Commit 332ef331 authored Jul 01, 2007 by Stefan Richter

firewire: fw-sbp2: add a boundary check



Add rudimentary check for the case that the page table overflows due to
merging of s/g elements by the IOMMU.  This would have lead to
overwriting of arbitrary memory.

After this change I expect that an offending command will be
unsuccessfully retried until the scsi_device is taken offline by SCSI
core.  It's a border case and not worth to implement a recovery
strategy.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Kristian Høgsberg <krh@redhat.com>

parent 9fb2dd12

drivers/firewire/fw-sbp2.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -937,6 +937,11 @@ static int sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
		sg_len = sg_dma_len(sg + i);
		sg_addr = sg_dma_address(sg + i);
		while (sg_len) {
		/* FIXME: This won't get us out of the pinch. */
		if (unlikely(j >= ARRAY_SIZE(orb->page_table))) {
		fw_error("page table overflow\n");
		goto fail_page_table;
		}
		l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
		orb->page_table[j].low = sg_addr;
		orb->page_table[j].high = (l << 16);