Messages in this thread |  | | Date | Thu, 31 Oct 2013 12:08:33 -0700 | Subject | Re: [PATCH] fs/befs/linuxvfs.c: need signed cast for variable 'block' | From | Kees Cook <> |
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On Thu, Oct 31, 2013 at 12:06 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > On Thu, Oct 31, 2013 at 09:53:59AM -0700, Kees Cook wrote: > >> If block (type sector_t) is unsigned, we shouldn't cast it signed. >> This entire code path should be removed. What is BEFS's expected >> maximum block size? (Looks like even befs_blocknr_t is u64, so nothing >> seems trivially in danger of wrapping.) I would also note that all the >> format strings are wrong too (%ld instead of %lu). > > FWIW, this > res = befs_fblock2brun(sb, ds, block, &run); > if (res != BEFS_OK) { > befs_error(sb, > "<--- befs_get_block() for inode %lu, block " > "%ld ERROR", inode->i_ino, block); > return -EFBIG; > } > also looks wrong - ioctl(..., FIBMAP, ...) shouldn't be able to spew > printks on a valid fs and hitting it with block number greater than > file length will, AFAICS, trigger that. > > I agree that this code needs fixing, but just making gcc STFU about the > comparison would only serve to hide the problem. Anybody familiar with > befs or willing to learn it?
Agreed. MAINTAINERS shows it as orphaned. Perhaps it should be moved into staging?
-Kees
-- Kees Cook Chrome OS Security
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