Subject: [PATCH] qlge: Avoid reading past end of buffer

From: Kees Cook <[email-masked]>
Date: Fri, 5 May 2017 15:34:34 -0700

Using memcpy() from a string that is shorter than the length copied means
the destination buffer is being filled with arbitrary data from the kernel
rodata segment. Instead, use strncpy() which will fill the trailing bytes
with zeros.

This was found with the future CONFIG_FORTIFY_SOURCE feature.

Cc: Daniel Micay <[email-masked]>
Signed-off-by: Kees Cook <[email-masked]>
---
 drivers/net/ethernet/qlogic/qlge/qlge_dbg.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c b/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c
index 829be21f97b2..28ea0af89aef 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c
@@ -765,7 +765,7 @@ int ql_core_dump(struct ql_adapter *qdev, struct ql_mpi_coredump *mpi_coredump)
 		sizeof(struct mpi_coredump_global_header);
 	mpi_coredump->mpi_global_header.imageSize =
 		sizeof(struct ql_mpi_coredump);
-	memcpy(mpi_coredump->mpi_global_header.idString, "MPI Coredump",
+	strncpy(mpi_coredump->mpi_global_header.idString, "MPI Coredump",
 		sizeof(mpi_coredump->mpi_global_header.idString));
 
 	/* Get generic NIC reg dump */
@@ -1255,7 +1255,7 @@ static void ql_gen_reg_dump(struct ql_adapter *qdev,
 		sizeof(struct mpi_coredump_global_header);
 	mpi_coredump->mpi_global_header.imageSize =
 		sizeof(struct ql_reg_dump);
-	memcpy(mpi_coredump->mpi_global_header.idString, "MPI Coredump",
+	strncpy(mpi_coredump->mpi_global_header.idString, "MPI Coredump",
 		sizeof(mpi_coredump->mpi_global_header.idString));

-- 
2.7.4

-- 
Kees Cook
Pixel Security