[SCSI] sg: fix iovec bugs introduced by the block layer conversion

- needs to use copy_from_user for iovec before passing it to
blk_rq_map_user_iov().

- before the block layer conversion, if ->dxfer_len and sum of iovec
disagrees, the shorter one wins. However, currently sg returns
-EINVAL. This restores the old behavior.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
FUJITA Tomonori 2009-04-03 09:12:20 +09:00 committed by James Bottomley
parent f894e74dc1
commit 0fdf96b67a

View File

@ -1656,10 +1656,30 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
md->null_mapped = hp->dxferp ? 0 : 1;
}
if (iov_count)
res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
hp->dxfer_len, GFP_ATOMIC);
else
if (iov_count) {
int len, size = sizeof(struct sg_iovec) * iov_count;
struct iovec *iov;
iov = kmalloc(size, GFP_ATOMIC);
if (!iov)
return -ENOMEM;
if (copy_from_user(iov, hp->dxferp, size)) {
kfree(iov);
return -EFAULT;
}
len = iov_length(iov, iov_count);
if (hp->dxfer_len < len) {
iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
len = hp->dxfer_len;
}
res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
iov_count,
len, GFP_ATOMIC);
kfree(iov);
} else
res = blk_rq_map_user(q, rq, md, hp->dxferp,
hp->dxfer_len, GFP_ATOMIC);