GNU C Library NEWS -- history of user-visible changes.
Copyright (C) 1992-2026 Free Software Foundation, Inc.
See the end for copying conditions.

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Version 2.43

Major new features:

* The ISO C23 free_sized, free_aligned_sized, memset_explicit, and
  memalignment functions have been added.

* As specified in ISO C23, the assert macro is defined to take variable
  arguments to support expressions with a comma inside a compound
  literal initializer not surrounded by parentheses.

* For ISO C23, the functions bsearch, memchr, strchr, strpbrk, strrchr,
  strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr that return
  pointers into their input arrays now have definitions as macros that
  return a pointer to a const-qualified type when the input argument is
  a pointer to a const-qualified type.

* The ISO C23 typedef names long_double_t, _Float32_t, _Float64_t, and
  (on platforms supporting _Float128) _Float128_t, introduced in TS
  18661-3:2015, have been added to <math.h>.

* The ISO C23 optional time bases TIME_MONOTONIC, TIME_ACTIVE, and
  TIME_THREAD_ACTIVE have been added.

* On Linux, the mseal function has been added.  It allows for sealing
  memory mappings to prevent further changes during process execution,
  such as changes to protection permissions, unmapping, relocation to
  another location, or shrinking the size.

* Additional optimized and correctly rounded mathematical functions have
  been imported from the CORE-MATH project, in particular acosh, asinh,
  atanh, erf, erfc, lgamma, and tgamma.

* Optimized implementations for fma, fmaf, remainder, remaindef, frexpf,
  frexp, frexpl (binary128), and frexpl (intel96) have been added.

* The SVID handling for acosf, acoshf, asinhf, atan2f, atanhf, coshf, fmodf,
  lgammaf/lgammaf_r, log10f, remainderf, sinhf, sqrtf, tgammaf, y0/j0,
  y1/j1, and yn/jn was moved to compat symbols, allowing improvements in
  performance.

* Experimental support for building with clang has been added.  It requires
  at least clang version 18, aarch64-linux-gnu or x86_64-linux-gnu
  targets, and a libgcc compatible runtime (including libgcc_s.so for
  pthread cancellation and backtrace runtime support).

* On Linux, the openat2 function has been added.  It is an extension of
  openat and provides a superset of its functionality.  It is supported only
  in LFS mode and is a cancellable entrypoint.

* On AArch64, support for 2MB transparent huge pages has been enabled by
  default in malloc (similar to setting glibc.malloc.hugetlb=1 tunable).

* On AArch64 Linux targets supporting the Scalable Matrix Extension
  (SME), the clone() system call wrapper will disable the ZA state of the
  SME.

* On AArch64 targets supporting the Branch Target Identification (BTI)
  extension, it is possible to enforce that all binaries in the process
  support BTI using the glibc.cpu.aarch64_bti tunable.

* On AArch64 Linux targets supporting at least one of the branch protection
  extensions (e.g. Branch Target Identification or Guarded Control Stack), it
  is possible to use LD_DEBUG=security to make the dynamic linker show
  warning messages about loaded binaries that do not support the
  corresponding security feature.

* On AArch64, vector variants of the new C23 exp2m1, exp10m1, log10p1,
  log2p1, and rsqrt routines have been added.

* On RISC-V, an RVV-optimized implementation of memset has been added.

* On x86, support for the Intel Nova Lake and Wildcat Lake processors
  has been added.

* The test suite has seen significant improvements in particular around
  the scanf, strerror, strsignal functions and multithreaded testing.

* Unicode support has been updated to Unicode 17.0.0.

* The manual has been updated and modernized, in particular also regarding
  many of its code examples.

Deprecated and removed features, and other changes affecting compatibility:

* Support for dumped heaps has been removed.  malloc_set_state() now always
  returns the error code -1.

* The aforementioned change in ISO C23 of the declaration of bsearch,
  memchr, strchr, strpbrk, strrchr, strstr, wcschr, wcspbrk, wcsrchr,
  wcsstr, and wmemchr as const-preserving macros can lead to compilation
  issues in code not set up for it. In particular, gnulib snapshots may need
  to be updated.

* The uimaxabs function has been renamed to umaxabs, following a change
  to the name of that function in ISO C2Y.  The old function continues
  to exist as a compatibility symbol for old binaries.

* The fromfp, fromfpx, ufromfp and ufromfpx functions, and the
  corresponding functions for other floating-point types, now return
  their result in the same type as their floating-point argument, rather
  than intmax_t or uintmax_t, in accordance with a change to the
  definition of these functions in ISO C23.  Existing binaries that use
  the versions returning intmax_t or uintmax_t will continue to work.

* The support for TX lock elision of pthread mutexes has been removed on all
  architectures (powerpc, s390x, x86_64).

