libc @ Savannah: The GNU C Library version 2.42 is now available

The GNU C Library

=================

The GNU C Library version 2.42 is now available.

The GNU C Library is used as the C library in the GNU system and

in GNU/Linux systems, as well as many other systems that use Linux

as the kernel.

The GNU C Library is primarily designed to be a portable

and high performance C library.  It follows all relevant

standards including ISO C23 and POSIX.1-2024.  It is also

internationalized and has one of the most complete

internationalization interfaces known.

The GNU C Library website is at http://www.gnu. ... /software/libc/

Packages for the 2.42 release may be downloaded from:

        http://ftpmirr ... .gnu.org/libc/

        http://ftp.gn ... org/gnu/libc/

The mirror list is at http://www.gnu. ... /order/ftp.html

Distributions are encouraged to track the release/* branches

corresponding to the releases they are using.  The release

branches will be updated with conservative bug fixes and new

features while retaining backwards compatibility.

NEWS for version 2.42

=====================

Major new features:

• The following ISO C23 function families (introduced in TS

  18661-4:2015) are now supported in <math.h>.  Each family includes

  functions for float, double, long double, _FloatN and _FloatNx, and a

  type-generic macro in <tgmath.h>.

  - Power and absolute-value functions: compoundn, pown, powr, rootn,

    rsqrt.

• On Linux, the pthread_gettid_np function has been added.

• The ISO C2Y family of unsigned abs functions, i.e. uabs, ulabs,

  ullabs, and uimaxabs, is now supported.

• On Linux, the <termios.h> interface now supports arbitrary baud rates;

  speed_t is redefined to simply be the baud rate specified as an

  unsigned int, which matches the kernel interface.

• The thread-local cache in malloc (tcache) now supports caching of

  large blocks.  This feature can be enabled by setting the tunable

  glibc.malloc.tcache_max to a larger value (max 4194304). Tcache is

  also significantly faster for small sizes.

• A new configure option, "--enable-sframe", can be used to enable

  SFrame support of the GNU C Libraries.  SFrame is a new stack trace

  information format which can be used by backtrace.  It requires

  binutils with a minimum version of 2.45.

• Support for lightweight stack guard pages via madvise and the

  MADV_GUARD_INSTALL flag has been added to pthread_create.

• Additional optimized and correctly rounded mathematical functions have

  been imported from the CORE-MATH project, in particular acospif,

  asinpif, atanpif, atan2pif, cospif, sinpif, tanpif.

• The testsuite has been significantly extended, including coverage of

  the functionality of the printf and scanf function families in many

  variants.

• The manual has been significantly extended and updated, particularly

  the threads, terminal, filesystem, resource, and math chapters.

• Code has been added to detect the x86-64 Intel Arrow Lake, Panther

  Lake, Clearwater Forest, and Diamond Rapids microarchitectures.

• Regarding S390, support for the new z17 platform has been added.

Deprecated and removed features, and other changes affecting compatibility:

• The glibc.rtld.execstack tunable now supports a compatibility mode to

  allow programs that require an executable stack through dynamically

  loaded shared libraries.

• On Linux, the <termio.h> header and the definition of struct termio

  in <sys/ioctl.h> have been removed. The termio interface has been

  obsolete since the very first version of POSIX.1 in 1988, replaced

  with <termios.h>.

• The support for TX lock elision of pthread mutexes has been deprecated

  on all architectures and will be removed in the next release.

• On AArch64 Linux targets supporting the Scalable Matrix Extension

  (SME), setjmp and sigsetjmp will disable the ZA state of SME.

Changes to build and runtime requirements:

• GCC 12.1 or later is now required to build the GNU C Library.

• GNU Binutils 2.39 or later is now required to build the GNU C Library.

