From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.wp.pl (mx3.wp.pl [212.77.101.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 68E3119E982 for ; Thu, 12 Sep 2024 09:40:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.77.101.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726134010; cv=none; b=fjWqpr/g8gL2TWT5FUUAYmNeAgoJ6emGd9zdswX3JOSQr/U535dUUCoGY3cs+mG5alcs1ypUXuc960PxgSOZ3Sv9cYb/qnwVmluudWq8B3XREahGNnK4UI+ovy7BXRYYkzI3MfVKxtygmg0Yw/mhTpaJ6Qmxon9pEyduLShEn1U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726134010; c=relaxed/simple; bh=32A7mtoiTwrAP2CN+YkaC5Gp249jc9zREwQCABujAuM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ew40sazvrzgVLIbeEtI9lCws2B7ukqHykryG50Rs1jUggfcH9G7BigWgJphZZXQRHCS/Oc2i1dAJ9Ln8rUk54VzTB7ZJ3k4XMdz8cTkg7aWU2NfBRB5FkDTml/tgKNmZU+KBPMby/Ib2B0V+TJuB1Ehygwr/ObzAyigQQoKkqkc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=wp.pl; spf=pass smtp.mailfrom=wp.pl; dkim=pass (1024-bit key) header.d=wp.pl header.i=@wp.pl header.b=grONRflI; arc=none smtp.client-ip=212.77.101.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=wp.pl Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wp.pl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=wp.pl header.i=@wp.pl header.b="grONRflI" Received: (wp-smtpd smtp.wp.pl 43316 invoked from network); 12 Sep 2024 10:40:00 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wp.pl; s=1024a; t=1726130400; bh=NSNPO1OnVrFUBHbdGWrQyf3M9RLOSH9dTu1kXpgUHG8=; h=From:To:Cc:Subject; b=grONRflIHNi7WlEPJIEfbUnMC37qDrn5+3LYXZ1IjKXcsnsH2YWinKzzEKjrHLy6g n9SpnKgJBSO+/BXZJojmnxxVwTKUsaegcz8TCe9VKV8KtNu1rVMA2s/rSctStMnXKn zBBs2brgk8zHqrg83xZ3fU8UrfJughAGje3g7b28= Received: from 89-64-9-121.dynamic.chello.pl (HELO localhost) (stf_xl@wp.pl@[89.64.9.121]) (envelope-sender ) by smtp.wp.pl (WP-SMTPD) with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP for ; 12 Sep 2024 10:40:00 +0200 Date: Thu, 12 Sep 2024 10:39:59 +0200 From: Stanislaw Gruszka To: Ben Hutchings Cc: linux-wireless@vger.kernel.org, =?iso-8859-1?Q?Martin-=C9ric?= Racine , Brandon Nielsen Subject: Re: [PATCH] wifi: iwlegacy: Fix "field-spanning write" warning in il_enqueue_hcmd() Message-ID: <20240912083959.GA132706@wp.pl> References: Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-WP-MailID: 993568ca9aecb587a2ea8283de274a90 X-WP-AV: skaner antywirusowy Poczty Wirtualnej Polski X-WP-SPAM: NO 0000004 [QVdQ] On Thu, Sep 12, 2024 at 01:01:21AM +0200, Ben Hutchings wrote: > iwlegacy uses command buffers with a payload size of 320 > bytes (default) or 4092 bytes (huge). The struct il_device_cmd type > describes the default buffers and there is no separate type describing > the huge buffers. > > The il_enqueue_hcmd() function works with both default and huge > buffers, and has a memcpy() to the buffer payload. The size of > this copy may exceed 320 bytes when using a huge buffer, which > now results in a run-time warning: > > memcpy: detected field-spanning write (size 1014) of single field "&out_cmd->cmd.payload" at drivers/net/wireless/intel/iwlegacy/common.c:3170 (size 320) > > To fix this: > > - Define a new struct type for huge buffers, with a correctly sized > payload field > - When using a huge buffer in il_enqueue_hcmd(), cast the command > buffer pointer to that type when looking up the payload field > > Reported-by: Martin-Éric Racine > References: https://bugs.debian.org/1062421 > References: https://bugzilla.kernel.org/show_bug.cgi?id=219124 > Signed-off-by: Ben Hutchings > Fixes: 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()") > Tested-by: Martin-Éric Racine > Tested-by: Brandon Nielsen I proposed diffrent fix for this here: https://lore.kernel.org/linux-wireless/20240520073210.GA693073@wp.pl/ but never get feedback if it works on real HW. So I prefer this one, sice it was tested. Acked-by: Stanislaw Gruszka Martin-Éric and Brandon, could you plase also test patch from https://lore.kernel.org/linux-wireless/Zr2gxERA3RL3EwRe@elsanto/ if it does not break the driver? Thanks Stanislaw > --- > drivers/net/wireless/intel/iwlegacy/common.c | 13 ++++++++++++- > drivers/net/wireless/intel/iwlegacy/common.h | 12 ++++++++++++ > 2 files changed, 24 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c > index 9d33a66a49b5..4616293ec0cf 100644 > --- a/drivers/net/wireless/intel/iwlegacy/common.c > +++ b/drivers/net/wireless/intel/iwlegacy/common.c > @@ -3122,6 +3122,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) > struct il_cmd_meta *out_meta; > dma_addr_t phys_addr; > unsigned long flags; > + u8 *out_payload; > u32 idx; > u16 fix_size; > > @@ -3157,6 +3158,16 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) > out_cmd = txq->cmd[idx]; > out_meta = &txq->meta[idx]; > > + /* The payload is in the same place in regular and huge > + * command buffers, but we need to let the compiler know when > + * we're using a larger payload buffer to avoid "field- > + * spanning write" warnings at run-time for huge commands. > + */ > + if (cmd->flags & CMD_SIZE_HUGE) > + out_payload = ((struct il_device_cmd_huge *)out_cmd)->cmd.payload; > + else > + out_payload = out_cmd->cmd.payload; > + > if (WARN_ON(out_meta->flags & CMD_MAPPED)) { > spin_unlock_irqrestore(&il->hcmd_lock, flags); > return -ENOSPC; > @@ -3170,7 +3181,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) > out_meta->callback = cmd->callback; > > out_cmd->hdr.cmd = cmd->id; > - memcpy(&out_cmd->cmd.payload, cmd->data, cmd->len); > + memcpy(out_payload, cmd->data, cmd->len); > > /* At this point, the out_cmd now has all of the incoming cmd > * information */ > diff --git a/drivers/net/wireless/intel/iwlegacy/common.h b/drivers/net/wireless/intel/iwlegacy/common.h > index 69687fcf963f..027dae5619a3 100644 > --- a/drivers/net/wireless/intel/iwlegacy/common.h > +++ b/drivers/net/wireless/intel/iwlegacy/common.h > @@ -560,6 +560,18 @@ struct il_device_cmd { > > #define TFD_MAX_PAYLOAD_SIZE (sizeof(struct il_device_cmd)) > > +/** > + * struct il_device_cmd_huge > + * > + * For use when sending huge commands. > + */ > +struct il_device_cmd_huge { > + struct il_cmd_header hdr; /* uCode API */ > + union { > + u8 payload[IL_MAX_CMD_SIZE - sizeof(struct il_cmd_header)]; > + } __packed cmd; > +} __packed; > + > struct il_host_cmd { > const void *data; > unsigned long reply_page;