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authorEric Paris <eparis@redhat.com>2009-07-31 12:54:05 -0400
committerJames Morris <jmorris@namei.org>2009-08-06 09:02:21 +1000
commit84336d1a77ccd2c06a730ddd38e695c2324a7386 (patch)
tree9eeb414eff58e5b7165daa36c2ce3c2e7422632b /security
parent7c73875e7dda627040b12c19b01db634fa7f0fd1 (diff)
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SELinux: call cap_file_mmap in selinux_file_mmap
Currently SELinux does not check CAP_SYS_RAWIO in the file_mmap hook. This means there is no DAC check on the ability to mmap low addresses in the memory space. This function adds the DAC check for CAP_SYS_RAWIO while maintaining the selinux check on mmap_zero. This means that processes which need to mmap low memory will need CAP_SYS_RAWIO and mmap_zero but will NOT need the SELinux sys_rawio capability. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e65677da36b..8a78f584f46 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3034,9 +3034,21 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot,
int rc = 0;
u32 sid = current_sid();
- if (addr < mmap_min_addr)
+ /*
+ * notice that we are intentionally putting the SELinux check before
+ * the secondary cap_file_mmap check. This is such a likely attempt
+ * at bad behaviour/exploit that we always want to get the AVC, even
+ * if DAC would have also denied the operation.
+ */
+ if (addr < mmap_min_addr) {
rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
MEMPROTECT__MMAP_ZERO, NULL);
+ if (rc)
+ return rc;
+ }
+
+ /* do DAC check on address space usage */
+ rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
if (rc || addr_only)
return rc;