[4/6] switch readdir(2) to unsafe_copy_dirent_name()
diff mbox series

Message ID 20200528234919.4104604-1-viro@ZenIV.linux.org.uk
State New
Headers show
Series
  • [1/6] uaccess: Add user_read_access_begin/end and user_write_access_begin/end
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Commit Message

Al Viro May 28, 2020, 11:49 p.m. UTC
From: Al Viro <viro@zeniv.linux.org.uk>

... and the same for its compat counterpart

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/readdir.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

Patch
diff mbox series

diff --git a/fs/readdir.c b/fs/readdir.c
index ed6aaad451aa..a9085016a619 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -157,17 +157,18 @@  static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
 	}
 	buf->result++;
 	dirent = buf->dirent;
-	if (!access_ok(dirent,
+	if (!user_write_access_begin(dirent,
 			(unsigned long)(dirent->d_name + namlen + 1) -
 				(unsigned long)dirent))
 		goto efault;
-	if (	__put_user(d_ino, &dirent->d_ino) ||
-		__put_user(offset, &dirent->d_offset) ||
-		__put_user(namlen, &dirent->d_namlen) ||
-		__copy_to_user(dirent->d_name, name, namlen) ||
-		__put_user(0, dirent->d_name + namlen))
-		goto efault;
+	unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
+	unsafe_put_user(offset, &dirent->d_offset, efault_end);
+	unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
+	unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
+	user_write_access_end();
 	return 0;
+efault_end:
+	user_write_access_end();
 efault:
 	buf->result = -EFAULT;
 	return -EFAULT;
@@ -424,17 +425,18 @@  static int compat_fillonedir(struct dir_context *ctx, const char *name,
 	}
 	buf->result++;
 	dirent = buf->dirent;
-	if (!access_ok(dirent,
+	if (!user_write_access_begin(dirent,
 			(unsigned long)(dirent->d_name + namlen + 1) -
 				(unsigned long)dirent))
 		goto efault;
-	if (	__put_user(d_ino, &dirent->d_ino) ||
-		__put_user(offset, &dirent->d_offset) ||
-		__put_user(namlen, &dirent->d_namlen) ||
-		__copy_to_user(dirent->d_name, name, namlen) ||
-		__put_user(0, dirent->d_name + namlen))
-		goto efault;
+	unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
+	unsafe_put_user(offset, &dirent->d_offset, efault_end);
+	unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
+	unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
+	user_write_access_end();
 	return 0;
+efault_end:
+	user_write_access_end();
 efault:
 	buf->result = -EFAULT;
 	return -EFAULT;