* The next linux 6.19 release will remove support for compat syscalls on s390x.
  Therefore the s390-linux-gnu (31bit) configuration is deprecated in the
  glibc 2.43 release and will then be removed with glibc 2.44 release.
  Note that s390x-linux-gnu (64bit) remains supported.

Changes to build and runtime requirements:

* The LD_PROFILE functionality no longer has a default directory for the
  profile data it writes.  Instead, developers are required to set a
  directory explicitly using the LD_PROFILE_OUTPUT environment variable.
  To restore the previous, insecure behavior, processes can be run with
  LD_PROFILE_OUTPUT=/var/tmp.

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-2026-0001:
    Integer overflow in memalign leads to heap corruption
    (CVE-2026-0861)

  GLIBC-SA-2026-0002:
    getnetbyaddr and getnetbyaddr_r leak stack contents to DNS resovler
    (CVE-2026-0915)

  GLIBC-SA-2026-0003:
    wordexp with WRDE_REUSE and WRDE_APPEND may return uninitialized
    memory (CVE-2025-15281)

The following bugs were resolved with this release:

  [15503] math: [arm] Support ARM VFPv4 VFMA instruction in fma
  [20473] manual: Missing word in stack allocation documentation.
  [24657] manual: Two mistakes in manual index
  [25669] dynamic-link: Provide extra information when a found library
    file is not suitable
  [28038] stdio: getdelim()/getline() does not add NUL terminator if
    first character is EOF.
  [28267] nptl: nptl: pthread_exit should set cancellation type and
    state
  [28327] math: Wrong return type for {,u}fromfp{,x} functions
  [28376] libc: [meta] Build glibc with Clang
  [29326] math: Usage of double in sqrtf
  [30635] glob: stack-overflow /build/glibc-
    SzIz7B/glibc-2.31/posix/../posix/glob.c:546:9 in glob64
  [31470] libc: inttypes.h provides incorrect macro definitions
  [31664] libc: rfe: please provide openat2()
  [31943] dynamic-link: _dl_find_object can fail if ld.so contains gaps
    between load segments
  [32339] build: iconv functions do not follow symlinks
  [32378] libc: Implement memset_explicit
  [32583] libc: setup_vdso doesn't support two PT_LOAD segments if one
    of them has zero-vaddr
  [32994] libc: pthread_rwlock_init reinitialisation during calls to
    fork()
  [33093] manual: Typo in section 16.9.8 Out-of-Band Data of the manual
  [33129] dynamic-link: Need a version tag to indicate that glibc has
    working GNU2 TLS support
  [33182] build: Some tests leave random directories under /tmp
  [33190] localedata: localedata: Add en_SE for ISO8601 date and time
  [33212] dynamic-link: Add GLIBC_ABI_DT_X86_64_PLT version to indicate
    x86_64 psABI compliance for DT_X86_64_PLT* support
  [33221] dynamic-link: Add GLIBC_ABI_GNU_TLS version to indicate the
    working GNU TLS run-time
  [33227] network: namespace violation in inet-fortified.h
  [33234] libc: s390: Test tst-locale1 fails on s390 32-bit
  [33245] nptl: nptl: error in internal cancellation syscall handling,
    corrupting copy_file_range syscall return value
  [33254] libc: tst-freopen4-mem and tst-freopen64-4-mem FAIL
  [33286] build: Test failure with glibc built with -mno-direct-extern-
    access
  [33289] localedata: Update locale data to Unicode 17.0.0
  [33300] stdio: strip --strip-unneeded "breaks" libc.a (causing
    segfault in Rust programs linked libc statically)
  [33311] build: Testing failure with clang
  [33312] build: Disable -Wimplicit-fallthrough for clang
  [33318] build: -c shouldn't be passed to LIBC_TRY_TEST_CC_OPTION
  [33325] libc: ISO C2y renamed s/uimaxabs/umaxabs/
  [33340] libc: Possible regression in 2.42 termios refactoring re non-
    standard baud rate
  [33356] nptl: creating thread stack with guardsize 0 can erroneously
    conclude MADV_GUARD_INSTALL is available
  [33361] nss: Group merge does not handle ERANGE during merge
  [33376] build: GCC 16 fails to build glibc when configured with
    --disable-default-pie --enable-profile
  [33404] dynamic-link: ld.so crashes when compiled with -Os and
    configured with --enable-stack-protector=all
  [33405] math: Optimize modf/modff for x86_64-v2 aren't compiled with
    -fsignaling-nans
  [33411] math: powl() raises spurious overflow
  [33425] build: setfpucw.c:25:17: error: variable ‘cw’ set but not used
    [-Werror=unused-but-set-variable=]
  [33519] nss: getXXX API fails for turkish locale if nsswitch.conf
    contains "i"
  [33542] libc: x86: wmemset ifunc: stray '!' causing SSE2
  [33547] libc: microblaze: wrong __syscall_cancel_arch after
    89b53077d2a58f00e7debdfe58afabe953dac60d
  [33563] math: powf() fails for 0x1p+8192 ^ 1.0
  [33586] math: [2.43 Regression] FAIL: math/test-float64x-pow
  [33619] math: [2.43 Regression] Many math test failures on x86-64
  [33627] libc: execvp reads uninitialized memory
  [33632] nptl: Incorrect USE_64B_ATOMICS usage on struct new_sem
  [33653] time: __fts64_children_time64 Does Not Support 2038 Problem
  [33677] math: [2.43 Regression] Many math test failures
  [33715] nptl: nptl: pthread_create might act as a cancellation
    entrypoint
  [33717] nptl: nptl:
    pthread_join/pthread_timedjoin_np/pthread_clockjoin_np might not act
    as cancellation entrypoint
  [33752] manual: Doc incorrectly says double and long double may not be
    distinct
  [33814] glob: wordexp with WRDE_REUSE and WRDE_APPEND may return
    uninitialized memory

