From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2071) id 7AEA13858400; Sun, 19 Dec 2021 20:14:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7AEA13858400 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Harald Anlauf To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-9403] Fortran: PACK intrinsic should not try to read from zero-sized array X-Act-Checkin: gcc X-Git-Author: Harald Anlauf X-Git-Refname: refs/heads/releases/gcc-11 X-Git-Oldrev: 4f9ad140c6c2ca51b591f44f7579cc3b81356291 X-Git-Newrev: 05640d5ca8a20929f30eef41baee3e4a8d85c898 Message-Id: <20211219201422.7AEA13858400@sourceware.org> Date: Sun, 19 Dec 2021 20:14:22 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Dec 2021 20:14:22 -0000 https://gcc.gnu.org/g:05640d5ca8a20929f30eef41baee3e4a8d85c898 commit r11-9403-g05640d5ca8a20929f30eef41baee3e4a8d85c898 Author: Harald Anlauf Date: Mon Dec 13 20:50:19 2021 +0100 Fortran: PACK intrinsic should not try to read from zero-sized array libgfortran/ChangeLog: PR libfortran/103634 * intrinsics/pack_generic.c (pack_internal): Handle case when the array argument of PACK has one or more extents of size zero to avoid invalid reads. gcc/testsuite/ChangeLog: PR libfortran/103634 * gfortran.dg/intrinsic_pack_6.f90: New test. (cherry picked from commit 1c613165a55b212c59a83796b20a1d555e096504) Diff: --- gcc/testsuite/gfortran.dg/intrinsic_pack_6.f90 | 57 ++++++++++++++++++++++++++ libgfortran/intrinsics/pack_generic.c | 9 ++++ 2 files changed, 66 insertions(+) diff --git a/gcc/testsuite/gfortran.dg/intrinsic_pack_6.f90 b/gcc/testsuite/gfortran.dg/intrinsic_pack_6.f90 new file mode 100644 index 00000000000..917944d8846 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/intrinsic_pack_6.f90 @@ -0,0 +1,57 @@ +! { dg-do run } +! PR libfortran/103634 - Runtime crash with PACK on zero-sized arrays +! Exercise PACK intrinsic for cases when it calls pack_internal + +program p + implicit none + type t + real :: r(24) = -99. + end type + type(t), allocatable :: new(:), old(:), vec(:) + logical, allocatable :: mask(:) + integer :: n, m +! m = 1 ! works + m = 0 ! failed with SIGSEGV in pack_internal + do m = 0, 2 + print *, m + allocate (old(m), mask(m), vec(m)) + if (m > 0) vec(m)% r(1) = 42 + mask(:) = .true. + n = count (mask) + allocate (new(n)) + + mask(:) = .false. + if (size (pack (old, mask)) /= 0) stop 1 + mask(:) = .true. + if (size (pack (old, mask)) /= m) stop 2 + new(:) = pack (old, mask) ! this used to segfault for m=0 + + mask(:) = .false. + if (size (pack (old, mask, vector=vec)) /= m) stop 3 + new(:) = t() + new(:) = pack (old, mask, vector=vec) ! this used to segfault for m=0 + if (m > 0) then + if ( new( m )% r(1) /= 42) stop 4 + if (any (new(:m-1)% r(1) /= -99)) stop 5 + end if + + if (m > 0) mask(m) = .true. + if (size (pack (old, mask, vector=vec)) /= m) stop 6 + new(:) = t() + new(:) = pack (old, mask, vector=vec) ! this used to segfault for m=0 + if (m > 0) then + if (new(1)% r(1) /= -99) stop 7 + end if + if (m > 1) then + if (new(m)% r(1) /= 42) stop 8 + end if + + if (size (pack (old(:0), mask(:0), vector=vec)) /= m) stop 9 + new(:) = t() + new(:) = pack (old(:0), mask(:0), vector=vec) ! did segfault for m=0 + if (m > 0) then + if (new(m)% r(1) /= 42) stop 10 + end if + deallocate (old, mask, new, vec) + end do +end diff --git a/libgfortran/intrinsics/pack_generic.c b/libgfortran/intrinsics/pack_generic.c index cad2fbbfbcd..15880e74348 100644 --- a/libgfortran/intrinsics/pack_generic.c +++ b/libgfortran/intrinsics/pack_generic.c @@ -85,6 +85,7 @@ pack_internal (gfc_array_char *ret, const gfc_array_char *array, index_type count[GFC_MAX_DIMENSIONS]; index_type extent[GFC_MAX_DIMENSIONS]; + bool zero_sized; index_type n; index_type dim; index_type nelem; @@ -114,10 +115,13 @@ pack_internal (gfc_array_char *ret, const gfc_array_char *array, else runtime_error ("Funny sized logical array"); + zero_sized = false; for (n = 0; n < dim; n++) { count[n] = 0; extent[n] = GFC_DESCRIPTOR_EXTENT(array,n); + if (extent[n] <= 0) + zero_sized = true; sstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(array,n); mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n); } @@ -126,6 +130,11 @@ pack_internal (gfc_array_char *ret, const gfc_array_char *array, if (mstride[0] == 0) mstride[0] = mask_kind; + if (zero_sized) + sptr = NULL; + else + sptr = array->base_addr; + if (ret->base_addr == NULL || unlikely (compile_options.bounds_check)) { /* Count the elements, either for allocating memory or