subroutine R63W72() intentionally overwrites array memory

[edwardhartnett]

In R63W72() we have this chilling comment:

C> @note kgds and igds extend beyond their dimensions here
C> if pl parameters are present.

When this function is called from some NCEPLIBS-g2 function during testing, this condition can be found. See NOAA-EMC/NCEPLIBS-g2#385.

In the subroutine we have:

      SUBROUTINE R63W72(KPDS,KGDS,IPDS,IGDS)
      DIMENSION KPDS(200),KGDS(200),IPDS(200),IGDS(200)

and later:

C  EXTENSION FOR PL PARAMETERS
      IF(KGDS(1).EQ.0.AND.KGDS(19).EQ.0.AND.KGDS(20).NE.255) THEN
        DO J=1,KGDS(3)
          IGDS(18+J)=KGDS(21+J)
        ENDDO
      ENDIF

If KGDS(3) > 179, this will overwrite the boundary of the KGDS array.

I'm not sure what to do about this. @GeorgeGayno-NOAA or @GeorgeVandenberghe-NOAA do you know why this would be done?

[GeorgeVandenberghe-NOAA]

I have no idea why this was done. I am tempted to make the overwrite fatal

On Tuesday, October 3, 2023, Edward Hartnett ***@***.***> wrote: In R63W72() we have this chilling comment: C> @note kgds and igds extend beyond their dimensions here C> if pl parameters are present. When this function is called from some NCEPLIBS-g2 function during

testing, this condition can be found. See NOAA-EMC/NCEPLIBS-g2#385.

In the subroutine we have: SUBROUTINE R63W72(KPDS,KGDS,IPDS,IGDS) DIMENSION KPDS(200),KGDS(200),IPDS(200),IGDS(200) and later: C EXTENSION FOR PL PARAMETERS IF(KGDS(1).EQ.0.AND.KGDS(19).EQ.0.AND.KGDS(20).NE.255) THEN DO J=1,KGDS(3) IGDS(18+J)=KGDS(21+J) ENDDO ENDIF If KGDS(3) > 179, this will overwrite the boundary of the KGDS array. I'm not sure what to do about this. @GeorgeGayno-NOAA or

@GeorgeVandenberghe-NOAA do you know why this would be done?

— Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you were mentioned.<

https://ci6.googleusercontent.com/proxy/5K8RNJyqaXkC8HGxUtPhKMDwN1SjTELdois61C7kDZl2jp4dKqaaLFWxm8akMXhb7wtehGmMH_uK5P36_vlw3hhhk0etlUbvu8BBNVbuDcFfpbuCBMUymG9urZocM-EJP7FaEd2XESV8KnnRO6HV7s5ih_WOg6WaHC45o2FjMN_24A8znb0Gc4JO0fdpO3VKyATIDKUoDOYU10KEZpaY3UpjWv2qUCgO25A=s0-d-e1-ft#https://github.com/notifications/beacon/ANDS4FWEWLLMASCRKMW52XDX5P7DXA5CNFSM6AAAAAA5Q4S2PSWGG33NNVSW45C7OR4XAZNFJFZXG5LFVJRW63LNMVXHIX3JMTHHFLQPKQ.gif>Message ID: ***@***.***>

…

-- George W Vandenberghe *Lynker Technologies at * NOAA/NWS/NCEP/EMC 5830 University Research Ct., Rm. 2141 College Park, MD 20740 ***@***.*** 301-683-3769(work) 3017751547(cell)

[GeorgeVandenberghe-NOAA]

We can't tolerate out of bounds memory overwrites deep in our dependencies. On Tuesday, October 3, 2023, George Vandenberghe - NOAA Affiliate < ***@***.***> wrote:

I have no idea why this was done. I am tempted to make the overwrite fatal On Tuesday, October 3, 2023, Edward Hartnett ***@***.***>

wrote:

> In R63W72() we have this chilling comment: > > C> @note kgds and igds extend beyond their dimensions here > C> if pl parameters are present. > > When this function is called from some NCEPLIBS-g2 function during

testing, this condition can be found. See NOAA-EMC/NCEPLIBS-g2#385.

> > In the subroutine we have: > > SUBROUTINE R63W72(KPDS,KGDS,IPDS,IGDS) > DIMENSION KPDS(200),KGDS(200),IPDS(200),IGDS(200) > > and later: > > C EXTENSION FOR PL PARAMETERS > IF(KGDS(1).EQ.0.AND.KGDS(19).EQ.0.AND.KGDS(20).NE.255) THEN > DO J=1,KGDS(3) > IGDS(18+J)=KGDS(21+J) > ENDDO > ENDIF > > If KGDS(3) > 179, this will overwrite the boundary of the KGDS array. > > I'm not sure what to do about this. @GeorgeGayno-NOAA or

@GeorgeVandenberghe-NOAA do you know why this would be done?

> > — > Reply to this email directly, view it on GitHub, or unsubscribe. > You are receiving this because you were mentioned.<

https://ci6.googleusercontent.com/proxy/5K8RNJyqaXkC8HGxUtPhKMDwN1SjTELdois61C7kDZl2jp4dKqaaLFWxm8akMXhb7wtehGmMH_uK5P36_vlw3hhhk0etlUbvu8BBNVbuDcFfpbuCBMUymG9urZocM-EJP7FaEd2XESV8KnnRO6HV7s5ih_WOg6WaHC45o2FjMN_24A8znb0Gc4JO0fdpO3VKyATIDKUoDOYU10KEZpaY3UpjWv2qUCgO25A=s0-d-e1-ft#https://github.com/notifications/beacon/ANDS4FWEWLLMASCRKMW52XDX5P7DXA5CNFSM6AAAAAA5Q4S2PSWGG33NNVSW45C7OR4XAZNFJFZXG5LFVJRW63LNMVXHIX3JMTHHFLQPKQ.gif>Message ID: ***@***.***>

…

-- George W Vandenberghe Lynker Technologies at NOAA/NWS/NCEP/EMC 5830 University Research Ct., Rm. 2141 College Park, MD 20740 ***@***.*** 301-683-3769(work) 3017751547(cell)

-- George W Vandenberghe *Lynker Technologies at * NOAA/NWS/NCEP/EMC 5830 University Research Ct., Rm. 2141 College Park, MD 20740 ***@***.*** 301-683-3769(work) 3017751547(cell)