Subject: + fs-read_writec-compat_readv-remove-bogus-area-verify.patch added to -mm tree
To: minyard@xxxxxxx,cminyard@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 07 Jan 2014 15:03:24 -0800
The patch titled
Subject: fs/read_write.c:compat_readv(): remove bogus area verify
has been added to the -mm tree. Its filename is
fs-read_writec-compat_readv-remove-bogus-area-verify.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/fs-read_writec-compat_readv-remove-bogus-area-verify.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/fs-read_writec-compat_readv-remove-bogus-area-verify.patch
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------------------------------------------------------
From: Corey Minyard <minyard@xxxxxxx>
Subject: 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@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/read_write.c | 4 ----
1 file changed, 4 deletions(-)
diff -puN fs/read_write.c~fs-read_writec-compat_readv-remove-bogus-area-verify fs/read_write.c
--- a/fs/read_write.c~fs-read_writec-compat_readv-remove-bogus-area-verify
+++ a/fs/read_write.c
@@ -901,10 +901,6 @@ static ssize_t compat_do_readv_writev(in
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)
_
Patches currently in -mm which might be from minyard@xxxxxxx are
fs-read_writec-compat_readv-remove-bogus-area-verify.patch
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