[v3] Add reallocarray function.

Submitted by Dennis Wölfing on April 21, 2017, 12:16 p.m.

Details

Message ID 20170421121646.28392-1-denniswoelfing@gmx.de
State New
Headers show

Commit Message

Dennis Wölfing April 21, 2017, 12:16 p.m.
The reallocarray function is an extension from OpenBSD.  It is an
integer-overflow-safe replacement for realloc(p, X*Y) and
malloc(X*Y) (realloc(NULL, X*Y)).  It can therefore help in preventing
certain security issues in code.

This is an updated version of a patch originally submitted by Rüdiger
Sonderfeld in May 2014.
See <https://sourceware.org/ml/libc-alpha/2014-05/msg00481.html>.

Tested on x86_64-linux.

2017-04-21  Dennis Wölfing  <denniswoelfing@gmx.de>
            Rüdiger Sonderfeld  <ruediger@c-plusplus.de>

	* NEWS: Mention addition of reallocarray.
	* malloc/Makefile (routines): Add reallocarray.
	(tests): Add tst-reallocarray.c.
	* malloc/Versions: Add reallocarray and __libc_reallocarray.
	* malloc/malloc-private.h: New file.
	* malloc/malloc.c (__libc_calloc): Use `check_mul_overflow'.
	* malloc/malloc.h (reallocarray): New declaration.
	* stdlib/stdlib.h (reallocarray): Likewise.
	* malloc/reallocarray.c: New file.
	* malloc/tst-reallocarray.c: New test file.
	* manual/memory.texi: Document reallocarray.
	* sysdeps/arm/nacl/libc.abilist: Add reallocarray.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
---
 NEWS                                               |   2 +
 malloc/Makefile                                    |   4 +-
 malloc/Versions                                    |   4 +
 malloc/malloc-private.h                            |  44 ++++++
 malloc/malloc.c                                    |  14 +-
 malloc/malloc.h                                    |   8 ++
 malloc/reallocarray.c                              |  36 +++++
 malloc/tst-reallocarray.c                          | 159 +++++++++++++++++++++
 manual/memory.texi                                 |  24 +++-
 stdlib/stdlib.h                                    |  11 ++
 sysdeps/arm/nacl/libc.abilist                      |   2 +
 sysdeps/unix/sysv/linux/aarch64/libc.abilist       |   2 +
 sysdeps/unix/sysv/linux/alpha/libc.abilist         |   2 +
 sysdeps/unix/sysv/linux/arm/libc.abilist           |   2 +
 sysdeps/unix/sysv/linux/hppa/libc.abilist          |   2 +
 sysdeps/unix/sysv/linux/i386/libc.abilist          |   2 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist          |   2 +
 sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |   2 +
 sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |   2 +
 sysdeps/unix/sysv/linux/microblaze/libc.abilist    |   2 +
 .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |   2 +
 .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |   2 +
 .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |   2 +
 .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |   2 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist         |   2 +
 .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |   2 +
 .../linux/powerpc/powerpc32/nofpu/libc.abilist     |   2 +
 .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |   2 +
 .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |   2 +
 sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |   2 +
 sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |   2 +
 sysdeps/unix/sysv/linux/sh/libc.abilist            |   2 +
 sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |   2 +
 sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |   2 +
 .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |   2 +
 .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |   2 +
 sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |   2 +
 sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |   2 +
 sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |   2 +
 39 files changed, 350 insertions(+), 14 deletions(-)
 create mode 100644 malloc/malloc-private.h
 create mode 100644 malloc/reallocarray.c
 create mode 100644 malloc/tst-reallocarray.c

