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-rw-r--r--security/security.c51
1 files changed, 46 insertions, 5 deletions
diff --git a/security/security.c b/security/security.c
index 5497a57fba01..3efc9b12aef4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -20,6 +20,9 @@
#include <linux/ima.h>
#include <linux/evm.h>
#include <linux/fsnotify.h>
+#include <linux/mman.h>
+#include <linux/mount.h>
+#include <linux/personality.h>
#include <net/flow.h>
#define MAX_LSM_EVM_XATTR 2
@@ -657,18 +660,56 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return security_ops->file_ioctl(file, cmd, arg);
}
-int security_file_mmap(struct file *file, unsigned long reqprot,
- unsigned long prot, unsigned long flags,
- unsigned long addr, unsigned long addr_only)
+static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
{
- int ret;
+ /*
+ * Does we have PROT_READ and does the application expect
+ * it to imply PROT_EXEC? If not, nothing to talk about...
+ */
+ if ((prot & (PROT_READ | PROT_EXEC)) != PROT_READ)
+ return prot;
+ if (!(current->personality & READ_IMPLIES_EXEC))
+ return prot;
+ /*
+ * if that's an anonymous mapping, let it.
+ */
+ if (!file)
+ return prot | PROT_EXEC;
+ /*
+ * ditto if it's not on noexec mount, except that on !MMU we need
+ * BDI_CAP_EXEC_MMAP (== VM_MAYEXEC) in this case
+ */
+ if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) {
+#ifndef CONFIG_MMU
+ unsigned long caps = 0;
+ struct address_space *mapping = file->f_mapping;
+ if (mapping && mapping->backing_dev_info)
+ caps = mapping->backing_dev_info->capabilities;
+ if (!(caps & BDI_CAP_EXEC_MAP))
+ return prot;
+#endif
+ return prot | PROT_EXEC;
+ }
+ /* anything on noexec mount won't get PROT_EXEC */
+ return prot;
+}
- ret = security_ops->file_mmap(file, reqprot, prot, flags, addr, addr_only);
+int security_mmap_file(struct file *file, unsigned long prot,
+ unsigned long flags)
+{
+ int ret;
+ ret = security_ops->mmap_file(file, prot,
+ mmap_prot(file, prot), flags);
if (ret)
return ret;
return ima_file_mmap(file, prot);
}
+int security_mmap_addr(unsigned long addr)
+{
+ return security_ops->mmap_addr(addr);
+}
+
int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
unsigned long prot)
{