From nobody Fri Apr 3 02:23:00 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EAF1ECAAD8 for ; Fri, 16 Sep 2022 23:33:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbiIPXdZ (ORCPT ); Fri, 16 Sep 2022 19:33:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229519AbiIPXdX (ORCPT ); Fri, 16 Sep 2022 19:33:23 -0400 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D0CB9595; Fri, 16 Sep 2022 16:33:22 -0700 (PDT) Received: by mail-pg1-x52e.google.com with SMTP id r23so13113105pgr.6; Fri, 16 Sep 2022 16:33:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date; bh=FkwcMuPKAyIP/oOmQ4uH+hyF+kMKI0zxNAQqGfbM4Z8=; b=S9cmbn4CyhtMlh6aNtSmNTJvFCO+Yuk/HR7QzXFPqpi2dDaDucz2dfmEcw/fswaD0u vCn+FvnuVGFtJ0lX49P4LuJHW50golAAP+ehiTfuV4WcWJcjLDv+8c8oqajhE52hSU9S 3b/X0EqXFkHkCzD9K+qbnJq4fwYM/lUMh1aAfRX+9fWc5hzuGr/CGQtalLuPjwvajL3t 4Z7klohE2d00G2bCBnrkINzOrND/AcgRZmwNfYCTGNxYmWwmbY+SRF4cuBD46V3D34zt Wy+EBjmoII++9HSuIZkc1xgLXJvGyUsrtDZX8oAeVl3+eT9at7TURsRiNDbgNc0Ej/4d 4jjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date; bh=FkwcMuPKAyIP/oOmQ4uH+hyF+kMKI0zxNAQqGfbM4Z8=; b=s0eAbKnMr20Qq6avWrDB3sQzSwVzTacLUyrq8GiHN1V5KrD12t+OqsZ65o/HZ2CCoT UC4Bj2nY9NHHeWcVu0l3b1esvmxyr0e2i8v8yExE+tQu2fAE31wMpeEYp6kqSDP5Bdbr Ce5ehsUXzJqKKLAKjVvGVjv7QwV56de43YnE8mVm784mJSVbN+zpsg8eiPAJ6JoNr+3h RMlBdH1n/BOGLjJtZqB+95u/Z+TP/1rop8bNdGwUfx7sPYHd4kZCd3DfgWVE71FLCWSx y6MA3YPK7U6YVmmNMujEZDt8ilhFU8EJ9yAtOxYqUK1+8g4xNlLQsbFijth+soTXO+zz QwtQ== X-Gm-Message-State: ACrzQf3yZ0MdnXdhkdiVkPM0dAKAumBXxn9QYoAPmNotMzNr/ADwWnU/ XM4mptZwOVeewF1VaWhO10q6WXbMAmk= X-Google-Smtp-Source: AMsMyM54vHxTNdmLHLU1J//l6ttbSdd442EteUL6rW2u3LeoAdFWAJeGCW+zEpHLpwdaEd/qTAnSmw== X-Received: by 2002:a63:4714:0:b0:42b:82d9:b617 with SMTP id u20-20020a634714000000b0042b82d9b617mr6308979pga.223.1663371201616; Fri, 16 Sep 2022 16:33:21 -0700 (PDT) Received: from localhost.localdomain (lily-optiplex-3070.dynamic.ucsd.edu. [2607:f720:1300:3033::1:4dd]) by smtp.googlemail.com with ESMTPSA id g2-20020a170902d1c200b001781a7c28b9sm14578525plb.240.2022.09.16.16.33.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Sep 2022 16:33:20 -0700 (PDT) From: Li Zhong To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Cc: song@kernel.org, Li Zhong Subject: [PATCH v2] drivers/md/md-bitmap: check the return value of md_bitmap_get_counter() Date: Fri, 16 Sep 2022 16:33:05 -0700 Message-Id: <20220916233305.3784826-1-floridsleeves@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Check the return value of md_bitmap_get_counter() in case it returns NULL pointer, which will result in a null pointer dereference. v2: update the check to include other dereference Signed-off-by: Li Zhong --- drivers/md/md-bitmap.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index bf6dffadbe6f..63ece30114e5 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2195,20 +2195,23 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_= t blocks, =20 if (set) { bmc_new =3D md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, = 1); - if (*bmc_new =3D=3D 0) { - /* need to set on-disk bits too. */ - sector_t end =3D block + new_blocks; - sector_t start =3D block >> chunkshift; - start <<=3D chunkshift; - while (start < end) { - md_bitmap_file_set_bit(bitmap, block); - start +=3D 1 << chunkshift; + if (bmc_new) { + if (*bmc_new =3D=3D 0) { + /* need to set on-disk bits too. */ + sector_t end =3D block + new_blocks; + sector_t start =3D block >> chunkshift; + + start <<=3D chunkshift; + while (start < end) { + md_bitmap_file_set_bit(bitmap, block); + start +=3D 1 << chunkshift; + } + *bmc_new =3D 2; + md_bitmap_count_page(&bitmap->counts, block, 1); + md_bitmap_set_pending(&bitmap->counts, block); } - *bmc_new =3D 2; - md_bitmap_count_page(&bitmap->counts, block, 1); - md_bitmap_set_pending(&bitmap->counts, block); + *bmc_new |=3D NEEDED_MASK; } - *bmc_new |=3D NEEDED_MASK; if (new_blocks < old_blocks) old_blocks =3D new_blocks; } --=20 2.25.1