musl: patch CVE-2025-26519

Details: https://nvd.nist.gov/vuln/detail/CVE-2025-26519

Pick the patches that are attached to the musl advisory:
https://www.openwall.com/lists/musl/2025/02/13/1

(From OE-Core rev: bbdd7d54b070f62f13967df8a13f5f14f2c36120)

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-core/musl/musl/CVE-2025-26519-1.patch

@@ -0,0 +1,39 @@
+From 8ebb2a68dfac02e7a83885587a9a5a203147ebbe Mon Sep 17 00:00:00 2001
+From: Rich Felker <dalias@aerifal.cx>
+Date: Wed, 19 Nov 2025 13:23:38 +0100
+Subject: [PATCH] iconv: fix erroneous input validation in EUC-KR decoder
+
+as a result of incorrect bounds checking on the lead byte being
+decoded, certain invalid inputs which should produce an encoding
+error, such as "\xc8\x41", instead produced out-of-bounds loads from
+the ksc table.
+
+in a worst case, the loaded value may not be a valid unicode scalar
+value, in which case, if the output encoding was UTF-8, wctomb would
+return (size_t)-1, causing an overflow in the output pointer and
+remaining buffer size which could clobber memory outside of the output
+buffer.
+
+bug report was submitted in private by Nick Wellnhofer on account of
+potential security implications.
+
+CVE: CVE-2025-26519
+Upstream-Status: Backport [https://git.musl-libc.org/cgit/musl/commit/?id=e5adcd97b5196e29991b524237381a0202a60659]
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+---
+ src/locale/iconv.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/locale/iconv.c b/src/locale/iconv.c
+index 3047c27b..1fb66bc8 100644
+--- a/src/locale/iconv.c
++++ b/src/locale/iconv.c
+@@ -495,7 +495,7 @@ size_t iconv(iconv_t cd, char **restrict in, size_t *restrict inb, char **restri
+ 			if (c >= 93 || d >= 94) {
+ 				c += (0xa1-0x81);
+ 				d += 0xa1;
+-				if (c >= 93 || c>=0xc6-0x81 && d>0x52)
++				if (c > 0xc6-0x81 || c==0xc6-0x81 && d>0x52)
+ 					goto ilseq;
+ 				if (d-'A'<26) d = d-'A';
+ 				else if (d-'a'<26) d = d-'a'+26;

meta/recipes-core/musl/musl/CVE-2025-26519-2.patch

@@ -0,0 +1,38 @@
+From 7e7052e17e900194a588d337ff4a8e646133afed Mon Sep 17 00:00:00 2001
+From: Rich Felker <dalias@aerifal.cx>
+Date: Wed, 19 Nov 2025 13:27:15 +0100
+Subject: [PATCH] iconv: harden UTF-8 output code path against input decoder
+ bugs
+
+the UTF-8 output code was written assuming an invariant that iconv's
+decoders only emit valid Unicode Scalar Values which wctomb can encode
+successfully, thereby always returning a value between 1 and 4.
+
+if this invariant is not satisfied, wctomb returns (size_t)-1, and the
+subsequent adjustments to the output buffer pointer and remaining
+output byte count overflow, moving the output position backwards,
+potentially past the beginning of the buffer, without storing any
+bytes.
+
+CVE: CVE-2025-26519
+Upstream-Status: Backport [https://git.musl-libc.org/cgit/musl/commit/?id=c47ad25ea3b484e10326f933e927c0bc8cded3da]
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+---
+ src/locale/iconv.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/locale/iconv.c b/src/locale/iconv.c
+index 1fb66bc8..fb1d3217 100644
+--- a/src/locale/iconv.c
++++ b/src/locale/iconv.c
+@@ -538,6 +538,10 @@ size_t iconv(iconv_t cd, char **restrict in, size_t *restrict inb, char **restri
+ 				if (*outb < k) goto toobig;
+ 				memcpy(*out, tmp, k);
+ 			} else k = wctomb_utf8(*out, c);
++			/* This failure condition should be unreachable, but
++			 * is included to prevent decoder bugs from translating
++			 * into advancement outside the output buffer range. */
++			if (k>4) goto ilseq;
+ 			*out += k;
+ 			*outb -= k;
+ 			break;

meta/recipes-core/musl/musl_git.bb

@@ -14,7 +14,9 @@ SRC_URI = "git://git.etalabs.net/git/musl;branch=master;protocol=https \
            file://0001-Make-dynamic-linker-a-relative-symlink-to-libc.patch \
            file://0002-ldso-Use-syslibdir-and-libdir-as-default-pathes-to-l.patch \
            file://0003-elf.h-add-typedefs-for-Elf64_Relr-and-Elf32_Relr.patch \
-          "
+           file://CVE-2025-26519-1.patch \
+           file://CVE-2025-26519-2.patch \
+           "
 
 S = "${WORKDIR}/git"