Comments

Dennis Wölfing April 28, 2017, 8:57 a.m.
On 21.04.2017 14:16, Dennis Wölfing wrote:
> The reallocarray function is an extension from OpenBSD.  It is an
> integer-overflow-safe replacement for realloc(p, X*Y) and
> malloc(X*Y) (realloc(NULL, X*Y)).  It can therefore help in preventing
> certain security issues in code.
> 
> This is an updated version of a patch originally submitted by Rüdiger
> Sonderfeld in May 2014.
> See <https://sourceware.org/ml/libc-alpha/2014-05/msg00481.html>.
> 
> Tested on x86_64-linux.
> 
> 2017-04-21  Dennis Wölfing  <denniswoelfing@gmx.de>
>             Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
> 
> 	* NEWS: Mention addition of reallocarray.
> 	* malloc/Makefile (routines): Add reallocarray.
> 	(tests): Add tst-reallocarray.c.
> 	* malloc/Versions: Add reallocarray and __libc_reallocarray.
> 	* malloc/malloc-private.h: New file.
> 	* malloc/malloc.c (__libc_calloc): Use `check_mul_overflow'.
> 	* malloc/malloc.h (reallocarray): New declaration.
> 	* stdlib/stdlib.h (reallocarray): Likewise.
> 	* malloc/reallocarray.c: New file.
> 	* malloc/tst-reallocarray.c: New test file.
> 	* manual/memory.texi: Document reallocarray.
> 	* sysdeps/arm/nacl/libc.abilist: Add reallocarray.
> 	* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.

Ping
Dennis Wölfing May 8, 2017, 7:07 a.m.
On 28.04.2017 10:57, Dennis Wölfing wrote:
> On 21.04.2017 14:16, Dennis Wölfing wrote:
>> The reallocarray function is an extension from OpenBSD.  It is an
>> integer-overflow-safe replacement for realloc(p, X*Y) and
>> malloc(X*Y) (realloc(NULL, X*Y)).  It can therefore help in preventing
>> certain security issues in code.
>>
>> This is an updated version of a patch originally submitted by Rüdiger
>> Sonderfeld in May 2014.
>> See <https://sourceware.org/ml/libc-alpha/2014-05/msg00481.html>.
>>
>> Tested on x86_64-linux.
>>
>> 2017-04-21  Dennis Wölfing  <denniswoelfing@gmx.de>
>>             Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
>>
>> 	* NEWS: Mention addition of reallocarray.
>> 	* malloc/Makefile (routines): Add reallocarray.
>> 	(tests): Add tst-reallocarray.c.
>> 	* malloc/Versions: Add reallocarray and __libc_reallocarray.
>> 	* malloc/malloc-private.h: New file.
>> 	* malloc/malloc.c (__libc_calloc): Use `check_mul_overflow'.
>> 	* malloc/malloc.h (reallocarray): New declaration.
>> 	* stdlib/stdlib.h (reallocarray): Likewise.
>> 	* malloc/reallocarray.c: New file.
>> 	* malloc/tst-reallocarray.c: New test file.
>> 	* manual/memory.texi: Document reallocarray.
>> 	* sysdeps/arm/nacl/libc.abilist: Add reallocarray.
>> 	* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
>> 	Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
>> 	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
>
> Ping

Ping 2. This patch
<https://sourceware.org/ml/libc-alpha/2017-04/msg00454.html>
is still pending.
Florian Weimer May 8, 2017, 7:34 a.m.
On 04/21/2017 02:16 PM, Dennis Wölfing wrote:
> +static void
> +merror (const char *msg)
> +{
> +  ++errors;
> +  printf ("Error: %s.\n", msg);
> +}

I don't think this provides additional useful information compared to 
TEST_VERIFY, so you could simply use that.  It's also not necessary to 
free pointers on test failure paths (for allocations which succeeded, 
but should not have), so you can simplify the test a bit further.

Further comments:

In check_mul_overflow, you can use a local variable instead of the 
preprocessor macro HALF_INTERNAL_SIZE_T.

An interposed malloc will not use INTERNAL_SIZE_T and will not interpose 
reallocarray, so reallocarray will fail allocations when it does not 
have to.  I think you need too check_mul_overflow variants, one for use 
in calloc (with INTERNAL_SIZE_T), and one for use in reallocarray.  It's 
probably best to leave calloc alone in this patch and only add a 
size_t-based check_mul_overflow in this patch.

You should add

libc_hidden_proto (__libc_reallocarray)

to include/stdlib.h, matched by

libc_hidden_def (__libc_reallocarray)

in malloc/reallocarray.c.  This way, libc-internal calls to reallocarray 
will not go through the PLT.

