From nobody Fri Dec 19 14:48:29 2025 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) (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 7A32F1EE02F; Fri, 23 May 2025 11:46:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.198 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748000811; cv=none; b=K0q0eOxhhIfMND8Khi5kp3JhPZiH8bCAk9D92LYt+g5QSVTSpnZYCc65gfrLgX1BCHh7KduzB6SqB6KOm8H/VlZGIWlXODIxngUN1lPb6ibp+Y1MPpfUw2cV0Oi+0FdIKtsILUcoT+KN7y5svYF0+gxMU326TjSBhNg6W12LgAY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748000811; c=relaxed/simple; bh=41ZMNv9DZfWMf6Rr7Dfo1K3B4T7MWWsD7qyxjxJCH+M=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=JH3P5G0irCxNGWXVp+cBPP6Fv5i+VYJ1FLE/GjH3naUjXQwGvdd8J0ZwPWk0GFK3eA/fmalvB9LlEVrOi9asvhu5OXC/bR2vH8YsCxKIHnsQGp4IkPByhOGEltUOtERtmRh1hHUUOMB2zoWaLInkaGsWRLhcJw3t8/+EoNVT8m0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=gQ0QqYFn; arc=none smtp.client-ip=217.70.183.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="gQ0QqYFn" Received: by mail.gandi.net (Postfix) with ESMTPSA id 9C47C43295; Fri, 23 May 2025 11:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1748000801; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=mDq6MieyiMr43NuOWTLdL0EFY12TTvHhRagxM34k8EA=; b=gQ0QqYFnk9rZG9v1uNDabbudjF8lmrEkamaDERL3owhT5l1lEXeEeiDLkZWrTlZjIbdftK YhYFaRMlToVaQzQqLkKEUfVckqMZmXJWuyR2gSCCRBvDd1gMvCwD37tEPc0e6XogAOLzU8 4QhXenD1cL2qTdRj5oh1MenLyAen378EJQH7AHwYQFEvRTJaf5knDP8/kaWbbEfQM4qr6z 456/lDSLnd3+1/ukgP+eVu7UCXooOM76pde0n3pTLTtSSs5O8CV1bneZAGw7cq+BYN1B30 naK1UQZHYDz8AT596kQQDR5KZ3EA97lUifpSXFLqmJZtqtfSaU+3azD9v9/afw== From: =?utf-8?q?Alexis_Lothor=C3=A9?= Date: Fri, 23 May 2025 13:46:32 +0200 Subject: [PATCH] net: stmmac: add explicit check and error on invalid PTP clock rate Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250523-stmmac_tstamp_div-v1-1-bca8a5a3a477@bootlin.com> X-B4-Tracking: v=1; b=H4sIABdgMGgC/x3MQQqAIBBA0avErBN0wKCuEhFiY81CC0ciCO+et HyL/18QykwCU/dCppuFz9Rg+g784dJOirdmQI1WW0QlJUbn1yLFxWvd+FbBWmMw6EHjCK27MgV +/ue81PoBTtWoOGMAAAA= X-Change-ID: 20250522-stmmac_tstamp_div-f55112f06029 To: Alexandre Torgue , Jose Abreu , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Richard Cochran Cc: Thomas Petazzoni , Maxime Chevallier , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, =?utf-8?q?Alexis_Lothor=C3=A9?= X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddtgdekjeejucdltddurdegfedvrddttddmucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkvfevofesthekredtredtjeenucfhrhhomheptehlvgigihhsucfnohhthhhorhoruceorghlvgigihhsrdhlohhthhhorhgvsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeetudekvdffieehueeugfdujefgtddvgeekvddtieffffelvedtgeffjeekjeelgfenucffohhmrghinhepsghoohhtlhhinhdrtghomhenucfkphepvdgrtddvmeekgedvkeemfhelgegtmegvtddtmeemfhekheenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvrgdtvdemkeegvdekmehfleegtgemvgdttdemmehfkeehpdhhvghloheplgduledvrdduieekrddurdduleejngdpmhgrihhlfhhrohhmpegrlhgvgihishdrlhhothhhohhrvgessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepudeipdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqshhtmhefvdesshhtqdhmugdqmhgrihhlmhgrnhdrshhtohhrmhhrvghplhihrdgtohhmpdhrtghpthhtohepk hhusggrsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdgrrhhmqdhkvghrnhgvlheslhhishhtshdrihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopehthhhomhgrshdrphgvthgriiiiohhnihessghoohhtlhhinhdrtghomhdprhgtphhtthhopegrlhgvgihishdrlhhothhhohhrvgessghoohhtlhhinhdrtghomhdprhgtphhtthhopegrnhgurhgvfidonhgvthguvghvsehluhhnnhdrtghhpdhrtghpthhtohepmhgtohhquhgvlhhinhdrshhtmhefvdesghhmrghilhdrtghomh X-GND-Sasl: alexis.lothore@bootlin.com While some platforms implementing dwmac open-code the clk_ptp_rate value, some others dynamically retrieve the value at runtime. If the retrieved value happens to be 0 for any reason, it will eventually propagate up to PTP initialization when bringing up the interface, leading to a divide by 0: Division by zero in kernel. CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.30-00001-g48313bd576= 8a #22 Hardware name: STM32 (Device Tree Support) Call trace: unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x6c/0x8c dump_stack_lvl from Ldiv0_64+0x8/0x18 Ldiv0_64 from stmmac_init_tstamp_counter+0x190/0x1a4 stmmac_init_tstamp_counter from stmmac_hw_setup+0xc1c/0x111c stmmac_hw_setup from __stmmac_open+0x18c/0x434 __stmmac_open from stmmac_open+0x3c/0xbc stmmac_open from __dev_open+0xf4/0x1ac __dev_open from __dev_change_flags+0x1cc/0x224 __dev_change_flags from dev_change_flags+0x24/0x60 dev_change_flags from ip_auto_config+0x2e8/0x11a0 ip_auto_config from do_one_initcall+0x84/0x33c do_one_initcall from kernel_init_freeable+0x1b8/0x214 kernel_init_freeable from kernel_init+0x24/0x140 kernel_init from ret_from_fork+0x14/0x28 Exception stack(0xe0815fb0 to 0xe0815ff8) Prevent this division by 0 by adding an explicit check and error log about the actual issue. Signed-off-by: Alexis Lothor=C3=A9 Reviewed-by: Yanteng Si --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/ne= t/ethernet/stmicro/stmmac/stmmac_main.c index 918d7f2e8ba992208d7d6521a1e9dba01086058f..f68e3ece919cc88d0bf199a394b= c7e44b5dee095 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -835,6 +835,11 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *pri= v, u32 systime_flags) if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp)) return -EOPNOTSUPP; =20 + if (!priv->plat->clk_ptp_rate) { + netdev_err(priv->dev, "Invalid PTP clock rate"); + return -EINVAL; + } + stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags); priv->systime_flags =3D systime_flags; =20 --- base-commit: e0e2f78243385e7188a57fcfceb6a19f723f1dff change-id: 20250522-stmmac_tstamp_div-f55112f06029 Best regards, --=20 Alexis Lothor=C3=A9, Bootlin Embedded Linux and Kernel engineering https://bootlin.com