From: Stefan Richter Date: Sun, 1 Jul 2007 11:56:03 +0000 (+0200) Subject: firewire: fw-sbp2: add a boundary check X-Git-Tag: MMI-PSA29.97-13-9~42388^2~3 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=332ef3310bc37ff29fd4382d6dfb38a787078091;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git 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 Acked-by: Kristian Høgsberg --- diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index 212674d723e3..c7518ea4c8ee 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);