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authorLorenzo Hernández García-Hierro <lorenzo@gnu.org>2005-06-25 14:54:35 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-25 16:24:26 -0700
commit09ffd94fb15d85fbf9eebb8180f50264b264d6fe (patch)
tree688a5b60f9718a56a5d4386ef10596e77fb65b7b /security
parent6b9921976f0861e04828b3aff66696c1f3fd900d (diff)
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[PATCH] selinux: add executable heap check
This patch,based on sample code by Roland McGrath, adds an execheap permission check that controls the ability to make the heap executable so that this can be prevented in almost all cases (the X server is presently an exception, but this will hopefully be resolved in the future) so that even programs with execmem permission will need to have the anonymous memory mapped in order to make it executable. The only reason that we use a permission check for such restriction (vs. making it unconditional) is that the X module loader presently needs it; it could possibly be made unconditional in the future when X is changed. The policy patch for the execheap permission is available at: http://pearls.tuxedo-es.org/patches/selinux/policy-execheap.patch Signed-off-by: Lorenzo Hernandez Garcia-Hierro <lorenzo@gnu.org> Acked-by: James Morris <jmorris@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c11
-rw-r--r--security/selinux/include/av_perm_to_string.h1
-rw-r--r--security/selinux/include/av_permissions.h1
3 files changed, 13 insertions, 0 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ad725213f56..932eef18db3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2477,6 +2477,17 @@ static int selinux_file_mprotect(struct vm_area_struct *vma,
prot = reqprot;
#ifndef CONFIG_PPC32
+ if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXECUTABLE) &&
+ (vma->vm_start >= vma->vm_mm->start_brk &&
+ vma->vm_end <= vma->vm_mm->brk)) {
+ /*
+ * We are making an executable mapping in the brk region.
+ * This has an additional execheap check.
+ */
+ rc = task_has_perm(current, current, PROCESS__EXECHEAP);
+ if (rc)
+ return rc;
+ }
if (vma->vm_file != NULL && vma->anon_vma != NULL && (prot & PROT_EXEC)) {
/*
* We are making executable a file mapping that has
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index e81f0226c37..1deb59e1b76 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -71,6 +71,7 @@
S_(SECCLASS_PROCESS, PROCESS__SETCURRENT, "setcurrent")
S_(SECCLASS_PROCESS, PROCESS__EXECMEM, "execmem")
S_(SECCLASS_PROCESS, PROCESS__EXECSTACK, "execstack")
+ S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap")
S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue")
S_(SECCLASS_MSG, MSG__SEND, "send")
S_(SECCLASS_MSG, MSG__RECEIVE, "receive")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index 38ce18b3328..a78b5d59c9f 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -466,6 +466,7 @@
#define PROCESS__SETCURRENT 0x01000000UL
#define PROCESS__EXECMEM 0x02000000UL
#define PROCESS__EXECSTACK 0x04000000UL
+#define PROCESS__EXECHEAP 0x08000000UL
#define IPC__CREATE 0x00000001UL
#define IPC__DESTROY 0x00000002UL