take security_mmap_file() outside of ->mmap_sem

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 24 insertions, 21 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 49283da..34b280f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -979,7 +979,6 @@ static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 	struct inode *inode;
 	vm_flags_t vm_flags;
 	int error;
-	unsigned long reqprot = prot;
 
 	/*
 	 * Does the application expect PROT_READ to imply PROT_EXEC?
@@ -1105,10 +1104,6 @@ static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 	if (error)
 		return error;
 
-	error = security_mmap_file(file, reqprot, prot, flags);
-	if (error)
-		return error;
-
 	return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
 
@@ -1130,9 +1125,12 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 	unsigned long ret;
 	struct mm_struct *mm = current->mm;
 
-	down_write(&mm->mmap_sem);
-	ret = do_mmap(file, addr, len, prot, flag, offset);
-	up_write(&mm->mmap_sem);
+	ret = security_mmap_file(file, prot, flag);
+	if (!ret) {
+		down_write(&mm->mmap_sem);
+		ret = do_mmap(file, addr, len, prot, flag, offset);
+		up_write(&mm->mmap_sem);
+	}
 	return ret;
 }
 EXPORT_SYMBOL(vm_mmap);
@@ -1168,9 +1166,12 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
 
 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 
-	down_write(&current->mm->mmap_sem);
-	retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	up_write(&current->mm->mmap_sem);
+	retval = security_mmap_file(file, prot, flags);
+	if (!retval) {
+		down_write(&current->mm->mmap_sem);
+		retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+		up_write(&current->mm->mmap_sem);
+	}
 
 	if (file)
 		fput(file);
diff --git a/mm/nommu.c b/mm/nommu.c
index acfe419..8cbfd62 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -889,7 +889,6 @@ static int validate_mmap_request(struct file *file,
 				 unsigned long *_capabilities)
 {
 	unsigned long capabilities, rlen;
-	unsigned long reqprot = prot;
 	int ret;
 
 	/* do the simple checks first */
@@ -1050,9 +1049,6 @@ static int validate_mmap_request(struct file *file,
 	ret = security_mmap_addr(addr);
 	if (ret < 0)
 		return ret;
-	ret = security_mmap_file(file, reqprot, prot, flags);
-	if (ret < 0)
-		return ret;
 
 	/* looks okay */
 	*_capabilities = capabilities;
@@ -1492,9 +1488,12 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 	unsigned long ret;
 	struct mm_struct *mm = current->mm;
 
-	down_write(&mm->mmap_sem);
-	ret = do_mmap(file, addr, len, prot, flag, offset);
-	up_write(&mm->mmap_sem);
+	ret = security_mmap_file(file, prot, flag);
+	if (!ret) {
+		down_write(&mm->mmap_sem);
+		ret = do_mmap(file, addr, len, prot, flag, offset);
+		up_write(&mm->mmap_sem);
+	}
 	return ret;
 }
 EXPORT_SYMBOL(vm_mmap);
@@ -1515,9 +1514,12 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
 
 	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 
-	down_write(&current->mm->mmap_sem);
-	retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	up_write(&current->mm->mmap_sem);
+	ret = security_mmap_file(file, prot, flags);
+	if (!ret) {
+		down_write(&current->mm->mmap_sem);
+		retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+		up_write(&current->mm->mmap_sem);
+	}
 
 	if (file)
 		fput(file);