On Thu, Oct 03, 2019 at 11:08:03PM +0100, Colin Ian King wrote: > Hi, > > Static analysis with Coverity has detected a potential issue with > function validate_bksv in > drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c with recent > commit: > > commit ed9d8e2bcb003ec94658cafe9b1bb3960e2139ec > Author: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx> > Date: Tue Aug 6 17:52:01 2019 -0400 > > drm/amd/display: Add HDCP module I think the real question here is ... why is this not using drm_hdcp? -Daniel > > > The analysis is as follows: > > 28 static inline enum mod_hdcp_status validate_bksv(struct mod_hdcp *hdcp) > 29 { > > CID 89852 (#1 of 1): Out-of-bounds read (OVERRUN) > > 1. overrun-local: > Overrunning array of 5 bytes at byte offset 7 by dereferencing pointer > (uint64_t *)hdcp->auth.msg.hdcp1.bksv. > > 30 uint64_t n = *(uint64_t *)hdcp->auth.msg.hdcp1.bksv; > 31 uint8_t count = 0; > 32 > 33 while (n) { > 34 count++; > 35 n &= (n - 1); > 36 } > > hdcp->auth.msg.hdcp1.bksv is an array of 5 uint8_t as defined in > drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h as follows: > > struct mod_hdcp_message_hdcp1 { > uint8_t an[8]; > uint8_t aksv[5]; > uint8_t ainfo; > uint8_t bksv[5]; > uint16_t r0p; > uint8_t bcaps; > uint16_t bstatus; > uint8_t ksvlist[635]; > uint16_t ksvlist_size; > uint8_t vp[20]; > > uint16_t binfo_dp; > }; > > variable n is going to contain the contains of r0p and bcaps. I'm not > sure if that is intentional. If not, then the count is going to be > incorrect if these are non-zero. > > Colin -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx