From: Jacob Keller <jacob.e.keller@intel.com>
Date: Wed, 12 Jul 2017 05:46:09 -0400
Subject: i40e: prevent snprintf format specifier truncation
Patch-mainline: v4.14-rc1
Git-commit: b5d5504aa1e961fc1f87ee7b092bf5ce1a7bf0de
References: bsc#1056658 FATE#322188 bsc#1056662 FATE#322186
Increase the size of the prefix buffer so that it can hold enough
characters for every possible input. Although 20 is enough for all
expected inputs, it is possible for the values to be larger than
expected, resulting in a possibly truncated string. Additionally, lets
use sizeof(prefix) in order to ensure we use the correct size if we need
to change the array length in the future.
New versions of GCC starting at 7 now include warnings to prevent
truncation unless you handle the return code. At most 27 bytes can be
written here, so lets just increase the buffer size even if for all
expected hw->bus.* values we only needed 20.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Benjamin Poirier <bpoirier@suse.com>
---
drivers/net/ethernet/intel/i40e/i40e_common.c | 4 ++--
drivers/net/ethernet/intel/i40evf/i40e_common.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/net/ethernet/intel/i40e/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_common.c
@@ -328,9 +328,9 @@ void i40e_debug_aq(struct i40e_hw *hw, e
len = buf_len;
/* write the full 16-byte chunks */
if (hw->debug_mask & mask) {
- char prefix[20];
+ char prefix[27];
- snprintf(prefix, 20,
+ snprintf(prefix, sizeof(prefix),
"i40e %02x:%02x.%x: \t0x",
hw->bus.bus_id,
hw->bus.device,
--- a/drivers/net/ethernet/intel/i40evf/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_common.c
@@ -333,9 +333,9 @@ void i40evf_debug_aq(struct i40e_hw *hw,
len = buf_len;
/* write the full 16-byte chunks */
if (hw->debug_mask & mask) {
- char prefix[20];
+ char prefix[27];
- snprintf(prefix, 20,
+ snprintf(prefix, sizeof(prefix),
"i40evf %02x:%02x.%x: \t0x",
hw->bus.bus_id,
hw->bus.device,