[PATCH 1/1] NTFS: Fix a potential DoS by rate limiting printk().

[Anton Altaparmakov]

This is patch 1/1 in the series.  It contains the following ChangeSet:

<aia21@xxxxxxxxxx> (05/01/25 1.1983.6.1)
   NTFS: Add printk rate limiting for ntfs_warning() and ntfs_error() when
         compiled without debug.  This avoids a possible denial of service
         attack.  Thanks to Carl-Daniel Hailfinger from SuSE for pointing this
         out.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

===================================================================

diff -Nru a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
--- a/fs/ntfs/ChangeLog	2005-01-25 10:50:37 +00:00
+++ b/fs/ntfs/ChangeLog	2005-01-25 10:50:37 +00:00
@@ -25,6 +25,13 @@
 	- Enable the code for setting the NT4 compatibility flag when we start
 	  making NTFS 1.2 specific modifications.
 
+2.1.23-WIP
+
+	- Add printk rate limiting for ntfs_warning() and ntfs_error() when
+	  compiled without debug.  This avoids a possible denial of service
+	  attack.  Thanks to Carl-Daniel Hailfinger from SuSE for pointing this
+	  out.
+
 2.1.22 - Many bug and race fixes and error handling improvements.
 
 	- Improve error handling in fs/ntfs/inode.c::ntfs_truncate().
diff -Nru a/fs/ntfs/debug.c b/fs/ntfs/debug.c
--- a/fs/ntfs/debug.c	2005-01-25 10:50:37 +00:00
+++ b/fs/ntfs/debug.c	2005-01-25 10:50:37 +00:00
@@ -53,6 +53,10 @@
 	va_list args;
 	int flen = 0;
 
+#ifndef DEBUG
+	if (!printk_ratelimit())
+		return;
+#endif
 	if (function)
 		flen = strlen(function);
 	spin_lock(&err_buf_lock);
@@ -93,6 +97,10 @@
 	va_list args;
 	int flen = 0;
 
+#ifndef DEBUG
+	if (!printk_ratelimit())
+		return;
+#endif
 	if (function)
 		flen = strlen(function);
 	spin_lock(&err_buf_lock);
-
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