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)

Version 2.41

Major new features:

* Support for testing a glibc build with a set of C and C++ compilers
  different from the C and C++ compilers used to build glibc has been
  added:
  $ ../configure TEST_CC="gcc-6.4.1" TEST_CXX="g++-6.4.1"

  This includes support for testing the glibc build with Clang, e.g.,
  $ ../configure TEST_CC="clang" TEST_CXX="clang++"

  Some run-time failures with Clang are expected.

* The glibc test suite has been extended again significantly, with now
  6232 separate tests compared to 5408 in glibc-2.40.

* In /etc/resolv.conf and the RES_OPTIONS environment variable, option
  flags can now be prefixed with “-” to clear previously set flags.
  For example, if /etc/resolv.conf contains “options no-aaaa”, a
  process running with the RES_OPTIONS=-no-aaaa environment variable
  performs AAAA DNS queries when the glibc DNS stub resolver is used.

* The DNS stub resolver now supports the strict-error option.  If
  activated, getaddrinfo for the AF_UNSPEC address family (with dual
  A/AAAA DNS lookups) attemps to obtain an A/AAAA response pair from
  another DNS server if one of the responses indicates failure.  Without
  the strict-error option, getaddrinfo returns the A record data it has
  obtained even if the AAAA query failed.  The new strict error mode is
  incompatible with some DNS environments which do not follow the RFCs,
  which is why this mode is not enabled by default.  A future version
  of the library may turn it on by default, however.

* On Linux, the sched_setattr and sched_getattr functions have been
  added, for supporting parameterized scheduling policies such as
  SCHED_DEADLINE.

* The iconv program now supports converting files in place.  The program
  automatically uses a temporary file if required.

* Character encoding, character type info, and transliteration tables
  have been updated to Unicode 16.0.0.

* 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>.

  - Trigonometric functions: acospi, asinpi, atan2pi, atanpi, cospi,
    sinpi, tanpi.

* The GNU C Library now supports a feature test macro _ISOC2Y_SOURCE to
  enable features from the draft ISO C2Y standard.  Only some features
  from this draft standard are supported by the GNU C Library, and as
  the draft is under active development, the set of features enabled by
  this macro is liable to change.  Features from C2Y are also enabled
  by _GNU_SOURCE, or by compiling with "gcc -std=gnu2y".

* Optimized and correctly rounded exp10m1f, exp2m1f, expm1f, log10f,
  log2p1f, log1pf, log10p1f, cbrtf, erff, erfcf, lgammaf, tgammaf,
  tanf, acosf, acoshf, asinf, asinhf, atanf, atan2f, atanhf, coshf,
  sinhf, and tanhf functions have been added from the CORE-MATH
  project <https://core-math.gitlabpages.inria.fr/>.

* A benchtest framework is now in place to track the performance of many
  (mostly numerical) functions.

* A new tunable, glibc.rtld.execstack, can be used to control whether an
  executable stack is allowed from the main program, either implicitly
  due to a mising GNU_STACK ELF header or explicit explicitly because
  of the executable bit in GNU_STACK.  The default is to allow
  executable stacks.

* Support for the extensible rseq ABI introduced in the Linux kernel
  version 6.3 has been added.  The size and alignment of the rseq area
  is now determined by auxiliary vector entries when provided by the
  running kernel.  This results in __rseq_size now exposing features
  past the original ABI which currently include 'node_id' and 'mm_cid'
  and will also allow exposing new features as they get added to future
  Linux kernels.

* The GNU C Library now supports the Guarded Control Stack extension
  that allows to use shadow stacks on AArch64 systems that support this
  extension.  Building the library with standard branch protection
  enabled while using a toolchain that supports GCS (binutils 2.44 and
  GCC 15 or later) will enable GCS support in glibc.  There is no
  special configuration flag.  GCS-enabled glibc is compatible with all
  existing executables and shared libraries and will run with and
  without GCS support in the system.  GCS is opt-in and can be
  controlled at runtime via the glibc.cpu.aarch64_gcs tunable. By
  default GCS is disabled.  Linux kernel supports this since 6.13.