I'm not sure if the alias machinery in malloc/reallocarray.c is correct. 
  I think you only need a weak_alias for reallocarray.  (It has to be 
weak to support static linking of glibc-internal calls to 
__libc_reallocarray, without conflicting with a user-supplied 
reallocarray function.)

Otherwise, the patch looks good.

Thanks,
Florian

Patch hide | download patch | download mbox

diff --git a/NEWS b/NEWS
index 811178bca6..eaee4af5f5 100644
--- a/NEWS
+++ b/NEWS
@@ -52,6 +52,8 @@  Version 2.26
 * The legacy cfree function has been removed.  Applications should use the
   free function instead.
 
+* The reallocarray function has been added to libc.
+
 Security related changes:
 
 * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
diff --git a/malloc/Makefile b/malloc/Makefile
index e93b83b57d..6534594f7f 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -26,7 +26,7 @@  dist-headers := malloc.h
 headers := $(dist-headers) obstack.h mcheck.h
 tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
 	 tst-mallocstate tst-mcheck tst-mallocfork tst-trim1 \
-	 tst-malloc-usable tst-realloc tst-posix_memalign \
+	 tst-malloc-usable tst-realloc tst-reallocarray tst-posix_memalign \
 	 tst-pvalloc tst-memalign tst-mallopt tst-scratch_buffer \
 	 tst-malloc-backtrace tst-malloc-thread-exit \
 	 tst-malloc-thread-fail tst-malloc-fork-deadlock \
@@ -47,7 +47,7 @@  endif
 tests += $(tests-static)
 test-srcs = tst-mtrace
 
-routines = malloc morecore mcheck mtrace obstack \
+routines = malloc morecore mcheck mtrace obstack reallocarray \
   scratch_buffer_grow scratch_buffer_grow_preserve \
   scratch_buffer_set_array_size
 
diff --git a/malloc/Versions b/malloc/Versions
index e34ab177be..23aafb5ccc 100644
--- a/malloc/Versions
+++ b/malloc/Versions
@@ -62,6 +62,7 @@  libc {
     aligned_alloc;
   }
   GLIBC_2.26 {
+    reallocarray;
   }
   GLIBC_PRIVATE {
     # Internal startup hook for libpthread.
@@ -74,5 +75,8 @@  libc {
     __libc_scratch_buffer_grow;
     __libc_scratch_buffer_grow_preserve;
     __libc_scratch_buffer_set_array_size;
+
+    # Internal name for reallocarray
+    __libc_reallocarray;
   }
 }
diff --git a/malloc/malloc-private.h b/malloc/malloc-private.h
new file mode 100644
index 0000000000..56b9fbd708
--- /dev/null
+++ b/malloc/malloc-private.h
@@ -0,0 +1,44 @@ 
+/* Private declarations for malloc, for use within libc.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef _MALLOC_PRIVATE_H
+#define _MALLOC_PRIVATE_H
+
+#include <malloc/malloc-internal.h>
+
+static inline bool
+check_mul_overflow (size_t l, size_t r, INTERNAL_SIZE_T *result)
+{
+#if __GNUC__ >= 5
+  return __builtin_mul_overflow (l, r, result);
+#else
+  /* size_t is unsigned so the behavior on overflow is defined.  */
+  *result = l * r;
+# define HALF_INTERNAL_SIZE_T                                   \
+  (((INTERNAL_SIZE_T) 1) << (8 * sizeof (INTERNAL_SIZE_T) / 2))
+  if (__glibc_unlikely ((l | r) >= HALF_INTERNAL_SIZE_T))
+    {
+      if (r != 0 && *result / r != l)
+        return true;
+    }
+  return false;
+# undef HALF_INTERNAL_SIZE_T
+#endif
+}
+
+#endif /* _MALLOC_PRIVATE_H */
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 068ffc1684..a21910c4eb 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -239,6 +239,7 @@ 
 #include <libc-pointer-arith.h>
 
 #include <malloc/malloc-internal.h>
+#include <malloc/malloc-private.h>
 
 /*
   Debugging:
@@ -3179,17 +3180,10 @@  __libc_calloc (size_t n, size_t elem_size)
   unsigned long nclears;
   INTERNAL_SIZE_T *d;
 
