From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6085118BC23 for ; Fri, 25 Oct 2024 18:20:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729880453; cv=none; b=nwcGlbwvNu0bTkt2kfjlXl7ohasbyHQAEvMLbiEIkMf0Kr7F09wxdl5wCSsy9Evl+nOuffGYEfaBf6wqf9IseG4e2OnoKXVtjiOhBkSOPyFf4o9jTZU120kDUUU42oBJZn/rECrKa357STrqAdDb6/F8ctmXpoFWJyPEPu9pQcU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729880453; c=relaxed/simple; bh=a6zZTZkAMo+zqGztqVGNTRaIEb0mb+Y9Lnu9Gu2Sp4Q=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=LooYJcsIsjvLtpEGUXYaaa3gmmdmB7CgIM8WusaNchIS9Pay3rkqbFAO8kdgvbl2RZNwde7A/Q3egxmiMGn0P1c9GbCA65a7b9s6+NMcaYEkygXVy9h1pIgfJKj6JU+hBswkrmZK1m4S8duxgqf89eJz5RzVAGB8j/LB1CS5cec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=1BNiwmkf; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="1BNiwmkf" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-71ebf65fe6bso2373255b3a.0 for ; Fri, 25 Oct 2024 11:20:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1729880451; x=1730485251; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=M/FzCKkZzvJstDaLglCOzaVhmGuwzgqmPghGo88HmjU=; b=1BNiwmkfRukInRzQLU4ubIKcLpbABrGklXskqw3nH0IcFx3Ui/X4X7UHxs3zHwjNeY v/lZED8gbCk7RN/JbFaI7Ot17BTXzERQj1AqAdcyG3G0Oe7pHBT2kXkf6P5oP32F5aIC MMVcJJYmsYubWkiJGodNQdkafnrh2D4M1O5JGADx/eIymVx9Y6FB+CwYQRvAMULf+577 hxbrOY6hR6ugNpsiAoKJSbdT8t7y6/k/02H/yUOiw1oXmJon77RiXBPLSJQVl8ORLkI/ XoekzS33pCZphbgNiEukoUM2POiRv67wi5jON8jOGzVPmaQOq1uMf0LogojsqXTYBmAE 9h4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729880451; x=1730485251; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=M/FzCKkZzvJstDaLglCOzaVhmGuwzgqmPghGo88HmjU=; b=H7p4J65+68VoiRcAqCjc6moDRaefWpPJkKDayA4Xtw2I8jwRCAjXrFD951gaodaaTr Y1Lp89k1FgBF/tp4Bmx9nK+p4BST9uycQ33DbXNi2jhAsC6Wyo4Lp9SkD9NhG/jizoBA DYXe4C1HMfwKGId9qZdpWmWxCCWx2A70SlMv5zYp9VHDfwUDyJE+SPYenjFBfceEjHm0 gEVioRnehz66iI5hoVzOCM+9CMkGFQBnZ7xKvh6h7Ua2zXmlTmwupUtwc2SyrwqdCwMD DONq5nLmJwhfUwJBSX+myaP9kbGjt9LxeSC4LEIcXr0U74ZmFWv799wBwaH1QcAP493l JDjw== X-Gm-Message-State: AOJu0YxtBAyJWwFPXM8VXNga4M4+Ll+yalyEO2pWX+tnecn8Ie6V+XZK kgpfKKt2kU3hIJYWKz/rsHDR7n3wL933dtAcvL1U+sGFtqoMOl+4Sd2k6ZjyKzvUNAwM/NqV2fd SyH3y/AsNuzO47t998E+s+fVPc/b7mM8Up6kdsfILREbqVEWompBtyF06gKRiKEYjEk2ITYkqff pDfVPv9bVsI3+QB66CJhxLKjCEUdUgO10ph7UUmUhC6c+A X-Google-Smtp-Source: AGHT+IGnEjihC5QbbL3J0qlq7fny5Hy+kLzJtJIRG8GaZmdm1jyWlF/JXP/IRPAnbG+VFdX38Pas6Pay3VAF X-Received: from jstultz-noogler2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:600]) (user=jstultz job=sendgmr) by 2002:a05:6a00:6518:b0:71e:50e2:5f6f with SMTP id d2e1a72fcca58-72062a4eeeamr399b3a.0.1729880449560; Fri, 25 Oct 2024 11:20:49 -0700 (PDT) Date: Fri, 25 Oct 2024 11:20:33 -0700 In-Reply-To: <20241025182042.131384-1-jstultz@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241025182042.131384-1-jstultz@google.com> X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <20241025182042.131384-2-jstultz@google.com> Subject: [RFC][PATCH v2 2/2] lib: stackdepot: Avoid null pointer if stack_depot_save is called too early From: John Stultz To: LKML Cc: John Stultz , Steven Rostedt , Alexander Potapenko , Andrey Konovalov , Andrew Morton , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" If stack_depot_save is called before stackdepot has initialized a null reference to the stack_table might be used, crashing the system. Instead, check stack_table has been initialized before going further. Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrew Morton Cc: kernel-team@android.com Signed-off-by: John Stultz --- lib/stackdepot.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 5ed34cc963fc..09780c835362 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -611,6 +611,9 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, if (unlikely(nr_entries == 0) || stack_depot_disabled) return 0; + if (!stack_table) + return 0; + hash = hash_stack(entries, nr_entries); bucket = &stack_table[hash & stack_hash_mask]; -- 2.47.0.163.g1226f6d8fa-goog