glibc-2.42

[Joe Locash]

New minor version.

gcc-15.1.0 will FTBFS because the termio structure is being removed in glibc-2.42. Upstream fix for gcc:

​https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d32ece49d32b00448d967e7dbc6900fb25cbc775

[Bruce Dubbs]

Thanks Joe. I'll hold off with this until glibc-2.42 is actually released, but looking at the patches, I wonder if we can do the same thing by unsetting SANITIZER_GLIBC.

According to ​https://sourceware.org/glibc/wiki/Release/2.42, the new release should be in the next week.

[Douglas R. Reno]

After looking at this a bit, it also looks like we might need to update LLVM for this change too, since libsanitizer is part of llvm as well.

[Xi Ruoyao]

LLVM-20.1.8 already has the fix. I've not checked earlier versions but I'll update LLVM for BLFS soon.

For GCC we just need a simple sed: sed '/struct_termio_sz/d' -i libsanitizer/sanitizer_common/*

[Xi Ruoyao]

We may also want to pick the ​https://sourceware.org/bugzilla/show_bug.cgi?id=33227 fix. We don't enable -D FORTIFY_SOURCE by the book but if a user enables it (s)he may hit a FTBFS due to this issue.

[Xi Ruoyao]

Replying to Bruce Dubbs:

Thanks Joe. I'll hold off with this until glibc-2.42 is actually released, but looking at the patches, I wonder if we can do the same thing by unsetting SANITIZER_GLIBC.

There are more uses of SANITIZER_GLIBC like:

sanitizer_platform_limits_posix.cpp:#if SANITIZER_GLIBC || SANITIZER_ANDROID
sanitizer_platform_limits_posix.cpp-COMPILER_CHECK(sizeof(__sanitizer_struct_mallinfo) == sizeof(struct mallinfo));
sanitizer_platform_limits_posix.cpp-#endif

So disabling SANITIZER_GLIBC will disable too much things.

[Bruce Dubbs]

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.

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)

[Bruce Dubbs]

Fixed at commit 8641ff56b0.

[Douglas R. Reno]

SA-12.3-085 issued for glibc.