From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Martin Steigerwald To: schmitzmic@gmail.com Cc: axboe@kernel.dk, geert@linux-m68k.org, jdow@earthlink.net, linux-m68k@lists.linux-m68k.org, linux-block@vger.kernel.org Subject: Re: Subject: [PATCH RFC] block: fix Amiga RDB partition support for disks >= 2 TB Date: Wed, 27 Jun 2018 10:13:46 +0200 Message-ID: <2906102.Jp2gmY2ce1@merkaba> In-Reply-To: <20180627012421.80B8F24E094@nmr-admin> References: <20180627012421.80B8F24E094@nmr-admin> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" List-ID: schmitzmic@gmail.com - 27.06.18, 03:24: > From 5299e0e64dfb33ac3a1f3137b42178734ce20087 Mon Sep 17 00:00:00 2001 >=20 > The Amiga RDB partition parser module uses int for partition sector > address and count, which will overflow for disks 2 TB and larger. >=20 > Use sector_t as type for sector address and size (as expected by > put_partition) to allow using such disks without danger of data > corruption. >=20 > This bug was reported originally in 2012 by Martin Steigerwald > , and the fix was created by the RDB author, > Joanne Dow . The patch had been discussed and > reviewed on linux-m68k at that time but never officially submitted. >=20 > Following a stern warning by Joanne, a warning is printed if any > partition is found to overflow the old 32 bit calculations, on the > grounds that such a partition would be misparses on legacy 32 bit > systems (other than Linux). >=20 > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=3D43511 > Reported-by: Martin Steigerwald > Message-ID: <201206192146.09327.Martin@lichtvoll.de> > Signed-off-by: Michael Schmitz > Tested-by: Martin Steigerwald > Tested-by: Michael Schmitz > --- > block/partitions/amiga.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) >=20 > diff --git a/block/partitions/amiga.c b/block/partitions/amiga.c > index 5609366..42c3f38 100644 > --- a/block/partitions/amiga.c > +++ b/block/partitions/amiga.c > @@ -32,7 +32,8 @@ int amiga_partition(struct parsed_partitions *state) > unsigned char *data; > struct RigidDiskBlock *rdb; > struct PartitionBlock *pb; > - int start_sect, nr_sects, blk, part, res =3D 0; > + sector_t start_sect, nr_sects; > + int blk, part, res =3D 0; > int blksize =3D 1; /* Multiplier for disk block size */ > int slot =3D 1; > char b[BDEVNAME_SIZE]; > @@ -111,6 +112,16 @@ int amiga_partition(struct parsed_partitions > *state) be32_to_cpu(pb->pb_Environment[3]) * > be32_to_cpu(pb->pb_Environment[5]) * > blksize; > + if (start_sect > INT_MAX || nr_sects > INT_MAX > + || (start_sect + nr_sects) > INT_MAX) { > + pr_err("%s: Warning: RDB partition overflow!\n", > + bdevname(state->bdev, b)); > + pr_err("%s: start 0x%llX size 0x%llX\n", > + bdevname(state->bdev, b), start_sect, > + nr_sects); > + pr_err("%s: partition incompatible with 32 bit OS\n", > + bdevname(state->bdev, b)); > + } I do think the wording of that warning is inaccurate, as outlined in my=20 other mails in thread "Re: moving affs + RDB partition support to=20 staging?" just a few minutes ago (see there for a more complete=20 reasoning). I=B4d word it like this: partition needs 64 bit disk device support in AmigaOS or AmigaOS like=20 operating systems (NSD64, TD64 or SCSI direct) I think I would not include any more details, and let Amiga people=20 research what they need and since when it is included officially on=20 their own. As there are at least three variants out there: AmigaOS,=20 MorphOS, AROS. AmigaOS 4 at least can handle disks of 2 TB size or more. I do not think=20 the wording "RDB overflow" is right either. http://wiki.amigaos.net/wiki/RDB =46ilesystem size limits are a different matter. http://www.amigawiki.de/doku.php?id=3Dde:system:filesystems_limits > put_partition(state,slot++,start_sect,nr_sects); > { > /* Be even more informative to aid mounting */ Thanks, =2D-=20 Martin