From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D78FC33CAC for ; Mon, 3 Feb 2020 10:30:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EF18420721 for ; Mon, 3 Feb 2020 10:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="sLDLnOJN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF18420721 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 80CC26B0634; Mon, 3 Feb 2020 05:29:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7BD7E6B0635; Mon, 3 Feb 2020 05:29:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6D3936B0636; Mon, 3 Feb 2020 05:29:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0123.hostedemail.com [216.40.44.123]) by kanga.kvack.org (Postfix) with ESMTP id 55AD26B0634 for ; Mon, 3 Feb 2020 05:29:59 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id E05788248047 for ; Mon, 3 Feb 2020 10:29:58 +0000 (UTC) X-FDA: 76448445276.27.fang29_74301a00adc02 X-HE-Tag: fang29_74301a00adc02 X-Filterd-Recvd-Size: 4095 Received: from mail-vs1-f74.google.com (mail-vs1-f74.google.com [209.85.217.74]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Mon, 3 Feb 2020 10:29:58 +0000 (UTC) Received: by mail-vs1-f74.google.com with SMTP id a197so1313895vsd.19 for ; Mon, 03 Feb 2020 02:29:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=cwfqPgJUbTD4a1lkaFtG9qiHd0yr+qeTZAkWv2HYTPE=; b=sLDLnOJN6EG98mEQu30IuDdOd5dIXCmLnLHXzVWF0m3WzJC9ogNG3MWRruxrEaDkDq +CsxZmDcMHUhwSAOgU68w0WsIs3Yctvu98UusWVe63jdIEi/5qGIzBy9da2sZFD2QPz7 xvDxN1Dj00vsOZaERPky0eLSh4s5bWDxc1cmF6+LseFjoc9XV1igMg4wRqOziEfLQQQe SrbbFjpz1vrVB6ZWXeJNNukkPCY64lDCVBQv1nzP1nhWCJnD3yliU2ikxjQqicisHRha /98Bk8IISXNIXrkv8IQEd8HxJuEAtBv+evhPMpHIoh8hrDS5sScQtjq7Rx7AkF950ocY mY/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=cwfqPgJUbTD4a1lkaFtG9qiHd0yr+qeTZAkWv2HYTPE=; b=gFL6jyjBCOQwMJ1P5bsnGRhzd2IJvh5afA5VUxDCYG+KlPgtDPucqd58DDZxIEQO1g 98VMG8ek6vU44CKEP0p6yONwJ0NQJZ3GYVE/NMUPM4DHklCMA4eDBdc+1R1IGnLcqaOW 8OOoEeOPqti0ztvFb9J22FuougDfPmeOBm1YfdVvR0YGMJxtLK8m/VA9334V1YFc3BxB hHChWISc2jxq0aPnykYMY2aYjFDUBcNO7HnRfJibsVBXruuS6PzoF/M0LnGx7PA6RRbO KdHz0GvisNi/dXzJDuYy0f5ouWKMMFuAuGL1rWq0w4reeD9Ndls+JxiodMZeyskbDiga 0/Lg== X-Gm-Message-State: APjAAAVkCG1gTogS2oFSlP9iVVNhKqoEwNF6+Q7Yzi8ED8dH8gyBtyVA GjuXW9XfT4u9pE8QvS5nK79lCCXGhVI= X-Google-Smtp-Source: APXvYqxbqkap8Izvg0vwKZMvAiuBMhQLZKnLK1xT3OHV/27L6WF/6JY2rtIw3BIjb/oqOH5GErOTuxW9VQ0= X-Received: by 2002:ac5:ce8f:: with SMTP id 15mr13534661vke.81.1580725797683; Mon, 03 Feb 2020 02:29:57 -0800 (PST) Date: Mon, 3 Feb 2020 11:29:53 +0100 Message-Id: <20200203102953.17349-1-glider@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog Subject: [PATCH] lib/stackdepot: fix global out-of-bounds in stack_slabs From: glider@google.com To: walter-zh.wu@mediatek.com, dvyukov@google.com, gregkh@linuxfoundation.org, akpm@linux-foundation.org Cc: matthias.bgg@gmail.com, tglx@linutronix.de, jpoimboe@redhat.com, kstewart@linuxfoundation.org, linux-mm@kvack.org, Alexander Potapenko Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Walter Wu has reported a potential case in which init_stack_slab() is called after stack_slabs[STACK_ALLOC_MAX_SLABS - 1] has already been initialized. In that case init_stack_slab() will overwrite stack_slabs[STACK_ALLOC_MAX_SLABS], which may result in a memory corruption. Fixes: cd11016e5f521 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB") Reported-by: Walter Wu Cc: Dmitry Vyukov Cc: Matthias Brugger Cc: Thomas Gleixner Cc: Josh Poimboeuf Cc: Kate Stewart Cc: Greg Kroah-Hartman Cc: Andrew Morton Signed-off-by: Alexander Potapenko --- lib/stackdepot.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/stackdepot.c b/lib/stackdepot.c index ed717dd08ff3..3580e92cac99 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -84,7 +84,9 @@ static bool init_stack_slab(void **prealloc) if (stack_slabs[depot_index] == NULL) { stack_slabs[depot_index] = *prealloc; } else { - stack_slabs[depot_index + 1] = *prealloc; + /* If this is the last depot slab, do not touch the next one. */ + if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) + stack_slabs[depot_index + 1] = *prealloc; /* * This smp_store_release pairs with smp_load_acquire() from * |next_slab_inited| above and in stack_depot_save(). -- 2.25.0.341.g760bfbb309-goog