Messages in this thread | | | Date | Thu, 31 Oct 2013 19:06:08 +0000 | From | Al Viro <> | Subject | Re: [PATCH] fs/befs/linuxvfs.c: need signed cast for variable 'block' |
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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?
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