target_core_rd: break out unterminated loop during copy

The loop in rd_execute_rw() will never terminate if the
sg element has a zero size. Or it'll spill over into
outer space if the sg element is larger than the available
space.
So we need to add some safety catches here.

Cc: Nic Bellinger <nab@risingtidesystems.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Hannes Reinecke 2013-02-06 14:42:28 +01:00 committed by Nicholas Bellinger
parent 1b7f390eb3
commit bbf344e54e

View File

@ -316,7 +316,19 @@ rd_execute_rw(struct se_cmd *cmd)
void *rd_addr;
sg_miter_next(&m);
if (!(u32)m.length) {
pr_debug("RD[%u]: invalid sgl %p len %zu\n",
dev->rd_dev_id, m.addr, m.length);
sg_miter_stop(&m);
return TCM_INCORRECT_AMOUNT_OF_DATA;
}
len = min((u32)m.length, src_len);
if (len > rd_size) {
pr_debug("RD[%u]: size underrun page %d offset %d "
"size %d\n", dev->rd_dev_id,
rd_page, rd_offset, rd_size);
len = rd_size;
}
m.consumed = len;
rd_addr = sg_virt(rd_sg) + rd_offset;