lib/mpi: fix off by one in mpi_read_raw_from_sgl

The patch fixes the analysis of the input data which contains an off by one. The issue is visible when the SGL contains one byte per SG entry. The code for checking for zero bytes does not operate on the data byte. Signed-off-by: Stephan Mueller <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
sfionov · Oct 20, 2015 · 63349d0 · 63349d0
1 parent 4a4b0ba
commit 63349d0
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
@@ -446,8 +446,11 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len)
 		const u8 *buff = sg_virt(sg);
 		int len = sg->length;
 
-		while (len-- && !*buff++)
+		while (len && !*buff) {
 			lzeros++;
+			len--;
+			buff++;
+		}
 
 		if (len && *buff)
 			break;