* Significant effort has been put into improving the code generation
  and speed of mathematical functions in the vector mathematics library
  on AArch64, with regard to the Scalable Vector Extension (SVE) and
  Advanced SIMD (Neon) intrinsics.

* Support for memory protection keys on AArch64 systems with enabled
  Stage 1 permission overlays feature as introduced in Armv8.9 / 9.4
  has been added.

* On PowerPC64, support for the return-oriented programming protection
  instructions added in ISA 3.1 (Power10) has been added, as well as
  function optimizations for Power10.

* A new architecture type has been introduced internally to better
  support Hygon x86-64 processors.

Deprecated and removed features, and other changes affecting
compatibility:

* abort is now async-signal-safe and its implementation makes longjmp
  from the SIGABRT handler always abort if set up with setjmp.  Use
  sigsetjmp to keep the old behavior, where the handler does not stop
  the process execution.

* dlopen and dlmopen no longer make the stack executable if a shared
  library requires it, either implicitly because of a missing GNU_STACK
  ELF header (and default ABI permission having the executable bit set)
  or explicitly because of the executable bit in GNU_STACK, and the
  stack is not already executable.  Instead, loading such objects will
  fail.

* The nios2*-*-linux-gnu configurations are no longer supported.

* The big-endian ARC port (arceb-linux-gnu) has been removed.

Changes to build and runtime requirements:

* On recent Linux kernels with vDSO getrandom support, getrandom does
  not act as a "shall occur" cancellation point, in which case it might
  not issue a syscall or trigger a deferred cancellation event.

* Testing the GNU C Library requires GNU awk to be compiled with support
  for high precision arithmetic via the MPFR 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)

The following bugs were resolved with this release:

