fs/xattr.c:getxattr(): improve handling of allocation failures

This allocation can be as large as 64k.

 - Add __GFP_NOWARN so the falied kmalloc() is silent

 - Fall back to vmalloc() if the kmalloc() failed

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 4 deletions

diff --git a/fs/xattr.c b/fs/xattr.c
index 1d7ac3790458..4d45b7189e7e 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -427,6 +427,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
 {
         ssize_t error;
         void *kvalue = NULL;
+        void *vvalue = NULL;
         char kname[XATTR_NAME_MAX + 1];
 
         error = strncpy_from_user(kname, name, sizeof(kname));
@@ -438,9 +439,13 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
         if (size) {
                 if (size > XATTR_SIZE_MAX)
                         size = XATTR_SIZE_MAX;
-                kvalue = kzalloc(size, GFP_KERNEL);
-                if (!kvalue)
-                        return -ENOMEM;
+                kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
+                if (!kvalue) {
+                        vvalue = vmalloc(size);
+                        if (!vvalue)
+                                return -ENOMEM;
+                        kvalue = vvalue;
+                }
         }
 
         error = vfs_getxattr(d, kname, kvalue, size);
@@ -452,7 +457,10 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
                    than XATTR_SIZE_MAX bytes. Not possible. */
                 error = -E2BIG;
         }
-        kfree(kvalue);
+        if (vvalue)
+                vfree(vvalue);
+        else
+                kfree(kvalue);
         return error;
 }