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[PATCH] xfsrestore: fix string corruption in shrink()

To: xfs@xxxxxxxxxxx
Subject: [PATCH] xfsrestore: fix string corruption in shrink()
From: Mark Tinguely <tinguely@xxxxxxx>
Date: Thu, 13 Nov 2014 13:14:45 -0600
Delivered-to: xfs@xxxxxxxxxxx
User-agent: quilt/0.51-1
Linux strcpy() corrupts the output string when the input
and output strings overlap. The shrink() function in xfsrestore
uses an overlapping strcpy() to remove special characters when
processing an interactive command line. The resultant command
will fail.

examples:
 -> cd "AOGC exome chip core genotyping"
AOGC exome chp  core genotyping not found
 -> cd "t t"
tt not found

Fix my manually moving the characters in the array.

Signed-off-by: Mark Tinguely <tinguely@xxxxxxx>
---
 restore/tree.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

Index: b/restore/tree.c
===================================================================
--- a/restore/tree.c
+++ b/restore/tree.c
@@ -4857,7 +4857,19 @@ distance_to_space( char *s, char *l )
 static void
 shrink( char *s, size_t cnt )
 {
-       strcpy( s, s + cnt );
+       /*
+        * Linux strcpy corrupts the string if the src and dst overlap.
+        * Manually copy the entries to the left.
+        *
+        * Since the liter array is mostly nulls, shrink is not moving
+        * the array left as intended. Does not seem to be many embedded
+        * processing characters, so leaving it for now
+        */
+       char *m = s + cnt;
+       while (*m != '\0')
+               *s++ = *m++;
+       /* NULL the last character of the string */
+       *s = '\0';
 }
 
 static int


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