  [6050] locale: iconv(1) buffers all of stdin in memory
  [10460] locale: iconv does not support in-place conversion
  [12683] nptl: Race conditions in pthread cancellation
  [14147] nptl: Async cancellation left active after longjmp out of
    signal handler
  [14799] network: RES_OPTIONS cannot disable options enabled in
    /etc/resolv.conf
  [17703] locale: iconv(1) EFAULTs reading the second non-mmapable input
  [20632] stdio: Buffer overflow in wchar IO (_IO_wfile_overflow)
  [23675] stdio: freopen() with "ccs=<charset>" leaves the stream
    unoriented
  [25847] nptl: pthread_cond_signal failed to wake up pthread_cond_wait
    due to a bug in undoing stealing
  [26275] libc: abort(3) is not signal-safe
  [27543] ports: Inconsistent behavior when handling FPSCR on SH
  [27821] stdio: double call to ungetc causes uninitialized memory
    reading. (also: ungetc causes memory leak)
  [29437] libc: arc4random is too slow
  [30009] build: unterminated options list in benchtest
  [30081] network: libresolv: timeout when running in single-request
    mode
  [30220] math: String to double returns incorrectly rounded value for
    hexadecimal subnormal
  [30584] libc: initstate and initstate_r crash when the state argument
    is unaligned
  [30647] stdio: scanf functions wrong on nan()
  [31394] libc: clone on sparc might fail with -EFAULT for no valid
    reason
  [31717] dynamic-link: TLS for library gets reallocated when loaded in
    two contexts.
  [31799] dynamic-link: -static-pie -Wl,-Ttext-segment=0x50000 doesn't
    work
  [31859] locale: Transliteration rules with two input characters like
    "ḌḌ" "DDH" do not work.
  [31890] network: DNS stub resolver ignores header-only error responses
  [31928] build: glibc doesn't compile if the compiler already define
    _FORTIFY_SOURCE
  [31968] libc: mremap implementation in C does not handle arguments
    correctly
  [31985] dynamic-link: la_objopen not called when ld.so is imported
    into a private namespace. However, la_objclose is called with an
    unknown cookie.
  [31997] libc: exit is not thread-safe, even when all atexit handlers
    are thread-safe
  [32026] libc: strerror, strsignal TLS not handled correctly for
    secondary namespaces (dlmopen, LD_AUDIT)
  [32033] locale: iconv (the program) does not truncate output file if
    input is empty
  [32040] nptl: CPU affinity test skeleton for sched_setaffinity and
    pthread_setaffinity_np can fail to report failure.
  [32042] build: Compilation issue for tst-resolv-short-response.c with
    older GCC
  [32045] math: nan() / strtod() incorrectly set errno for overflowing
    nan payload
  [32046] locale: iconv -c fails to report input encoding errors if
    output buffer is full
  [32047] libc: Tunables may incorrectly set Prefer_PMINUB_for_stringop
  [32050] locale: iconv - - < /dev/null fails with Bad file descriptor
  [32052] libc: stdlib.h's use of 'sz' identifier causes libstdc++ test
    failure
  [32065] dynamic-link: _dl_fini does not call la_objclose for proxy
    link maps
  [32066] dynamic-link: dlclose signals la_activity (LA_ACT_DELETE)
    after la_objclose calls
  [32078] string: Random __strchrnul_evex512 failures
  [32124] libc: readdir_r does not relay errors reported by the kernel
  [32125] libc: powerpc: Missing TOC stub in __syscall_cancel_arch for
    powerpc64le-linux-gnu
  [32126] libc: readdir64_r: Do not skip entries with zero d_ino values
  [32128] libc: Compat readdir64_r (__old_readdir64_r) does not enforce
    NAME_MAX limit
  [32134] stdio: freopen does not clear flags2 (FD_CLOEXEC etc)
  [32137] libc: libio/tst-stderr-compat, libio/tst-bz24228, math/test-
    matherr-2, nptl/tst-pthread_kill-exited fails on powerpc-unknown-
    linux-gnu
  [32140] stdio: freopen leaks memory on failure
  [32145] libc: New stdlib/tst-strtod1i, stdlib/tst-strtod3, stdlib/tst-
    strtod4, stdlib/tst-strtod5i failures on powerpc64le-linux-gnu
  [32148] stdio: Memory corruption with ancient i386 binaries using
    stdio
  [32168] localedata: Update locale data to Unicode 16.0.0
  [32173] libc: sparc: restartable syscalls are broken
  [32192] build: s390: utf16-utf32-z9.c fails to build w/ -fomit-frame-
    pointer
  [32197] locale: FAIL: iconv/tst-iconv_prog-buffer failures
  [32212] string: x86_64/strcmp caused 25% performance drop by commit
    84e7c46df
  [32214] libc: random_bits always returns the same value if getrandom
    fails
  [32215] libc: Signal handlers after fork may encounter missing robust
    mutex list
  [32228] libc: .preinit_array in /lib/riscv64-linux-gnu/Scrt1.o is not
    properly aligned
  [32231] dynamic-link: ldconfig auxcache format change in 2.36
  [32233] libc: error calls va_end twice.
  [32234] hurd: missing va_end call in fcntl.c
  [32245] build: glibc -Wstringop-overflow= build failure on hppa
  [32280] localedata: Enable transliteration rules with two input
    characters in scn_IT
  [32283] libc: Compilation issue for tst-syscall-restart.c with GCC
    10.2.1
  [32323] localedata: eo: Incorrect first day of week and first week of
    year
  [32344] string: Assembler warnings when building strcpy-evex.S and
    strncpy-evex.S
  [32350] hurd: function __xpg_strerror_r crashes for specific arguments
  [32360] stdio: Compilation issue for tst-printf-format-skeleton.c with
    GCC 10.2.1
  [32366] malloc: malloc test failures with GCC 15
  [32380] locale: dcigettext can cause SIGSEGV when domain name is too
    long
  [32414] libc: [x86_64 regression] tst-strtod5i.c:124:(.text+0x47c):
    undefined reference to `__copysignf128'
  [32418] math: __XXX math functions are declared, but not provided
  [32420] build: GCC 6 can't build glibc 2.41
  [32440] libc: getrandom() in glibc 2.41 (development) returns EINVAL
    as retcode instead of errno on powerpc64le
  [32448] libc: iconv reports failure with successful transliteration
  [32450] libc: system() does not return -1 if a child process can't be
    created
  [32465] nss: ./getaddrinfo.c:1884:11: error: variable 'endp' is used
    uninitialized whenever '||' condition is true [-Werror,-Wsometimes-
    uninitialized]
  [32470] dynamic-link: Integer truncation during x86-64 cache size
    computation
  [32488] libc: Glibc failed to build with CET enabled
  [32492] libc: New test failures
  [32494] build: Compilation issue with GCC 14.2.1
  [32508] dynamic-link: ldd: /lib/ld-linux.so.2: cannot execute binary
    file: Exec format error
  [32512] dynamic-link: failure to build on loong, undefined reference
    to `stpcpy'
  [32543] build: x32 glibc is miscompiled
  [32588] libc: [2.41 regression] bash crashes with 'realloc(): invalid
    pointer' with `env -i PATH=`

Version 2.40

Major new features:

* The <stdbit.h> header type-generic macros have been changed when using
  GCC 14.1 or later to use __builtin_stdc_bit_ceil etc. built-in functions
  in order to support unsigned __int128 and/or unsigned _BitInt(N) operands
  with arbitrary precisions when supported by the target.