-  /* size_t is unsigned so the behavior on overflow is defined.  */
-  bytes = n * elem_size;
-#define HALF_INTERNAL_SIZE_T \
-  (((INTERNAL_SIZE_T) 1) << (8 * sizeof (INTERNAL_SIZE_T) / 2))
-  if (__builtin_expect ((n | elem_size) >= HALF_INTERNAL_SIZE_T, 0))
+  if (check_mul_overflow (n, elem_size, &bytes))
     {
-      if (elem_size != 0 && bytes / elem_size != n)
-        {
-          __set_errno (ENOMEM);
-          return 0;
-        }
+      __set_errno (ENOMEM);
+      return 0;
     }
 
   void *(*hook) (size_t, const void *) =
diff --git a/malloc/malloc.h b/malloc/malloc.h
index 274c0958e4..339ab64c7d 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -49,6 +49,14 @@  __THROW __attribute_malloc__ __wur;
 extern void *realloc (void *__ptr, size_t __size)
 __THROW __attribute_warn_unused_result__;
 
+/* Re-allocate the previously allocated block in PTR, making the new
+   block large enough for NMEMB elements of SIZE bytes each.  */
+/* __attribute_malloc__ is not used, because if reallocarray returns
+   the same pointer that was passed to it, aliasing needs to be allowed
+   between objects pointed by the old and new pointers.  */
+extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)
+__THROW __attribute_warn_unused_result__;
+
 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 extern void free (void *__ptr) __THROW;
 
