From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EC981ED38 for ; Tue, 25 Jul 2023 11:25:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6E81C433C8; Tue, 25 Jul 2023 11:25:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690284330; bh=T3i1HTZBPyzEbzqZTXzzY5G70qq1TRHwkWnt5ZgAjLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rTxaXPo0Le+09a60Akm1jXs/SlpWDueuFGE66HE9zoob0v3re5WCTeJwloGV3OVvz ApwQEt4wqShemDu2x/kA2vizWaFhlmv1+ILLKTe1WkrM6g6G0KjQlz7sCzbLFWTE67 MF4sylukz8ejCKgy2PsBq5f10Bt/d03s8an8aCjQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Martin Steigerwald , Michael Schmitz , Geert Uytterhoeven , Christoph Hellwig , Jens Axboe Subject: [PATCH 5.10 310/509] block: add overflow checks for Amiga partition support Date: Tue, 25 Jul 2023 12:44:09 +0200 Message-ID: <20230725104607.934620100@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104553.588743331@linuxfoundation.org> References: <20230725104553.588743331@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Michael Schmitz commit b6f3f28f604ba3de4724ad82bea6adb1300c0b5f upstream. 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 patch 1 in this series). This patch adds additional error checking and warning messages. Reported-by: Martin Steigerwald Closes: https://bugzilla.kernel.org/show_bug.cgi?id=43511 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Message-ID: <201206192146.09327.Martin@lichtvoll.de> Cc: # 5.2 Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230620201725.7020-4-schmitzmic@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/partitions/amiga.c | 103 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 85 insertions(+), 18 deletions(-) --- a/block/partitions/amiga.c +++ b/block/partitions/amiga.c @@ -11,10 +11,18 @@ #define pr_fmt(fmt) fmt #include +#include +#include #include #include "check.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) { @@ -31,9 +39,12 @@ int amiga_partition(struct parsed_partit 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]; @@ -42,7 +53,7 @@ int amiga_partition(struct parsed_partit goto rdb_done; data = read_part_sector(state, blk, §); if (!data) { - pr_err("Dev %s: unable to read RDB block %d\n", + pr_err("Dev %s: unable to read RDB block %llu\n", bdevname(state->bdev, b), blk); res = -1; goto rdb_done; @@ -59,12 +70,12 @@ int amiga_partition(struct parsed_partit *(__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", + pr_err("Trashed word at 0xd0 in block %llu ignored in checksum calculation\n", blk); break; } - pr_err("Dev %s: RDB in block %d has bad checksum\n", + pr_err("Dev %s: RDB in block %llu has bad checksum\n", bdevname(state->bdev, b), blk); } @@ -81,10 +92,15 @@ int amiga_partition(struct parsed_partit 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! Skipping partitions %u and beyond\n", + bdevname(state->bdev, b), blk, part); + break; + } data = read_part_sector(state, blk, §); if (!data) { - pr_err("Dev %s: unable to read partition block %d\n", + pr_err("Dev %s: unable to read partition block %llu\n", bdevname(state->bdev, b), blk); res = -1; goto rdb_done; @@ -96,19 +112,70 @@ int amiga_partition(struct parsed_partit 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, end_sect); + continue; + } + + /* Tell Kernel about it */ + put_partition(state,slot++,start_sect,nr_sects); { /* Be even more informative to aid mounting */