* The GNU C Library now supports a feature test macro _ISOC23_SOURCE to
  enable features from the ISO C23 standard.  Only some features from
  this standard are supported by the GNU C Library.  The older name
  _ISOC2X_SOURCE is still supported.  Features from C23 are also enabled
  by _GNU_SOURCE, or by compiling with the GCC options -std=c23,
  -std=gnu23, -std=c2x or -std=gnu2x.

* 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>.

  - Exponential functions: exp2m1, exp10m1.

  - Logarithmic functions: log2p1, log10p1, logp1.

* A new tunable, glibc.rtld.enable_secure, can be used to run a program
  as if it were a setuid process. This is currently a testing tool to allow
  more extensive verification tests for AT_SECURE programs and not meant to
  be a security feature.

* On Linux, the epoll header was updated to include epoll ioctl definitions
  and the related structure added in Linux kernel 6.9.

* The fortify functionality has been significantly enhanced for building
  programs with clang against the GNU C Library.

* Many functions have been added to the vector library for aarch64:
    acosh, asinh, atanh, cbrt, cosh, erf, erfc, hypot, pow, sinh, tanh

* On x86, memset can now use non-temporal stores to improve the performance
  of large writes. This behaviour is controlled by a new tunable
  x86_memset_non_temporal_threshold.

Deprecated and removed features, and other changes affecting compatibility:

* Architectures which use a 32-bit seconds-since-epoch field in struct
  lastlog, struct utmp, struct utmpx (such as i386, powerpc64le, rv32,
  rv64, x86-64) switched from a signed to an unsigned type for that
  field.  This allows these fields to store timestamps beyond the year
  2038, until the year 2106.  Please note that applications are still
  expected to migrate off the interfaces declared in <utmp.h> and
  <utmpx.h> (except for login_tty) due to locking and session management
  problems.

* __rseq_size now denotes the size of the active rseq area (20 bytes
  initially), not the size of struct rseq (32 bytes initially).

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-2024-0004:
    ISO-2022-CN-EXT: fix out-of-bound writes when writing escape
    sequence (CVE-2024-2961)

  GLIBC-SA-2024-0005:
    nscd: Stack-based buffer overflow in netgroup cache (CVE-2024-33599)

  GLIBC-SA-2024-0006:
    nscd: Null pointer crash after notfound response (CVE-2024-33600)

  GLIBC-SA-2024-0007:
    nscd: netgroup cache may terminate daemon on memory allocation
    failure (CVE-2024-33601)

  GLIBC-SA-2024-0008:
    nscd: netgroup cache assumes NSS callback uses in-buffer strings
    (CVE-2024-33602)

The following bugs are resolved with this release:

