diff --git a/meta/recipes-core/glibc/glibc/0040-CVE-2026-18374-01.patch b/meta/recipes-core/glibc/glibc/0040-CVE-2026-18374-01.patch new file mode 100644 index 00000000000..a5a71473ab2 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0040-CVE-2026-18374-01.patch @@ -0,0 +1,53 @@ +From f806c45178dbca3be08a25cc5dd6d5542ce84a59 Mon Sep 17 00:00:00 2001 +From: Dongkyun Son +Date: Fri, 4 Sep 2026 21:28:41 +0900 +Subject: [PATCH] libio: Fix CVE-2026-18374 heap buffer overflow in ccs= + handling + +When fopen() is called with a ,ccs= parameter whose value becomes empty +after strip(), the code must reject it with EINVAL instead of attempting +to use it. The original upstr() fallback could read past the ',' delimiter +and cause a heap buffer overflow. + +The fix checks if the charset specification is empty after strip() and +returns EINVAL immediately, preventing the overflow and following the +approach described in BZ #34574. + +CVE-2026-18374 - CVSS 4.9 (AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L) + +Reported-by: AISLE in partnership with Red Hat +Signed-off-by: Dongkyun Son +Reviewed-by: Florian Weimer +(cherry picked from commit 9765a538ebf8661a6e5578e01e35a3dd30db7eb4) + +CVE: CVE-2026-18374 +Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=f806c45178dbca3be08a25cc5dd6d5542ce84a59] +Signed-off-by: Peter Marko +--- + libio/fileops.c | 12 +++++++----- + 1 file changed, 7 insertions(+), 5 deletions(-) + +diff --git a/libio/fileops.c b/libio/fileops.c +index 775999deb3..18efe8e0c0 100644 +--- a/libio/fileops.c ++++ b/libio/fileops.c +@@ -305,12 +305,14 @@ _IO_new_file_fopen (FILE *fp, const char *filename, const char *mode, + *((char *) __mempcpy (ccs, cs + 5, endp - (cs + 5))) = '\0'; + strip (ccs, ccs); + +- if (__wcsmbs_named_conv (&fcts, ccs[2] == '\0' +- ? upstr (ccs, cs + 5) : ccs) != 0) ++ /* After stripping, ccs[2] == '\0' means the charset name is empty. ++ This is not a valid charset and would cause problems downstream. ++ Reject it with EINVAL (BZ #34574, CVE-2026-18374). */ ++ if (ccs[2] == '\0' || __wcsmbs_named_conv (&fcts, ccs) != 0) + { +- /* Something went wrong, we cannot load the conversion modules. +- This means we cannot proceed since the user explicitly asked +- for these. */ ++ /* Either the charset name is empty after strip(), or conversion ++ modules cannot be loaded. This means we cannot proceed since ++ the user explicitly asked for character conversion. */ + (void) _IO_file_close_it (fp); + free (ccs); + __set_errno (EINVAL); diff --git a/meta/recipes-core/glibc/glibc/0041-CVE-2026-18374-02.patch b/meta/recipes-core/glibc/glibc/0041-CVE-2026-18374-02.patch new file mode 100644 index 00000000000..d653d545f51 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0041-CVE-2026-18374-02.patch @@ -0,0 +1,103 @@ +From 5dd252cf1d113644b3679f5a158e9ef20217865e Mon Sep 17 00:00:00 2001 +From: Shamil Abdulaev +Date: Thu, 3 Sep 2026 20:19:42 +0300 +Subject: [PATCH] libio: Add test for fopen with an empty ", ccs=" value [BZ + #34574] + +This goes on top of the fix for CVE-2026-18374. The test runs the +reproducer from the bug report, plus "w,ccs=" and "w,ccs=,", and +expects NULL with errno set to EINVAL. + +Signed-off-by: Shamil Abdulaev +Reviewed-by: Florian Weimer +(cherry picked from commit cca93e5d88d3d4ed073c03100467696f652269e7) + +CVE: CVE-2026-18374 +Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=5dd252cf1d113644b3679f5a158e9ef20217865e] +Signed-off-by: Peter Marko +--- + libio/Makefile | 1 + + libio/tst-fopen-ccs-empty.c | 62 +++++++++++++++++++++++++++++++++++++ + 2 files changed, 63 insertions(+) + create mode 100644 libio/tst-fopen-ccs-empty.c + +diff --git a/libio/Makefile b/libio/Makefile +index 43ee8db06d..5b9929c3de 100644 +--- a/libio/Makefile ++++ b/libio/Makefile +@@ -99,6 +99,7 @@ tests = \ + tst-fgetc-after-eof \ + tst-fgetwc \ + tst-fgetws \ ++ tst-fopen-ccs-empty \ + tst-fopenloc2 \ + tst-fputws \ + tst-freopen \ +diff --git a/libio/tst-fopen-ccs-empty.c b/libio/tst-fopen-ccs-empty.c +new file mode 100644 +index 0000000000..64723965e1 +--- /dev/null ++++ b/libio/tst-fopen-ccs-empty.c +@@ -0,0 +1,62 @@ ++/* Test fopen with an empty ",ccs=" value in the mode string (bug 34574). ++ Copyright (C) 2026 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 ++ . */ ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++static void ++check_fopen_fails (const char *path, const char *mode) ++{ ++ errno = 0; ++ FILE *fp = fopen (path, mode); ++ TEST_VERIFY (fp == NULL); ++ TEST_COMPARE (errno, EINVAL); ++ if (fp != NULL) ++ fclose (fp); ++} ++ ++static int ++do_test (void) ++{ ++ char *path; ++ xclose (create_temp_file ("tst-fopen-ccs-empty", &path)); ++ ++ /* The value is blank and the mode string continues well past it. */ ++ enum { size = 1024 * 1024 }; ++ char *mode = xmalloc (size); ++ memset (mode, 'X', size); ++ mode[size - 1] = '\0'; ++ static const char prefix[] = "w,ccs= ,"; ++ memcpy (mode, prefix, sizeof (prefix) - 1); ++ check_fopen_fails (path, mode); ++ free (mode); ++ ++ check_fopen_fails (path, "w,ccs="); ++ check_fopen_fails (path, "w,ccs=,"); ++ ++ free (path); ++ return 0; ++} ++ ++#include diff --git a/meta/recipes-core/glibc/glibc_2.39.bb b/meta/recipes-core/glibc/glibc_2.39.bb index 144ce36ccc2..3e95792b359 100644 --- a/meta/recipes-core/glibc/glibc_2.39.bb +++ b/meta/recipes-core/glibc/glibc_2.39.bb @@ -72,6 +72,8 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \ file://0037-CVE-2026-77117.patch \ file://0038-CVE-2026-80489.patch \ file://0039-CVE-2026-77117-CVE-2026-80489.patch \ + file://0040-CVE-2026-18374-01.patch \ + file://0041-CVE-2026-18374-02.patch \ " S = "${WORKDIR}/git" B = "${WORKDIR}/build-${TARGET_SYS}"