--- /dev/null
+From 58a898cb4459055bb488ca815c23b880c242a27d Mon Sep 17 00:00:00 2001
+From: Even Rouault <even.rouault@spatialys.com>
+Date: Sat, 12 May 2018 15:32:31 +0200
+Subject: [PATCH] LZWDecodeCompat(): fix potential index-out-of-bounds write.
+ Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2780 /
+ CVE-2018-8905
+
+The fix consists in using the similar code LZWDecode() to validate we
+don't write outside of the output buffer.
+
+---
+CVE: CVE-2018-8905
+
+Upstream-Status: Backport [gitlab.com/libtiff/libtiff/commit/58a898...]
+
+Signed-off-by: Joe Slater <joe.slater@windriver.com>
+
+---
+ libtiff/tif_lzw.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/libtiff/tif_lzw.c b/libtiff/tif_lzw.c
+index 4ccb443..94d85e3 100644
+--- a/libtiff/tif_lzw.c
++++ b/libtiff/tif_lzw.c
+@@ -602,6 +602,7 @@ LZWDecodeCompat(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
+ char *tp;
+ unsigned char *bp;
+ int code, nbits;
++ int len;
+ long nextbits, nextdata, nbitsmask;
+ code_t *codep, *free_entp, *maxcodep, *oldcodep;
+
+@@ -753,13 +754,18 @@ LZWDecodeCompat(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
+ } while (--occ);
+ break;
+ }
+- assert(occ >= codep->length);
+- op += codep->length;
+- occ -= codep->length;
+- tp = op;
++ len = codep->length;
++ tp = op + len;
+ do {
+- *--tp = codep->value;
+- } while( (codep = codep->next) != NULL );
++ int t;
++ --tp;
++ t = codep->value;
++ codep = codep->next;
++ *tp = (char)t;
++ } while (codep && tp > op);
++ assert(occ >= len);
++ op += len;
++ occ -= len;
+ } else {
+ *op++ = (char)code;
+ occ--;
+--
+1.7.9.5
+
