From: Jacob Keller Date: Wed, 12 Jul 2017 09:46:09 +0000 (-0400) Subject: i40e: prevent snprintf format specifier truncation X-Git-Tag: v4.1.12-117.0_27200813_3~219 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=46694d324a628c39f2af2dc17d782c4fd582d872;p=users%2Fjedix%2Flinux-maple.git i40e: prevent snprintf format specifier truncation 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 Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher Orabug: 26785018 (cherry picked from commit b5d5504aa1e961fc1f87ee7b092bf5ce1a7bf0de) Signed-off-by: Jack Vogel Reviewed-by: Kyle Fortin --- diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c b/drivers/net/ethernet/intel/i40e/i40e_common.c index c052c913a254..5e053b948a90 100644 --- 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, enum i40e_debug_mask mask, void *desc, 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, diff --git a/drivers/net/ethernet/intel/i40evf/i40e_common.c b/drivers/net/ethernet/intel/i40evf/i40e_common.c index bcaf4a690403..0a9a54b5515c 100644 --- 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, enum i40e_debug_mask mask, void *desc, 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,