On Mon, May 22, 2017 at 8:05 AM, Varun Prakash <varun@xxxxxxxxxxx> wrote: > On Tue, May 09, 2017 at 03:34:44PM -0700, Kees Cook wrote: >> When copying attributes, the len argument was padded out and the resulting >> memcpy() would copy beyond the end of the source buffer. Avoid this, >> and use size_t for val_len to avoid all the casts. Similarly, avoid source >> buffer casts and use void *. >> >> Additionally enforces val_len can be represented by u16 and that >> the DMA buffer was not overflowed. Fixes the size of mfa, which is not >> FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN (but it will be padded up to 4). This >> was noticed by the future CONFIG_FORTIFY_SOURCE checks. >> >> Cc: Daniel Micay <danielmicay@xxxxxxxxx> >> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> >> --- >> drivers/scsi/csiostor/csio_lnode.c | 43 +++++++++++++++++++++++--------------- >> 1 file changed, 26 insertions(+), 17 deletions(-) >> >> diff --git a/drivers/scsi/csiostor/csio_lnode.c b/drivers/scsi/csiostor/csio_lnode.c >> index c00b2ff72b55..be5ee2d37815 100644 >> --- a/drivers/scsi/csiostor/csio_lnode.c >> +++ b/drivers/scsi/csiostor/csio_lnode.c >> @@ -238,14 +238,23 @@ csio_osname(uint8_t *buf, size_t buf_len) >> } >> > > >> >> csio_append_attrib(&pld, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD, >> - (uint8_t *)&maxpayload, >> - FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN); >> + &maxpayload, FC_FDMI_HBA_ATTR_MAXCTPAYLOAD_LEN); >> len = (uint32_t)(pld - (uint8_t *)cmd); >> numattrs++; >> attrib_blk->numattrs = htonl(numattrs); >> @@ -1794,6 +1801,8 @@ csio_ln_mgmt_submit_req(struct csio_ioreq *io_req, >> struct csio_mgmtm *mgmtm = csio_hw_to_mgmtm(hw); >> int rv; >> >> + BUG_ON(pld_len > pld->len); >> + > > I think WARN_ON() is better than BUG_ON() in this case > > if (WARN_ON(pld_len > pld->len)) > return -EINVAL; > >> io_req->io_cbfn = io_cbfn; /* Upper layer callback handler */ >> io_req->fw_handle = (uintptr_t) (io_req); >> io_req->eq_idx = mgmtm->eq_idx; I chose BUG_ON here because the damage has already been done. If this assertion is hit, the heap buffers have already been overrun. This isn't a state we should only warn about... -Kees -- Kees Cook Pixel Security
