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fs/read_write.c:compat_readv(): remove bogus area verify 

The compat_do_readv_writev() function was doing a verify_area on the
incoming iov, but the nr_segs value is not checked.  If someone passes
in a -1 for nr_segs, for instance, the function should return an EINVAL.
However, it returns a EFAULT because the verify_area fails because it is
checking an array of size MAX_UINT.  The check is bogus, anyway, because
the next check, compat_rw_copy_check_uvector(), will do all the
necessary checking, anyway.  The non-compat do_readv_writev() function
doesn't do this check, so I think it's safe to just remove the code.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Corey Minyard 2014-01-21 15:48:44 -08:00 committed by Linus Torvalds
parent 38316c8ab7
commit 4e4f9e66a7
1 changed files with 0 additions and 4 deletions
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4
fs/read_write.c
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@ -901,10 +901,6 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
io_fn_t fn;
iov_fn_t fnv;
ret = -EFAULT;
if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
goto out;
ret = compat_rw_copy_check_uvector(type, uvector, nr_segs,
UIO_FASTIOV, iovstack, &iov);
if (ret <= 0)