Security related changes:

The following CVEs were fixed in this release, details of which can be

found in the advisories directory of the release tarball:

  GLIBC-SA-2025-0001:

    assert: Buffer overflow when printing assertion failure message

    (CVE-2025-0395)

  GLIBC-SA-2025-0003:

    power10: strcmp fails to save and restore nonvolatile vector

    registers (CVE-2025-5702)

  GLIBC-SA-2025-0004:

    power10: strncmp fails to save and restore nonvolatile vector

    registers (CVE-2025-5745)

  GLIBC-SA-2025-0005:

    posix: Fix double-free after allocation failure in regcomp

    (CVE-2025-8058)

The following bugs were resolved with this release:

  [5994] stdio: fflush after ungetc on seekable input stream

  [12724] stdio: fclose violates POSIX 2008 on seekable input streams

  [25263] dynamic-link: ldd and ld.so fail to resolve $ORIGIN with cross

    dir symlink

  [27880] nptl: Please provide a pthread pid accessor

  [29190] dynamic-link: Symbols with version hash zero lead to crashes,

    not matched correctly

  [29459] stdio: fwrite does not return EPIPE when underlying write

    fails with EPIPE.

  [31791] nss: [Regression] nss: memory for >8 elements in nsswitch.conf

    is not freed

  [32058] libc: qsort leaks memory if C++ exception is thrown from

    comparison function

  [32269] dynamic-link: RISC-V IFUNC resolver cannot access gp pointer

  [32369] stdio: fflush(NULL) doesn't properly flush files opened in

    read mode

  [32411] math: THREEp96 seems wrong

  [32412] dynamic-link: Initial DTV is reallocated using main realloc in

    auditing mode

  [32483] locale: ctype.h macros segfault in multithreaded programs with

    multiple libc.so

  [32529] stdio: fseek failure on file opened with "rm" mode after

    ungetc

  [32535] stdio: fflush failure on file opened with "rm" mode after

    ungetc

  [32541] libc: getenv cannot be overridden in static builds

  [32574] libc: pthread_attr_getstacksize/pthread_attr_getstack return

    incorrect main stack size

  [32612] dynamic-link: [aarch64 PAC] _dl_tlsdesc_dynamic can't be

    unwound through with _Unwind_Backtrace

  [32626] math: math: log10p1f is not correctly rounded

  [32627] math: math: sinhf is not correctly rounded

  [32630] math: math: tanf is not correctly rounded for all rounding

    modes

  [32653] dynamic-link: Review options for improving both security and

    backwards compatibility of glibc 2.41 dlopen / execstack handling

  [32694] math: wrong clang version 3.4 prereq checks in bits/floatn.h

    for __float128 support, should be 3.9

  [32708] libc: Inclusion of sys/mount.h triggers many gcc warnings

    using -Wshift-overflow=2 -Wsystem-headers

  [32711] math: math: remainder incorrect sign of zero result

  [32717] libc: glibc tests fail when bfd is built with --enable-error-

    execstack=yes

  [32723] math: [2.41 Regression] /usr/include/bits/floatn.h doesn't

    work with Intel SYCL compiler

  [32763] dynamic-link: Static PIE with more than one PT_LOAD segments

    at offset 0 segfault

  [32777] crypt: The performance of the rand() function degradation

  [32781] libc: Inccorect attribute access for sched_getattr

  [32782] nptl: Race conditions in pthread cancellation causing crash

  [32786] nptl: pthread_cond_* symbols should probably have had a

    version bump in 2.41

  [32795] nptl: aio_suspend_time64 confuses CLOCK_MONOTONIC and

    CLOCK_REALTIME

  [32810] dynamic-link: Immediate crash on x86-64 when running with

    GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVEC

  [32823] libc: make[2]: * [../Rules:248:

