From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 D5418362154 for ; Thu, 23 Jul 2026 16:40:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784824818; cv=none; b=KnY/91WzJ/NlsYlg8kLtrzjlrBhrrrGMCYgGhLaBIsNgblshOG/NqHi7cHOIRi0A5LoZYs7YsjS2M+Pq3FnhI/1ooSX/uFtTRw5EpPTino2+vmNWXPHv4/xeKKihN82CKbkzibJrlp6bHPEOVSFIMBJSInPocmSTcarIHuaPlog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784824818; c=relaxed/simple; bh=89xsqU4N/16DllPbCM+QgiZcRJvl/c4DSF46VkWkHuI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TukS1l1/pH3SAg0f2r4h1/UZ2UNfuNAo6ttJx2mMcil/JyoL+iSAVhHGzyZCedHoMcpxlx7J9piS+rpZNVIt9evLEGyVBPoIMJmAYB4DE3r3LQRwXqtZhHxrJE3W/QQkC1OjyJcCjkGJdsoJiVE95Ba0O+rNjgcgk4TzxjsHrD8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=cWCI7S9z; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=BZ+PokBv; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="cWCI7S9z"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="BZ+PokBv" Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 66NCvSJc154398 for ; Thu, 23 Jul 2026 16:40:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= lk89yAHBTKggkrt0bGV2u4rtt4D0N+23FXFRfMG2ZEQ=; b=cWCI7S9zt7D3hu+q C+H0WcoEH6uvbsZ6BV6RyI7kjtUV4ajDxRWoV09mVQow+M2zxc/wxGJLzjcajsoQ Hwo4caCngxPV/ftgpHO2i4Qws0iO6hmM4S7n7xpWR4XaI/qAeNFDldpnOHd/W2d4 r/W2BNfbHq3wrOID3Gx8ka4msjaY41vpd7PaaSCIuI17+ayzpRmp2nokyUxleZiw XoUz7Kq6MHgTcnlW5tNHMt8sE/3zX+8Y5KTS3w9oB4CoZrOESeqeJLTwb51wsK88 KvGh/cDh7iI1wL0aDKLH+LNYxkpE5MgxyKR9SfcG7tjslmGiKYa4szlCg/xV5QW2 hSvIXA== Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4fk7b541us-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Thu, 23 Jul 2026 16:40:13 +0000 (GMT) Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-38e6d253330so750778a91.1 for ; Thu, 23 Jul 2026 09:40:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1784824812; x=1785429612; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=lk89yAHBTKggkrt0bGV2u4rtt4D0N+23FXFRfMG2ZEQ=; b=BZ+PokBvaJnrPtSu9xcJ3H7WWFWt2DFgdVd4rkjQ96JjsK31VnsJ7T0wrU2XG+pAmN Zd7nP3UJFcDEtxrO3PZir1ktes7fD4AViemUQA8OYQ9JeJy0hvqEmdxOUGh+8GbenAHX HPpgaeRQ16gCuKpguLUek4aX+Wxizo8YcefOJlEftwZyyGgdH3fYORIs0/Xxysb0BgyA tO1ZfuGLfkAmzZNwciWZLusTlHjZtyV+5K1t8SZdLpQcrNaX1InO+vSAg7Dw4yKqE79F WBT/EzYhb+ZHTzq2DU7b5KQErYLN+onq0Lkd9/tIzG1vKEgpvARMTQUufkYyBuhg7pEs JnXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784824812; x=1785429612; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=lk89yAHBTKggkrt0bGV2u4rtt4D0N+23FXFRfMG2ZEQ=; b=aSrNsK8WHeDaGA3UdKfyP79cea/VJwUoX71a+zX9I5YrvxB5eiI1LTL0V+HcbeGbtj luxZ1hPGaKgc4PyP7SXmHBLYYud8thTq9rVsDuetRO/DeO8YkXddQ03ooD6CqhNhJyO/ pzuRIoaTUaSUX+4K5zzwWFAOHRa7dGs/0ezdb7raK/67SJhX8v9Xtdgo7rTLPGb3RFsG NOCiATf5v7Cf9g8vkD4bVL0pK9O7/314jQLamIyEsjEJDUD4SHJ7ZKvNwhRKyfiy2rHE 8plX6M5daU8QMtq++WvTGIok+eZBX3LMPsSpU8NDZVgf3evYqeco9eIGv4y+ok25DnMY XnAA== X-Forwarded-Encrypted: i=1; AHgh+Rql++W/0XJUUiYH4F75yWIr/i22grMCXasPcAWCFNfU7N0/TVj99nxj/k8n0GVlVAcacD46SufU7dDwuLc=@vger.kernel.org