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authorStefan Richter <stefanr@s5r6.in-berlin.de>2007-07-01 13:56:03 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2007-07-10 00:07:47 +0200
commit332ef3310bc37ff29fd4382d6dfb38a787078091 (patch)
tree63313482ee19fffea5900bacf52c1c660528f72a
parent9fb2dd12c019965ffd15e5a0727af14488b3a772 (diff)
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>
-rw-r--r--drivers/firewire/fw-sbp2.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 212674d723e..c7518ea4c8e 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -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);