From patchwork Sun Oct 14 04:48:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Schmitz X-Patchwork-Id: 10640513 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3E63914BD for ; Sun, 14 Oct 2018 04:48:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E7002A41F for ; Sun, 14 Oct 2018 04:48:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1BE772A42A; Sun, 14 Oct 2018 04:48:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6437B2A41F for ; Sun, 14 Oct 2018 04:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726089AbeJNM2Z (ORCPT ); Sun, 14 Oct 2018 08:28:25 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:38213 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725987AbeJNM2Z (ORCPT ); Sun, 14 Oct 2018 08:28:25 -0400 Received: by mail-pf1-f193.google.com with SMTP id f29-v6so8075544pff.5; Sat, 13 Oct 2018 21:48:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=apk8SDC2X69dYNKuZ+B1p6EVSVWVMQJ1vuSUxUSDyfg=; b=teu/or7yW7LDkEB6HQGCv5XGiuY+78xACk0cWpJUUmo+jX1BuLR584r6XBl9CG3JtS QruJsZSkYGjRvcz/LhblVYdragQ+RIK8hNw2vi2CkMGIhdtLSqUTa9QgX3NlAbeXo1mT e33+qqKGRH2BfVM0zEXQS9/eapH3rqnJNdkf8jwSXs3h5oTv6HjeWhJUdv9u/DPH7i7y ykSzTOD/js+V3yth7Kvmkb2eh56tmpQkOx0D9XF7Irwj1dx1E+ufm1GQt5YEuKEdXi5S V5TAxOuhn3VHIuU8t4luDPyr0E/xDt1XBfj2d7htK0t4gwzspGxc4KF9/Y+PpNavmpv/ vqXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=apk8SDC2X69dYNKuZ+B1p6EVSVWVMQJ1vuSUxUSDyfg=; b=pG/WVBbd/wNIDMnJgF7b0JJBIF9+M0b90b9vXCJs3RF5BwX9R7J2iLE0bQ8evenHwj jy9sWqAs5bbS9WsGpC7qo3rqY73f3RJSo7Vyh9/POvVqS2qWPut8BbIXthybWEkga94q L01h4HCVVMgKWXotIZCdoorIBkorXX5evQWbgxtlfNPoVxNRg6sFsbD9QtQy41jpa/NE eAMAqkDBHFj5uqcYve7VmcraiChUB5J4StsKfbtqS82lUvZFG+KMQ6C27WiSxCFKvdt+ L1/wWO5l2Sixpw9cVFvuqCj7kVg3isNaevpgw76tNSaqzjb0wlY5DYlM9J5q9BN9uMYT LDOw== X-Gm-Message-State: ABuFfohM9fKJZvz4vQGqakhqrYr4ElJ1He5XsJcJTFanYtIR7xWW1BQv /ENVZ34KW/5P9zxXh7m0kM4= X-Google-Smtp-Source: ACcGV61Cgo7HAp3H/PFeaHHzKrYdRUlJz4Pw6Qh9/CDXxPxBdF+lzdHCf5DBbUYj8SzBssZlJkOkLQ== X-Received: by 2002:a62:ca4d:: with SMTP id n74-v6mr12315517pfg.10.1539492523286; Sat, 13 Oct 2018 21:48:43 -0700 (PDT) Received: from xplor.waratah.dyndns.org (122-62-216-69-adsl.sparkbb.co.nz. [122.62.216.69]) by smtp.gmail.com with ESMTPSA id e9-v6sm6931507pgs.92.2018.10.13.21.48.40 (version=TLS1 cipher=AES128-SHA bits=128/128); Sat, 13 Oct 2018 21:48:41 -0700 (PDT) Received: by xplor.waratah.dyndns.org (Postfix, from userid 1000) id 40542360082; Sun, 14 Oct 2018 17:48:37 +1300 (NZDT) From: Michael Schmitz To: linux-block@vger.kernel.org, axboe@kernel.dk Cc: linux-m68k@vger.kernel.org, geert@linux-m68k.org, Michael Schmitz Subject: [PATCH v6 2/2] block: add overflow checks for Amiga partition support Date: Sun, 14 Oct 2018 17:48:35 +1300 Message-Id: <1539492515-1782-3-git-send-email-schmitzmic@gmail.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1539492515-1782-1-git-send-email-schmitzmic@gmail.com> References: <1539492515-1782-1-git-send-email-schmitzmic@gmail.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The Amiga partition parser module uses signed int for partition sector address and count, which will overflow for disks larger than 1 TB. Use u64 as type for sector address and size to allow using disks up to 2 TB without LBD support, and disks larger than 2 TB with LBD. The RBD format allows to specify disk sizes up to 2^128 bytes (though native OS limitations reduce this somewhat, to max 2^68 bytes), so check for u64 overflow carefully to protect against overflowing sector_t. Bail out if sector addresses overflow 32 bits on kernels without LBD support. This bug was reported originally in 2012, and the fix was created by the RDB author, Joanne Dow . A patch had been discussed and reviewed on linux-m68k at that time but never officially submitted (now resubmitted as separate patch). This patch adds additional error checking and warning messages. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=43511 Reported-by: Martin Steigerwald Message-ID: <201206192146.09327.Martin@lichtvoll.de> Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven --- Changes from RFC: - use u64 instead of sector_t, since that may be u32 without LBD support - check multiplication overflows each step - 3 u32 values may exceed u64! - warn against use on AmigaDOS if partition data overflow u32 sector count. - warn if partition CylBlocks larger than what's stored in the RDSK header. - bail out if we were to overflow sector_t (32 or 64 bit). Changes from v1: Kars de Jong: - use defines for magic offsets in DosEnvec struct Geert Uytterhoeven: - use u64 cast for multiplications of u32 numbers - use array3_size for overflow checks - change pr_err to pr_warn - discontinue use of pr_cont - reword log messages - drop redundant nr_sects overflow test - warn against 32 bit overflow for each affected partition - skip partitions that overflow sector_t size instead of aborting scan Changes from v2: - further trim 32 bit overflow test - correct duplicate types.h inclusion introduced in v2 Changes from v3: - split off sector address type fix for independent review - change blksize to unsigned - use check_mul_overflow() instead of array3_size() - rewrite checks to avoid 64 bit divisions in check_mul_overflow() Changes from v5: Geert Uytterhoeven: - correct ineffective u64 cast to avoid 32 bit mult. overflow - fix mult. overflow in partition block address calculation --- block/partitions/amiga.c | 112 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 90 insertions(+), 22 deletions(-) diff --git a/block/partitions/amiga.c b/block/partitions/amiga.c index 7ea9540..24d4138 100644 --- a/block/partitions/amiga.c +++ b/block/partitions/amiga.c @@ -11,11 +11,19 @@ #define pr_fmt(fmt) fmt #include +#include +#include #include #include "check.h" #include "amiga.h" +/* magic offsets in partition DosEnvVec */ +#define NR_HD 3 +#define NR_SECT 5 +#define LO_CYL 9 +#define HI_CYL 10 + static __inline__ u32 checksum_block(__be32 *m, int size) { @@ -32,9 +40,12 @@ int amiga_partition(struct parsed_partitions *state) unsigned char *data; struct RigidDiskBlock *rdb; struct PartitionBlock *pb; - sector_t start_sect, nr_sects; - int blk, part, res = 0; - int blksize = 1; /* Multiplier for disk block size */ + u64 start_sect, nr_sects; + sector_t blk, end_sect; + u32 cylblk; /* rdb_CylBlocks = nr_heads*sect_per_track */ + u32 nr_hd, nr_sect, lo_cyl, hi_cyl; + int part, res = 0; + unsigned int blksize = 1; /* Multiplier for disk block size */ int slot = 1; char b[BDEVNAME_SIZE]; @@ -44,8 +55,8 @@ int amiga_partition(struct parsed_partitions *state) data = read_part_sector(state, blk, §); if (!data) { if (warn_no_part) - pr_err("Dev %s: unable to read RDB block %d\n", - bdevname(state->bdev, b), blk); + pr_err("Dev %s: unable to read RDB block %llu\n", + bdevname(state->bdev, b), (u64) blk); res = -1; goto rdb_done; } @@ -61,13 +72,13 @@ int amiga_partition(struct parsed_partitions *state) *(__be32 *)(data+0xdc) = 0; if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) { - pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n", - blk); + pr_err("Trashed word at 0xd0 in block %llu ignored in checksum calculation\n", + (u64) blk); break; } - pr_err("Dev %s: RDB in block %d has bad checksum\n", - bdevname(state->bdev, b), blk); + pr_err("Dev %s: RDB in block %llu has bad checksum\n", + bdevname(state->bdev, b), (u64) blk); } /* blksize is blocks per 512 byte standard block */ @@ -83,12 +94,18 @@ int amiga_partition(struct parsed_partitions *state) blk = be32_to_cpu(rdb->rdb_PartitionList); put_dev_sector(sect); for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) { - blk *= blksize; /* Read in terms partition table understands */ + /* Read in terms partition table understands */ + if (check_mul_overflow(blk, (sector_t) blksize, &blk)) { + pr_err("Dev %s: overflow calculating partition block %llu!\n", + bdevname(state->bdev, b), (u64) blk); + res = -1; + goto rdb_done; + } data = read_part_sector(state, blk, §); if (!data) { if (warn_no_part) - pr_err("Dev %s: unable to read partition block %d\n", - bdevname(state->bdev, b), blk); + pr_err("Dev %s: unable to read partition block %llu\n", + bdevname(state->bdev, b), (u64) blk); res = -1; goto rdb_done; } @@ -99,19 +116,70 @@ int amiga_partition(struct parsed_partitions *state) if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 ) continue; - /* Tell Kernel about it */ + /* RDB gives us more than enough rope to hang ourselves with, + * many times over (2^128 bytes if all fields max out). + * Some careful checks are in order, so check for potential + * overflows. + * We are multiplying four 32 bit numbers to one sector_t! + */ + + nr_hd = be32_to_cpu(pb->pb_Environment[NR_HD]); + nr_sect = be32_to_cpu(pb->pb_Environment[NR_SECT]); + + /* CylBlocks is total number of blocks per cylinder */ + if (check_mul_overflow(nr_hd, nr_sect, &cylblk)) { + pr_err("Dev %s: heads*sects %u overflows u32, skipping partition!\n", + bdevname(state->bdev, b), cylblk); + continue; + } + + /* check for consistency with RDB defined CylBlocks */ + if (cylblk > be32_to_cpu(rdb->rdb_CylBlocks)) { + pr_warn("Dev %s: cylblk %u > rdb_CylBlocks %u!\n", + bdevname(state->bdev, b), cylblk, + be32_to_cpu(rdb->rdb_CylBlocks)); + } + + /* RDB allows for variable logical block size - + * normalize to 512 byte blocks and check result. + */ + + if (check_mul_overflow(cylblk, blksize, &cylblk)) { + pr_err("Dev %s: partition %u bytes per cyl. overflows u32, skipping partition!\n", + bdevname(state->bdev, b), part); + continue; + } + + /* Calculate partition start and end. Limit of 32 bit on cylblk + * guarantees no overflow occurs if LBD support is enabled. + */ + + lo_cyl = be32_to_cpu(pb->pb_Environment[LO_CYL]); + start_sect = ((u64) lo_cyl * cylblk); + + hi_cyl = be32_to_cpu(pb->pb_Environment[HI_CYL]); + nr_sects = (((u64) hi_cyl - lo_cyl + 1) * cylblk); - nr_sects = ((sector_t) be32_to_cpu(pb->pb_Environment[10]) - + 1 - be32_to_cpu(pb->pb_Environment[9])) * - be32_to_cpu(pb->pb_Environment[3]) * - be32_to_cpu(pb->pb_Environment[5]) * - blksize; if (!nr_sects) continue; - start_sect = (sector_t) be32_to_cpu(pb->pb_Environment[9]) * - be32_to_cpu(pb->pb_Environment[3]) * - be32_to_cpu(pb->pb_Environment[5]) * - blksize; + + /* Warn user if partition end overflows u32 (AmigaDOS limit) */ + + if ((start_sect + nr_sects) > UINT_MAX) { + pr_warn("Dev %s: partition %u (%llu-%llu) needs 64 bit device support!\n", + bdevname(state->bdev, b), part, + start_sect, start_sect + nr_sects); + } + + if (check_add_overflow(start_sect, nr_sects, &end_sect)) { + pr_err("Dev %s: partition %u (%llu-%llu) needs LBD device support, skipping partition!\n", + bdevname(state->bdev, b), part, + start_sect, (u64) end_sect); + continue; + } + + /* Tell Kernel about it */ + put_partition(state,slot++,start_sect,nr_sects); { /* Be even more informative to aid mounting */