diff --git a/malloc/reallocarray.c b/malloc/reallocarray.c
new file mode 100644
index 0000000000..0755f2ab90
--- /dev/null
+++ b/malloc/reallocarray.c
@@ -0,0 +1,36 @@ 
+/* Change the size of an allocated block.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <malloc.h>
+#include <malloc/malloc-private.h>
+
+void *
+__libc_reallocarray (void *optr, size_t nmemb, size_t elem_size)
+{
+  INTERNAL_SIZE_T bytes;
+  if (check_mul_overflow (nmemb, elem_size, &bytes))
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+  else
+    return realloc (optr, bytes);
+}
+
+strong_alias (__libc_reallocarray, __reallocarray)
+weak_alias (__libc_reallocarray, reallocarray)
diff --git a/malloc/tst-reallocarray.c b/malloc/tst-reallocarray.c
new file mode 100644
index 0000000000..2d82c9d3da
--- /dev/null
+++ b/malloc/tst-reallocarray.c
@@ -0,0 +1,159 @@ 
+/* Test for reallocarray.
+   Copyright (C) 2014-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <string.h>
+
+static int errors = 0;
+
+static void
+merror (const char *msg)
+{
+  ++errors;
+  printf ("Error: %s.\n", msg);
+}
+
+static int
+do_test (void)
+
+{
+  void *ptr = NULL;
+  void *ptr2 = NULL;
+  unsigned char *c;
+  size_t i;
+  int ok;
+  const size_t max = ~(size_t)0;
+  size_t a, b;
+
+  /* Test overflow detection.  */
+  errno = 0;
+  ptr = reallocarray (NULL, max, 2);
+  if (ptr)
+    {
+      merror ("Overflow for size_t MAX * 2 not detected");
+      free (ptr);
+    }
+  else if (errno != ENOMEM)
+    merror ("errno is not set correctly");
+
+  errno = 0;
+  ptr = reallocarray (NULL, 2, max);
+  if (ptr)
+    {
+      merror ("Overflow for 2 * size_t MAX not detected");
+      free (ptr);
+    }
+  else if (errno != ENOMEM)
+    merror ("errno is not set correctly");
+
+  a = 65537;
+  b = max/65537 + 1;
+  errno = 0;
+  ptr = reallocarray (NULL, a, b);
+  if (ptr)
+    {
+      merror ("Overflow for (size_t MAX/65537 + 1) * 65537 not detected");
+      free (ptr);
+    }
+  else if (errno != ENOMEM)
+    merror ("errno is not set correctly");
+
+  errno = 0;
+  ptr = reallocarray (NULL, b, a);
+  if (ptr)
+    {
+      merror ("Overflow for 65537 * (size_t MAX/65537 + 1)  not detected");
+      free (ptr);
+    }
+  else if (errno != ENOMEM)
+    merror ("errno is not set correctly");
+
+  /* Test realloc-like behavior.  */
+  /* Allocate memory like malloc.  */
+  ptr = reallocarray (NULL, 10, 2);
+  if (!ptr)
+    merror ("realloc(NULL, 10, 2) failed");
+
+  memset (ptr, 0xAF, 10*2);
+
+  /* Enlarge buffer.   */
+  ptr2 = reallocarray (ptr, 20, 2);
+  if (!ptr2)
+    merror ("realloc(ptr, 20, 2) failed (enlarge)");
+  else
+    ptr = ptr2;
+
+  c = ptr;
+  ok = 1;
+  for (i = 0; i < 10*2; ++i)
+    {
+      if (c[i] != 0xAF)
+        ok = 0;
+    }
+  if (!ok)
+    merror ("Enlarging changed buffer content (10*2)");
+
+  /* Decrease buffer size.  */
+  ptr2 = reallocarray (ptr, 5, 3);
+  if (!ptr2)
+    merror ("realloc(ptr, 5, 3) failed (decrease)");
+  else
+    ptr = ptr2;
+
+  c = ptr;
+  ok = 1;
+  for (i = 0; i < 5*3; ++i)
+    {
+      if (c[i] != 0xAF)
+        ok = 0;
+    }
+  if (!ok)
+    merror ("Reducing changed buffer content (5*3)");
+
+  /* Overflow should leave buffer untouched.  */
+  errno = 0;
+  ptr2 = reallocarray (ptr, 2, ~(size_t)0);
+  if (ptr2)
+    merror ("realloc(ptr, 2, size_t MAX) failed to detect overflow");
+  if (errno != ENOMEM)
+    merror ("errno not set correctly");
+
+  c = ptr;
+  ok = 1;
+  for (i = 0; i < 5*3; ++i)
+    {
+      if (c[i] != 0xAF)
+        ok = 0;
+    }
+  if (!ok)
+    merror ("Overflow changed buffer content (5*3)");
+
+  /* Free buffer (glibc).  */
+  errno = 0;
+  ptr2 = reallocarray (ptr, 0, 0);
+  if (ptr2)
+    merror ("reallocarray (ptr, 0, 0) returned non-NULL");
+
+  free (ptr2);
+
+  return errors != 0;
+}
+
+#include <support/test-driver.c>
diff --git a/manual/memory.texi b/manual/memory.texi
index a256ca07b2..9758365eb7 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -751,8 +751,8 @@  be a buffer that you use to hold a line being read from a file; no matter
 how long you make the buffer initially, you may encounter a line that is
 longer.
 
-You can make the block longer by calling @code{realloc}.  This function
-is declared in @file{stdlib.h}.
+You can make the block longer by calling @code{realloc} or
+@code{reallocarray}.  These functions are declared in @file{stdlib.h}.
 @pindex stdlib.h
 
 @comment malloc.h stdlib.h
@@ -816,6 +816,21 @@  behavior, and will probably crash when @code{realloc} is passed a null
 pointer.
 @end deftypefun
 
+@comment malloc.h stdlib.h
+@comment BSD
+@deftypefun {void *} reallocarray (void *@var{ptr}, size_t @var{nmemb}, size_t @var{size})
+@safety{@prelim{}@mtsafe{}@asunsafe{@asulock{}}@acunsafe{@aculock{} @acsfd{} @acsmem{}}}
+
+The @code{reallocarray} function changes the size of the block whose address
+is @var{ptr} to be long enough to contain a vector of @var{nmemb} elements,
+each of size @var{size}.  It is equivalent to @samp{realloc (@var{ptr},
+@var{nmemb} * @var{size})}, except that @code{reallocarray} fails if the
+multiplication overflows.
+
+@code{reallocarray} should be used instead of @code{realloc} when the new size
+of the allocated block is the result of a multiplication that might overflow.
+@end deftypefun
+
 Like @code{malloc}, @code{realloc} may return a null pointer if no
 memory space is available to make the block bigger.  When this happens,
 the original block is untouched; it has not been modified or relocated.
@@ -1588,6 +1603,11 @@  Malloc}.
 Make a block previously allocated by @code{malloc} larger or smaller,
 possibly by copying it to a new location.  @xref{Changing Block Size}.
 
