-----Original Message----- From: Pavel Machek pavel@denx.de Sent: Thursday, November 21, 2019 2:35 AM To: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org; stable@vger.kernel.org; Williams, Mitch A mitch.a.williams@intel.com; Bowers, AndrewX andrewx.bowers@intel.com; Kirsher, Jeffrey T jeffrey.t.kirsher@intel.com; Sasha Levin sashal@kernel.org Subject: Re: [PATCH 4.19 079/422] i40e: use correct length for strncpy
Hi!
From: Mitch Williams mitch.a.williams@intel.com
[ Upstream commit 7eb74ff891b4e94b8bac48f648a21e4b94ddee64 ]
Caught by GCC 8. When we provide a length for strncpy, we should not include the terminating null. So we must tell it one less than the size of the destination buffer.
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c @@ -694,7 +694,8 @@ static long i40e_ptp_create_clock(struct i40e_pf *pf) if (!IS_ERR_OR_NULL(pf->ptp_clock)) return 0;
- strncpy(pf->ptp_caps.name, i40e_driver_name, sizeof(pf->ptp_caps.name));
- strncpy(pf->ptp_caps.name, i40e_driver_name,
sizeof(pf->ptp_caps.name) - 1);So... pf is allocated with kzalloc, which will provide the null termination... so the code is okay.
On the other hand, the = 0 below is unneeded by the same logic, so this is a bit confusing.
Best regards, Pavel
Thanks for catching this, Pavel. Aleksandr Loktionov owns this driver now. He can get this taken care of. -Mitch
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