X-Gm-Message-State: AOJu0Yy5CMacVB9MVbfYEjtOeBfK9H6xhoG2Zo9Yh+wuuMsRXCw3dMMM t3wpgnusFj+YIdCMNm2wqK+JEAtr0O+8RfpivuXU1rXTNt29x+GQMtgKif+bGVtIEhLTZW0csAp vT9aZijfFKEPB0pczA8/cxyPS3GEHAoILkVv0OWPzIM8tuJUlojIwXXqm8FLoYOTzhoM= X-Gm-Gg: AR+sD10y8v6Jm+rcqo+DtBQk02xJ8gZP5c+OdThjWNAzcyeS6iOkQ8GAu8oQq/N0UQd xzno7R6ZH3G2iNAmSqZbFcHYJlBuiRJdrfvn56QS2jPGddEZFarGdUkHoRieF7pFFPjtRW7ZtFU OMzGwS4yFYNFhRv087cxzs/ugBRFeCHC+ah5itQufG+YAqyoE85q7BQEUQbU8TbXw7e60E/eg97 SRKcr+6mX3omruOGRTM7lzqGS+htHIbPhDE0Sog5imIekrHGJ12QDONpmX+jD/F95iPZe5mLilx VUBiuufE+TK+ePBUVFgvqV36isfUfR+yd8guRA5vmsPywiO8YojMNYPe4LvhKH0kphgo4kk+3c0 Lkw0cxc8zevWVku7iUPjdiWKShicRVm+V X-Received: by 2002:a17:90b:2e46:b0:38e:7297:a92e with SMTP id 98e67ed59e1d1-38ec841fd7emr3114809a91.9.1784824812484; Thu, 23 Jul 2026 09:40:12 -0700 (PDT) X-Received: by 2002:a17:90b:2e46:b0:38e:7297:a92e with SMTP id 98e67ed59e1d1-38ec841fd7emr3114762a91.9.1784824811728; Thu, 23 Jul 2026 09:40:11 -0700 (PDT) Received: from [192.168.0.5] ([49.204.109.252]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-13d130f55c6sm28488722c88.15.2026.07.23.09.40.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Jul 2026 09:40:11 -0700 (PDT) Message-ID: Date: Thu, 23 Jul 2026 22:10:06 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] clk: Guard clk_round_rate() against error pointers To: Brian Masney Cc: bjorn.andersson@oss.qualcomm.com, Michael Turquette , Stephen Boyd , konrad.dybcio@oss.qualcomm.com, mukesh.savaliya@oss.qualcomm.com, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, chandana.chiluveru@oss.qualcomm.com References: <20260723-fix_ptr_check_on_clk-v1-1-568a7ed87746@oss.qualcomm.com> Content-Language: en-US From: Praveen Talari In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzIzMDE2MyBTYWx0ZWRfXzwTXLebr0s90 cZJn42TBUzIiQMb5QxXn+OVp1X2AZ6tX+c95n/bi+ZRyBx0Mu4u705GH/523/vHoMdnryu3V7nD iTaPAHIOtQl6HQBIVmEw0NgBrwvjkKuUQmFBEUDjZo4HOq2g0iAn0jDzI3iWhJJ8Ya/bxVIbVYW t16i6BQASwpUfjqyIi7U8cL7fOerst4dU7uum4hajcYzSbw1axpYchs4uJu3YKoQIpBUKMuWhX7 c1QsiZ3+qs1YPOvlODUsC6fjyNbbGKP/r8t1SRw71e5or6hWWjvCgXVFmLSw3UveinzGKGehz5d yT30zr0XG67SgJsIe2JQjHNBLtIEjK9ZEeiYAL6aKY3zccRc2uKGz+3RbrHpG0KFqFGNYz+k1eG bt4/QEPl0Og+4xDHg6ALlWH3OEZsntZ3oJ6k4al7F3XoSdW/YoFfbM3nLrW/vkX11T+HuPrfNVP CM9W59BfAMDssIJEJ7Q== X-Proofpoint-GUID: cFXEsJlBMZBTaDC48X8z4ONw0AbIBLwq X-Proofpoint-Spam-Info: AW1haW4tMjYwNzIzMDE2MyBTYWx0ZWRfXwgZ0/HT8Z29e VeQhdSC60dNrEePkmZsyMy6ryW2kwsT0ihiW3aPi2o4iSg4JNzMfKBaR5vRFG1+I+FyF6qm37gM Kh0udXlAxQIeNZYdWMwG7BP6tJpynPc= X-Authority-Analysis: v=2.4 cv=btx8wkai c=1 sm=1 tr=0 ts=6a6243ed cx=c_pps a=RP+M6JBNLl+fLTcSJhASfg==:117 a=ki/9DncYKtdbYI9tCPo7qA==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=Um2Pa8k9VHT-vaBCBUpS:22 a=EUspDBNiAAAA:8 a=5vk8l6TQ9dB8fbFmZYYA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=iS9zxrgQBfv6-_F4QbHw:22 X-Proofpoint-ORIG-GUID: cFXEsJlBMZBTaDC48X8z4ONw0AbIBLwq