From: Colin Ian King Date: Sun, 28 Aug 2016 17:41:01 +0000 (+0100) Subject: i40e: avoid potential null pointer dereference when assigning len X-Git-Tag: v4.9.8~1241^2~79^2~4 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ff918912e1b8ba4e743d1f0b06ced1d01969e17c;p=platform%2Fkernel%2Flinux-rpi3.git i40e: avoid potential null pointer dereference when assigning len There is a sanitcy check for desc being null in the first line of function i40evf_debug_aq. However, before that, aq_desc is cast from desc, and aq_desc is being dereferenced on the assignment of len, so this could be a potential null pointer deference. Fix this by moving the initialization of len to the code block where len is being used and hence at this point we know it is OK to dereference aq_desc. Signed-off-by: Colin Ian King Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/i40evf/i40e_common.c b/drivers/net/ethernet/intel/i40evf/i40e_common.c index 4db0c03..7953c13 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_common.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_common.c @@ -302,7 +302,6 @@ void i40evf_debug_aq(struct i40e_hw *hw, enum i40e_debug_mask mask, void *desc, void *buffer, u16 buf_len) { struct i40e_aq_desc *aq_desc = (struct i40e_aq_desc *)desc; - u16 len = le16_to_cpu(aq_desc->datalen); u8 *buf = (u8 *)buffer; u16 i = 0; @@ -326,6 +325,8 @@ void i40evf_debug_aq(struct i40e_hw *hw, enum i40e_debug_mask mask, void *desc, le32_to_cpu(aq_desc->params.external.addr_low)); if ((buffer != NULL) && (aq_desc->datalen != 0)) { + u16 len = le16_to_cpu(aq_desc->datalen); + i40e_debug(hw, mask, "AQ CMD Buffer:\n"); if (buf_len < len) len = buf_len;