+@item void *reallocarray (void *@var{ptr}, size_t @var{nmemb}, size_t @var{size})
+Change the size of a block previously allocated by @code{malloc} to
+@code{@var{nmemb} * @var{size}} bytes as with @code{realloc}.  @xref{Changing
+Block Size}.
+
 @item void *calloc (size_t @var{count}, size_t @var{eltsize})
 Allocate a block of @var{count} * @var{eltsize} bytes using
 @code{malloc}, and set its contents to zero.  @xref{Allocating Cleared
diff --git a/stdlib/stdlib.h b/stdlib/stdlib.h
index 99125f2d23..428ca2ef68 100644
--- a/stdlib/stdlib.h
+++ b/stdlib/stdlib.h
@@ -422,6 +422,17 @@  extern void *calloc (size_t __nmemb, size_t __size)
    between objects pointed by the old and new pointers.  */
 extern void *realloc (void *__ptr, size_t __size)
      __THROW __attribute_warn_unused_result__;
+
+#ifdef __USE_GNU
+/* Re-allocate the previously allocated block in PTR, making the new
+   block large enough for NMEMB elements of SIZE bytes each.  */
+/* __attribute_malloc__ is not used, because if reallocarray returns
+   the same pointer that was passed to it, aliasing needs to be allowed
+   between objects pointed by the old and new pointers.  */
+extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)
+     __THROW __attribute_warn_unused_result__;
+#endif
+
 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 extern void free (void *__ptr) __THROW;
 
diff --git a/sysdeps/arm/nacl/libc.abilist b/sysdeps/arm/nacl/libc.abilist
index abd70c8108..b60bf7049a 100644
--- a/sysdeps/arm/nacl/libc.abilist
+++ b/sysdeps/arm/nacl/libc.abilist
@@ -1853,3 +1853,5 @@  GLIBC_2.25 gnu_dev_minor F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 58d768c6bc..a494c3947d 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2097,3 +2097,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 906050d2c3..2fc1a9bae7 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2008,6 +2008,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 66112dd0a7..4465a62ff1 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -98,6 +98,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 3ddadd2a24..96126d9e6a 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1862,6 +1862,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 977ab90bc7..aae351bbff 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2020,6 +2020,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index c7edb9a272..81ec65bec0 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1884,6 +1884,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 450be4e9c1..9db205b68e 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -99,6 +99,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 9e016bd76e..ee59e950b6 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1976,6 +1976,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 1a455be0f5..feb869757c 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2097,3 +2097,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 8eb5e668b9..a5b1c42929 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1951,6 +1951,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 416d9ac0ae..570a859aac 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1949,6 +1949,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index f4949e5a38..71008ad873 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1947,6 +1947,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index c7375aee3f..1a07d66caf 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1942,6 +1942,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 724a0e3a04..a62a41be62 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2138,3 +2138,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 2dc32b631c..f4f11dc625 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1980,6 +1980,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index 5658109ca2..2977569f2c 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1985,6 +1985,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
index c761221ffe..271d32e19b 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2185,3 +2185,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index 265c76914b..372ef67c27 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -99,6 +99,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 _Exit F
 GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index ed1b6bf26f..705ff851a9 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -1980,6 +1980,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 2e75d29e47..21fd2b5671 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1881,6 +1881,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index bd74c0cdab..313a71e589 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1866,6 +1866,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 5584838409..94a4fb2213 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1972,6 +1972,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index efedbe2874..6db5811c3f 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1910,6 +1910,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
index ffd988a33d..5d83926aac 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
@@ -2104,3 +2104,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
index f0c13ceea8..ce14ceb15f 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
@@ -2104,3 +2104,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
index ffd988a33d..5d83926aac 100644
--- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
@@ -2104,3 +2104,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index f57004c860..f69de7aa83 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1861,6 +1861,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 05629e17e7..a330855308 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2104,3 +2104,5 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 reallocarray F