ovl: call secutiry hook in ovl_real_ioctl()

Verify LSM permissions for underlying file, since vfs_ioctl() doesn't do it. [Stephen Rothwell] export security_file_ioctl Signed-off-by: Miklos Szeredi <[email protected]>
ashr · Jun 3, 2020 · 292f902 · 292f902
1 parent 56230d9
commit 292f902
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diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
@@ -10,6 +10,7 @@
 #include <linux/uio.h>
 #include <linux/uaccess.h>
 #include <linux/splice.h>
+#include <linux/security.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include "overlayfs.h"
@@ -520,7 +521,9 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
 		return ret;
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	ret = vfs_ioctl(real.file, cmd, arg);
+	ret = security_file_ioctl(real.file, cmd, arg);
+	if (!ret)
+		ret = vfs_ioctl(real.file, cmd, arg);
 	revert_creds(old_cred);
 
 	fdput(real);

diff --git a/security/security.c b/security/security.c
@@ -1459,6 +1459,7 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	return call_int_hook(file_ioctl, 0, file, cmd, arg);
 }
+EXPORT_SYMBOL_GPL(security_file_ioctl);
 
 static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
 {
-Original file line number
+Diff line change
@@ Expand Up @@
     {
     	return call_int_hook(file_ioctl, 0, file, cmd, arg);
     }
+    EXPORT_SYMBOL_GPL(security_file_ioctl);
     static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
     {
@@ Expand Down @@