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authorAl Viro <viro@zeniv.linux.org.uk>2012-05-30 17:11:23 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-06-01 10:37:01 -0400
commit8b3ec6814c83d76b85bd13badc48552836c24839 (patch)
tree2430a4511c7ea41f67b0d841f4c42eac43828db3 /security/security.c
parente5467859f7f79b69fc49004403009dfdba3bec53 (diff)
downloadlinux-8b3ec6814c83d76b85bd13badc48552836c24839.tar.gz
take security_mmap_file() outside of ->mmap_sem
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'security/security.c')
-rw-r--r--security/security.c33
1 files changed, 30 insertions, 3 deletions
diff --git a/security/security.c b/security/security.c
index d91c66d3956..3b11b3b72fe 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
@@ -657,11 +660,35 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return security_ops->file_ioctl(file, cmd, arg);
}
-int security_mmap_file(struct file *file, unsigned long reqprot,
- unsigned long prot, unsigned long flags)
+int security_mmap_file(struct file *file, unsigned long prot,
+ unsigned long flags)
{
+ unsigned long reqprot = prot;
int ret;
-
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC?
+ *
+ * (the exception is when the underlying filesystem is noexec
+ * mounted, in which case we dont add PROT_EXEC.)
+ */
+ if (!(reqprot & PROT_READ))
+ goto out;
+ if (!(current->personality & READ_IMPLIES_EXEC))
+ goto out;
+ if (!file) {
+ prot |= PROT_EXEC;
+ } else 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))
+ goto out;
+#endif
+ prot |= PROT_EXEC;
+ }
+out:
ret = security_ops->mmap_file(file, reqprot, prot, flags);
if (ret)
return ret;