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>
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index b0fff52..e0b3c37 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -316,7 +316,19 @@
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;