X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-23_04,2026-07-22_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 malwarescore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 phishscore=0 priorityscore=1501 spamscore=0 bulkscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607230163 Hi Brian, On 23-07-2026 19:59, Brian Masney wrote: > Hi Praveen, > > On Thu, Jul 23, 2026 at 11:40:47AM +0530, Praveen Talari wrote: >> clk_round_rate() only checks for a NULL clk pointer before >> dereferencing it, but callers such as dev_pm_opp_set_rate() can pass >> it an error pointer (e.g. ERR_PTR(-ENOENT) left behind by >> clk_get() when a device has no Linux clock and is instead managed by >> firmware via a genpd/OPP performance domain). >> >> Dereferencing that error pointer to read clk->exclusive_count >> crashes with an unhandled kernel NULL pointer dereference, since >> ERR_PTR(-ENOENT) plus the field's offset lands on a small, unmapped >> address: >> >> Unable to handle kernel NULL pointer dereference at virtual >> address 000000000000002e >> ... >> pc : clk_round_rate+0x3c/0x188 >> ... >> Call trace: >> clk_round_rate+0x3c/0x188 (P) >> dev_pm_opp_set_rate+0x114/0x33c >> >> Change the guard from "if (!clk)" to "if (IS_ERR_OR_NULL(clk))", >> matching the pattern already used by other clk consumer API >> functions such as clk_unprepare(), so an error pointer is rejected >> the same way a NULL pointer is. >> >> Signed-off-by: Praveen Talari >> --- >> drivers/clk/clk.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c >> index 048adfa86a5d..8c1ad3d10284 100644 >> --- a/drivers/clk/clk.c >> +++ b/drivers/clk/clk.c >> @@ -1780,7 +1780,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate) >> struct clk_rate_request req; >> int ret; >> >> - if (!clk) >> + if (IS_ERR_OR_NULL(clk)) > Can you provide more details about the clk_get() call point that starts this > error? Specifically which driver this occurs in and the exact scenario that > triggers this. On SA8255P platform there is no Linux clock for the SE, and the perf domain device's OPPs are populated entirely from firmware via devm_pm_opp_of_add_table() (through of_genpd_add_provider_simple()/onecell()), so the perf domain's OPP table has entries even though no clk_get() ever succeeds for it. The clk_get(-ENOENT) case comes from _update_opp_table_clk() in drivers/opp/core.c:     opp_table->clk = clk_get(dev, NULL);     ret = PTR_ERR_OR_ZERO(opp_table->clk);     ...     if (ret == -ENOENT) {         /* ... no clk provided ... */         opp_table->clk_count = 1;         return opp_table;   /* opp_table->clk left as ERR_PTR(-ENOENT) */     } Because the perf domain device has no "clocks" property (its OPPs are supplied purely as performance states by firmware/genpd), clk_get() returns -ENOENT, and opp_table->clk is left holding that error pointer rather than being reset to NULL. Praveen > > Brian >