From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from integral2.. (unknown [182.2.70.248]) by gnuweeb.org (Postfix) with ESMTPSA id 6FA437EDA2; Tue, 1 Mar 2022 07:24:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1646119476; bh=oduq7UbWH4yY7hi8T5IT1C8abw9Vor905WGb4sLdUnQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TBp3j/Fqcss/3NXNfLhqpiGq5+F0a9kmmYlsNW76kM7KmCFmclci5SUTGrefVy4hI nHCjc50jwNtfVCX20O/xJ6TgHUdOsXLmtoymbV7hlCwZjeplUEUrYqFh9ldjzay1oB cXEoeHFXVHtC/fqYGbtYQS4j0PH+q7siofvBQfXlmLTdZJRYc+CuAEDXezp5zwSFQ+ 4YyZz/XcQph1EBDf35eeLE1gvCX9agwvxrUMJUdrMPcFjHq3mNaluHQmEMRTV1DqID MbPTqDd8DfVbV6dOPNlNbFpgHI++HPnzTuYTImQIyipG7jhrGgbYt0IuLJ44mesSWE P04lgLLNjtOTA== From: Ammar Faizi To: Borislav Petkov Cc: Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , Tony Luck , linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, gwml@vger.gnuweeb.org, x86@kernel.org, stable@vger.kernel.org, Ammar Faizi Subject: [PATCH 2/2] x86/mce/amd: Fix memory leak when `threshold_create_bank()` fails Date: Tue, 1 Mar 2022 14:23:53 +0700 Message-Id: <20220301072353.95749-3-ammarfaizi2@gnuweeb.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220301072353.95749-1-ammarfaizi2@gnuweeb.org> References: <20220301072353.95749-1-ammarfaizi2@gnuweeb.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: @bp is a local variable, calling mce_threshold_remove_device() when threshold_create_bank() fails will not free the @bp. Note that mce_threshold_remove_device() frees the @bp only if it's already stored in the @threshold_banks per-CPU variable. At that point, the @threshold_banks per-CPU variable is still NULL, so the mce_threshold_remove_device() will just be a no-op and the @bp is leaked. Fix this by calling kfree() and early returning when we fail. This bug is introduced by commit 6458de97fc15530b544 ("x86/mce/amd: Straighten CPU hotplug path") [1]. Link: https://lore.kernel.org/all/20200403161943.1458-6-bp@alien8.de [1] Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Tony Luck Fixes: 6458de97fc15530b54477c4e2b70af653e8ac3d9 ("x86/mce/amd: Straighten CPU hotplug path") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Ammar Faizi --- arch/x86/kernel/cpu/mce/amd.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index 9f4b508886dd..75d019dfe8d6 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -1350,15 +1350,14 @@ int mce_threshold_create_device(unsigned int cpu) if (!(this_cpu_read(bank_map) & (1 << bank))) continue; err = threshold_create_bank(bp, cpu, bank); - if (err) - goto out_err; + if (err) { + kfree(bp); + return err; + } } this_cpu_write(threshold_banks, bp); if (thresholding_irq_en) mce_threshold_vector = amd_threshold_interrupt; return 0; -out_err: - mce_threshold_remove_device(cpu); - return err; } -- 2.32.0