  [19622] network: Support aliasing with struct sockaddr
  [21271] localedata: cv_RU: update translations
  [23774] localedata: lv_LV collates Y/y incorrectly
  [23865] string: wcsstr is quadratic-time
  [25119] localedata: Change Czech weekday names to lowercase
  [27777] stdio: fclose does a linear search, takes ages when many FILE*
    are opened
  [29770] libc: prctl does not match manual page ABI on powerpc64le-
    linux-gnu
  [29845] localedata: Update hr_HR locale currency to €
  [30701] time: getutxent misbehaves on 32-bit x86 when _TIME_BITS=64
  [31316] build: Fails test misc/tst-dirname "Didn't expect signal from
    child: got `Illegal instruction'" on non SSE CPUs
  [31317] dynamic-link: [RISCV] static PIE crashes during self
    relocation
  [31325] libc: mips: clone3 is wrong for o32
  [31335] math: Compile glibc with -march=x86-64-v3 should disable FMA4
    multi-arch version
  [31339] libc: arm32 loader crash after cleanup in 2.36
  [31340] manual: A bad sentence in section 22.3.5 (resource.texi)
  [31357] dynamic-link: $(objpfx)tst-rtld-list-diagnostics.out rule
    doesn't work with test wrapper
  [31370] localedata: wcwidth() does not treat
    DEFAULT_IGNORABLE_CODE_POINTs as zero-width
  [31371] dynamic-link: x86-64: APX and Tile registers aren't preserved
    in ld.so trampoline
  [31372] dynamic-link: _dl_tlsdesc_dynamic doesn't preserve all caller-
    saved registers
  [31383] libc: _FORTIFY_SOURCE=3 and __fortified_attr_access vs size of
    0 and zero size types
  [31385] build: sort-makefile-lines.py doesn't check variable with _
    nor with "^# variable"
  [31402] libc: clone (NULL, NULL, ...) clobbers %r7 register on
    s390{,x}
  [31405] libc: Improve dl_iterate_phdr using _dl_find_object
  [31411] localedata: Add Latgalian locale
  [31412] build: GCC 6 failed to build i386 glibc on Fedora 39
  [31429] build: Glibc failed to build with -march=x86-64-v3
  [31468] libc: sigisemptyset returns true when the set contains signals
    larger than 34
  [31476] network: Automatic activation of single-request options break
    resolv.conf reloading
  [31479] libc: Missing #include <sys/rseq.h> in sched_getcpu.c may
    result in a loss of rseq acceleration
  [31501] dynamic-link: _dl_tlsdesc_dynamic_xsavec may clobber %rbx
  [31518] manual: documentation: FLT_MAX_10_EXP questionable text, evtl.
    wrong,
  [31530] localedata: Locale file for Moksha - mdf_RU
  [31553] malloc: elf/tst-decorate-maps fails on ppc64el
  [31596] libc: On the llvm-arm32 platform, dlopen("not_exist.so", -1)
    triggers segmentation fault
  [31600] math: math: x86 ceill traps when FE_INEXACT is enabled
  [31601] math: math: x86 floor traps when FE_INEXACT is enabled
  [31603] math: math: x86 trunc traps when FE_INEXACT is enabled
  [31612] libc: arc4random fails to fallback to /dev/urandom if
    getrandom is not present
  [31629] build: powerpc64: Configuring with "--with-cpu=power10" and
    'CFLAGS=-O2 -mcpu=power9' fails to build glibc
  [31640] dynamic-link: POWER10 ld.so crashes in
    elf_machine_load_address with GCC 14
  [31661] libc: NPROCESSORS_CONF and NPROCESSORS_ONLN not available in
    getconf
  [31676] dynamic-link: Configuring with CC="gcc -march=x86-64-v3"
    --with-rtld-early-cflags=-march=x86-64 results in linker failure
  [31677] nscd: nscd: netgroup cache: invalid memcpy under low
    memory/storage conditions
  [31678] nscd: nscd: Null pointer dereferences after failed netgroup
    cache insertion
  [31679] nscd: nscd: netgroup cache may terminate daemon on memory
    allocation failure
  [31680] nscd: nscd: netgroup cache assumes NSS callback uses in-buffer
    strings
  [31682] math: [PowerPC] Floating point exception error for math test
    test-ceil-except-2 test-floor-except-2 test-trunc-except-2
  [31686] dynamic-link: Stack-based buffer overflow in
    parse_tunables_string
  [31695] libc: pidfd_spawn/pidfd_spawnp leak an fd if clone3 succeeds
    but execve fails
  [31719] dynamic-link: --enable-hardcoded-path-in-tests doesn't work
    with -Wl,--enable-new-dtags
  [31730] libc: backtrace_symbols_fd prints different strings than
    backtrace_symbols returns
  [31753] build: FAIL: link-static-libc with GCC 6/7/8
  [31755] libc: procutils_read_file doesn't start with a leading
    underscore
  [31756] libc: write_profiling is only in libc.a
  [31757] build: Should XXXf128_do_not_use functions be excluded?
  [31759] math: Extra nearbyint symbols in libm.a
  [31760] math: Missing math functions
  [31764] build: _res_opcodes should be a compat symbol only
  [31765] dynamic-link: _dl_mcount_wrapper is exported without prototype
  [31766] stdio: _IO_stderr_ _IO_stdin_ _IO_stdout should be compat
    symbols
  [31768] string: Extra stpncpy symbol in libc.a
  [31770] libc: clone3 is in libc.a
  [31774] libc: Missing __isnanf128 in libc.a
  [31775] math: Missing exp10 exp10f32x exp10f64 fmod fmodf fmodf32
    fmodf32x fmodf64 in libm.a
  [31777] string: Extra memchr strlen symbols in libc.a
  [31781] math: Missing math functions in libm.a
  [31782] build: Test build failure with recent GCC trunk (x86/tst-cpu-
    features-supports.c:69:3: error: parameter to builtin not valid:
    avx5124fmaps)
  [31785] string: loongarch: Extra strnlen symbols in libc.a
  [31786] string: powerpc: Extra strchrnul and strncasecmp_l symbols in
    libc.a
  [31787] math: powerpc: Extra llrintf, llrintf, llrintf32, and
    llrintf32 symbols in libc.a
  [31788] libc: microblaze: Extra cacheflush symbol in libc.a
  [31789] libc: powerpc: Extra versionsort symbol in libc.a
  [31790] libc: s390: Extra getutent32, getutent32_r, getutid32,
    getutid32_r, getutline32, getutline32_r, getutmp32, getutmpx32,
    getutxent32, getutxid32, getutxline32, pututline32, pututxline32,
    updwtmp32, updwtmpx32 in libc.a
  [31797] build: g++ -static requirement should be able to opt-out
  [31798] libc: pidfd_getpid.c is miscompiled by GCC 6.4
  [31802] time: difftime is pure not const
  [31808] time: The supported time_t range is not documented.
  [31840] stdio: Memory leak in _IO_new_fdopen (fdopen) on seek failure
  [31867] build: "CPU ISA level is lower than required" on SSE2-free
    CPUs
  [31876] time: "Date and time" documentation fixes for POSIX.1-2024 etc
  [31883] build: ISA level support configure check relies on bashism /
    is otherwise broken for arithmetic
  [31892] build: Always install mtrace.
  [31917] libc: clang mq_open fortify wrapper does not handle 4 argument
    correctly
  [31927] libc: clang open fortify wrapper does not handle argument
    correctly
  [31931] time: tzset may fault on very short TZ string
  [31934] string: wcsncmp crash on s390x on vlbb instruction
  [31963] stdio: Crash in _IO_link_in within __gcov_exit
  [31965] dynamic-link: rseq extension mechanism does not work as
    intended
  [31980] build: elf/tst-tunables-enable_secure-env fails on ppc

