9c7dc83e169cd4a2e5fd248e4b940f82131627b6 /security
parent47ac19ea429aee561f66e9cd05b908e8ffbc498a (diff)
Revert "selinux: simplify ioctl checking"
This reverts commit 242631c49d4cf39642741d6627750151b058233b. Conflicts: security/selinux/hooks.c SELinux used to recognize certain individual ioctls and check permissions based on the knowledge of the individual ioctl. In commit 242631c49d4cf396 the SELinux code stopped trying to understand individual ioctls and to instead looked at the ioctl access bits to determine in we should check read or write for that operation. This same suggestion was made to SMACK (and I believe copied into TOMOYO). But this suggestion is total rubbish. The ioctl access bits are actually the access requirements for the structure being passed into the ioctl, and are completely unrelated to the operation of the ioctl or the object the ioctl is being performed upon. Take FS_IOC_FIEMAP as an example. FS_IOC_FIEMAP is defined as: FS_IOC_FIEMAP _IOWR('f', 11, struct fiemap) So it has access bits R and W. What this really means is that the kernel is going to both read and write to the struct fiemap. It has nothing at all to do with the operations that this ioctl might perform on the file itself! Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c50
1 files changed, 42 insertions, 8 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8ffed9f2004e..8294dbfd1f16 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -24,9 +24,11 @@
*/
#include <linux/init.h>
+#include <linux/kd.h>
#include <linux/kernel.h>
#include <linux/tracehook.h>
#include <linux/errno.h>
+#include <linux/ext2_fs.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/xattr.h>
@@ -36,6 +38,7 @@
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
+#include <linux/proc_fs.h>
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
@@ -2849,16 +2852,47 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
const struct cred *cred = current_cred();
- u32 av = 0;
+ int error = 0;
- if (_IOC_DIR(cmd) & _IOC_WRITE)
- av |= FILE__WRITE;
- if (_IOC_DIR(cmd) & _IOC_READ)
- av |= FILE__READ;
- if (!av)
- av = FILE__IOCTL;
+ switch (cmd) {
+ case FIONREAD:
+ /* fall through */
+ case FIBMAP:
+ /* fall through */
+ case FIGETBSZ:
+ /* fall through */
+ case EXT2_IOC_GETFLAGS:
+ /* fall through */
+ case EXT2_IOC_GETVERSION:
+ error = file_has_perm(cred, file, FILE__GETATTR);
+ break;
+
+ case EXT2_IOC_SETFLAGS:
+ /* fall through */
+ case EXT2_IOC_SETVERSION:
+ error = file_has_perm(cred, file, FILE__SETATTR);
+ break;
- return file_has_perm(cred, file, av);
+ /* sys_ioctl() checks */
+ case FIONBIO:
+ /* fall through */
+ case FIOASYNC:
+ error = file_has_perm(cred, file, 0);
+ break;
+
+ case KDSKBENT:
+ case KDSKBSENT:
+ error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG,
+ SECURITY_CAP_AUDIT);
+ break;
+
+ /* default case assumes that the command will go
+ * to the file's ioctl() function.
+ */
+ default:
+ error = file_has_perm(cred, file, FILE__IOCTL);
+ }
+ return error;
}
static int default_noexec;

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