    /home/dave/gnu/glibc/objdir/elf/tst-origin] Error 1

  [32897] dynamic-link: pthread_getattr_np fails when executable stack

    tunable is set

  [32918] math: math: atanhf triggers UB

  [32919] math: math: coshf triggers UB

  [32920] math: math: logf triggers UB

  [32921] math: math: sinhf triggers UB

  [32922] math: math: cbrtf triggers UB

  [32923] math: math: cospif triggers UB

  [32924] math: math: erfcf triggers UB

  [32925] math: math: sinpif triggers UB

  [32932] libc: riscv: __riscv_hwprobe function attributes are incorrect

  [32947] libc: stdlib: wrong iovec array size on __libc_message_impl

  [32980] manual: getopt_long_only does not check long options first, as

    the manual claims

  [32981] ports: elf/tst-execstack-prog-static-tunable fails on

    sparc64-linux-gnu

  [32987] libc: New tst-dlopen-sgid test FAILs

  [32996] malloc: i386 TLS helper functions don't preserve XMM registers

  [33035] libc: [2.27 regression] Linux: __close_nocancel_nostatus

    clobbers errno

  [33056] string: Power 10 strcmp clobbers nonvolatile vector registers

    (CVE-2025-5702)

  [33059] string: Power 10 memchr clobbers v20

  [33060] string: Power 10 strncmp clobbers nonvolatile vector registers

    (CVE-2025-5745)

  [33088] dynamic-link: __ehdr_start may need run-time relocation

  [33089] build: [2.42 Regression] GCC 14.2.1 failed to build glibc

  [33134] libc: mcount_internal shouldn't use vector/r16-r31 registers

    nor call memcpy/memset

  [33139] stdio: %n after static dlopen is unreliable if file

    descriptors are exhausted

  [33165] build: [2.42 Regression] FAIL: elf/check-localplt

  [33173] math: Wrong IFUNC selector is used for modf/modff

  [33185] regex: Double-free after memory allocation failure in regcomp

    bracket expression parsing (CVE-2025-8058)

  [33224] dynamic-link: _dl_debug_state hook no longer works (since

    8329939a37f483a16013dd8af8303cbcb86d92cb)

Release Notes

=============

https://sourcewar ... wiki/Release/2.42

Contributors

============

This release was made possible by the contributions of many people.

The maintainers are grateful to everyone who has contributed

changes or bug reports.  These include:

Aaron Merey

Adhemerval Zanella

Andreas K. Hüttel

Andreas Schwab

Andrew Pinski

Arjun Shankar

Aurelien Jarno

Ben Kallus

Carlos O'Donell

Claudiu Zissulescu

Colin Ian King

Collin Funk

Cupertino Miranda

Cœur

DJ Delorie

David Lau

Dylan Fleming

Flavio Cruz

Florian Weimer

Frédéric Bérat

H. Peter Anvin

H.J. Lu

Jakub Jelinek

Jeremy Harris

Jitka Obselkova

John David Anglin

Jonathan Wakely

Joseph Myers

Julian Zhu

Lenard Mollenkopf

Luca Dariz

Luna Lamb

Maciej W. Rozycki

Mark Harris

Mark Wielaard

Martin Coufal

Matteo Croce

Michael Jeanson

Paul Zimmermann

Petr Malat

Pierre Blanchard

Radko Krkos

Ravina Jain

Ronan Pigott

Sachin Monga

Sam James

Samuel Thibault

Samuel Zeter

Sergei Zimmerman

Sergey Bugaev

Sergey Kolosov

Siddhesh Poyarekar

Stefan Liebler

Sunil K Pandey

Tobias Stoeckmann

Tomas Volf

Tulio Magno Quites Machado Filho

Wilco Dijkstra

William Hunt

Xi Ruoyao

YLK

Yangyu Chen

Yat Long Poon

Yury Khrustalev

Zhaoming Luo

gfleury

koraynilay

panzhe0328

zhenwei pi

наб

We would like to call out the following and thank them for their

tireless patch review:

Adhemerval Zanella

Andreas K. Hüttel

Andreas Schwab

Arjun Shankar

Carlos O'Donell

Collin Funk

Cupertino Miranda

DJ Delorie

Florian Weimer

Frédéric Bérat

Geoffrey Thomas

guoce

H.J. Lu

Joseph Myers

Maciej W. Rozycki

Mark Harris

Matthieu Longo

Palmer Dabbelt

Paul Eggert

Peter Bergner

Sachin Monga

Sam James

Samuel Thibault

Stefan Liebler

Sunil K Pandey

Tulio Magno Quites Machado Filho

Wilco Dijkstra

Yury Khrustalev

Source: Planet GNU