Version 2.39

Major new features:

* A new tunable, glibc.cpu.plt_rewrite, can be used to enable PLT
  rewrite on x86-64.  When enabled with non-lazy binding, the dynamic
  linker will rewrite indirect branches in PLT with direct branches.

* Sync with Linux kernel 6.6 shadow stack interface.  The --enable-cet
  configure option is only supported on x86-64.

* struct statvfs now has an f_type member, equal to the f_type statfs member;
  on the Hurd this was always available under a reserved name,
  and under Linux a spare has been allocated: it was always zero
  in previous versions of glibc, and zero is not a valid result.

* On Linux, the functions posix_spawnattr_getcgroup_np and
  posix_spawnattr_setcgroup_np have been added, along with the
  POSIX_SPAWN_SETCGROUP flag.  They allow posix_spawn and posix_spawnp
  to set the cgroupv2 in the new process in a race-free manner.  These
  functions are GNU extensions and require a kernel with clone3 support.

* On Linux, the pidfd_spawn and pidfd_spawp functions have been added.
  They have a similar prototype and semantic as posix_spawn, but instead of
  returning a process ID, they return a file descriptor that can be used
  along other pidfd functions (like pidfd_send_signal, poll, or waitid).
  The pidfd functionality avoids the issue of PID reuse with the traditional
  posix_spawn interface.

* On Linux, the pidfd_getpid function has been added.  It allows retrieving
  the process ID associated with the process file descriptor created by
  pid_spawn, fork_np, or pidfd_open.

* scanf-family functions now support the wN format length modifiers for
  arguments pointing to types intN_t, int_leastN_t, uintN_t or
  uint_leastN_t (for example, %w32d to read int32_t or int_least32_t in
  decimal, or %w32x to read uint32_t or uint_least32_t in hexadecimal)
  and the wfN format length modifiers for arguments pointing to types
  int_fastN_t or uint_fastN_t, as specified in draft ISO C2X.

* A new tunable, glibc.mem.decorate_maps, can be used to add additional
  information on underlying memory allocated by the glibc (for instance,
  on thread stack created by pthread_create or memory allocated by
  malloc).

* The <stdbit.h> header has been added from ISO C2X, with
  stdc_leading_zeros, stdc_leading_ones, stdc_trailing_zeros,
  stdc_trailing_ones, stdc_first_leading_zero, stdc_first_leading_one,
  stdc_first_trailing_zero, stdc_first_trailing_one, stdc_count_zeros,
  stdc_count_ones, stdc_has_single_bit, stdc_bit_width, stdc_bit_floor
  and stdc_bit_ceil function families, each having functions for
  unsigned char, unsigned short, unsigned int, unsigned long int and
  unsigned long long int, and a type-generic macro.

* On AArch64 new symbols were added to libmvec and now math.h has
  annotations to allow GCC 9 or newer to auto-vectorize calls to the
  following scalar math functions when -ffast-math is specified:
  acos, acosf, asin, asinf, atan, atanf, atan2, atan2f, cos, cosf,
  exp, expf, exp10, exp10f, exp2, exp2f, expm1, expm1f, log, logf,
  log10, log10f, log1p, log1pf, log2, log2f, sin, sinf, tan, tanf.

Deprecated and removed features, and other changes affecting compatibility:

* The ldconfig program now skips file names containing ';' or ending in
  ".dpkg.tmp" or ".dpkg.new", to avoid examining temporary files created
  by the RPM and dpkg package managers.

* libcrypt has been removed from the GNU C Library.  The configure
  options "--enable-crypt" and "--enable-nss-crypt" are no longer
  available.  <crypt.h>, libcrypt.a, and libcrypt.so.1 will not be
  installed.  For now <unistd.h> continues to declare the crypt
  function by default, to avoid introducing vulnerabilities into
  existing applications due to a missing prototype.  This declaration
  is deprecated and may be removed in a future glibc release.

  The replacement for libcrypt is libxcrypt, maintained separately from
  GNU libc, but available under compatible licensing terms, and providing
