[PATCH 4.9 015/310] qlge: Avoid reading past end of buffer

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@xxxxxxxxxxxx>


[ Upstream commit df5303a8aa9a0a6934f4cea7427f1edf771f21c2 ]

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 <danielmicay@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/qlogic/qlge/qlge_dbg.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- 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
 		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_ad
 		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));