Messages in this thread Patch in this message | | | Date | Sun, 11 Oct 2009 00:51:53 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] hfsplus: Refuse to mount volumes larger than 2TB |
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On Sun, 11 Oct 2009 03:11:27 +0100 Ben Hutchings <ben@decadent.org.uk> wrote:
> As found in <http://bugs.debian.org/550010>, hfsplus is using type u32 > rather than sector_t for some sector number calculations. > > In particular, hfsplus_get_block() does: > > u32 ablock, dblock, mask; > ... > map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask)); > > I am not confident that I can find and fix all cases where a sector > number may be truncated. For now, avoid data loss by refusing to mount > HFS+ volumes with more than 2^32 sectors (2TB). > > Signed-off-by: Ben Hutchings <ben@decadent.org.uk> > Cc: stable@kernel.org > --- > --- a/fs/hfsplus/wrapper.c > +++ b/fs/hfsplus/wrapper.c > @@ -99,6 +99,10 @@ > > if (hfsplus_get_last_session(sb, &part_start, &part_size)) > return -EINVAL; > + if (part_start + part_size > 0x100000000) { > + pr_err("hfs: volumes larger than 2TB are not supported yet\n"); > + return -EINVAL; > + }
part_start and part_size are sector_t. This code will do weird overflow things when sector_t is 32-bit. Also 32-bit compilers will get upset at the excessively large hex constant.
This should fix both issues:
--- a/fs/hfsplus/wrapper.c~hfsplus-refuse-to-mount-volumes-larger-than-2tb-fix +++ a/fs/hfsplus/wrapper.c @@ -99,7 +99,7 @@ int hfsplus_read_wrapper(struct super_bl if (hfsplus_get_last_session(sb, &part_start, &part_size)) return -EINVAL; - if (part_start + part_size > 0x100000000) { + if ((u64)part_start + part_size > 0x100000000ULL) { pr_err("hfs: volumes larger than 2TB are not supported yet\n"); return -EINVAL; } _
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