1 files changed, 5 insertions, 1 deletions

diff --git a/archival/libarchive/decompress_unlzma.c b/archival/libarchive/decompress_unlzma.c
index a9040877e..be4342414 100644
--- a/archival/libarchive/decompress_unlzma.c
+++ b/archival/libarchive/decompress_unlzma.c
@@ -450,8 +450,12 @@ unpack_lzma_stream(transformer_state_t *xstate)
  IF_NOT_FEATURE_LZMA_FAST(string:)
                         do {
                                 uint32_t pos = buffer_pos - rep0;
-                                if ((int32_t)pos < 0)
+                                if ((int32_t)pos < 0) {
                                         pos += header.dict_size;
+                                        /* bug 10436 has an example file where this triggers: */
+                                        if ((int32_t)pos < 0)
+                                                goto bad;
+                                }
                                 previous_byte = buffer[pos];
  IF_NOT_FEATURE_LZMA_FAST(one_byte2:)
                                 buffer[buffer_pos++] = previous_byte;