apk: backport upstream fixes for unaligned access

On the kirkwood target, packages would frequently fail to install with
APKE_ADB_SCHEMA, APKE_ADB_BLOCK, and/or segfaults. The culprit was
unaligned access leading to bogus values being read out of memory on
these particular ARMv5 CPUs.

Pull in the relevant upstream fixes to address this.

Fixes: https://github.com/openwrt/openwrt/issues/21307
Link: https://gitlab.alpinelinux.org/alpine/apk-tools/-/merge_requests/391
Link: https://gitlab.alpinelinux.org/alpine/apk-tools/-/merge_requests/392
Signed-off-by: Matt Merhar <mattmerhar@protonmail.com>
Link: https://github.com/openwrt/openwrt/pull/21958
Signed-off-by: Robert Marko <robert.marko@sartura.hr>

package/system/apk/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=apk
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 
 PKG_SOURCE_URL=https://gitlab.alpinelinux.org/alpine/apk-tools.git
 PKG_SOURCE_PROTO:=git

package/system/apk/patches/0030-defines-align-apk_array.patch

@@ -0,0 +1,25 @@
+From fb856c4233202c489be5c6a2335da75bafab0a56 Mon Sep 17 00:00:00 2001
+From: Matt Merhar <mattmerhar@protonmail.com>
+Date: Tue, 3 Feb 2026 23:01:41 -0500
+Subject: [PATCH 1/4] defines: align apk_array
+
+-fsanitize=alignment complained about this one, though no issues were
+otherwise encountered during runtime.
+
+While x86-64 wants 8 byte alignment, 32-bit ARM hits SIGILL; so, use
+sizeof(void *) to tune it per target.
+---
+ src/apk_defines.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/src/apk_defines.h
++++ b/src/apk_defines.h
+@@ -178,7 +178,7 @@ struct apk_array {
+ 	uint32_t num;
+ 	uint32_t capacity : 31;
+ 	uint32_t allocated : 1;
+-};
++} __attribute__((aligned(sizeof(void *))));
+ 
+ extern const struct apk_array _apk_array_empty;
+ 

package/system/apk/patches/0031-defines-rework-apk_unaligned_-helpers.patch

@@ -0,0 +1,96 @@
+From 783fbbd591982749714fba784318bf0fac3c9d41 Mon Sep 17 00:00:00 2001
+From: Matt Merhar <mattmerhar@protonmail.com>
+Date: Tue, 3 Feb 2026 23:01:41 -0500
+Subject: [PATCH 2/4] defines: rework apk_unaligned_* helpers
+
+These only work properly on little endian input words, and
+apk_unaligned_u64a32 won't work correctly as-is on big endian systems.
+
+Change the suffixes to explicitly call out this "limitation" and switch
+the uint64_t variant to operate on single bytes as the others already do
+so it works as expected on big endian hosts.
+
+And, add a uint16_t variant.
+---
+ src/adb.c         |  2 +-
+ src/apk_defines.h | 22 ++++++++++++++++------
+ src/blob.c        |  2 +-
+ src/database.c    |  2 +-
+ 4 files changed, 19 insertions(+), 9 deletions(-)
+
+--- a/src/adb.c
++++ b/src/adb.c
+@@ -434,7 +434,7 @@ uint64_t adb_r_int(const struct adb *db,
+ 	case ADB_TYPE_INT_64:
+ 		ptr = adb_r_deref(db, v, 0, sizeof(uint64_t));
+ 		if (!ptr) return 0;
+-		return le64toh(apk_unaligned_u64a32(ptr));
++		return apk_unaligned_le64(ptr);
+ 	default:
+ 		return 0;
+ 	}
+--- a/src/apk_defines.h
++++ b/src/apk_defines.h
+@@ -151,24 +151,34 @@ static inline uint64_t apk_calc_installe
+ }
+ 
+ #if defined(__x86_64__) || defined(__i386__)
+-static inline uint32_t apk_unaligned_u32(const void *ptr)
++static inline uint16_t apk_unaligned_le16(const void *ptr)
++{
++	return *(const uint16_t *)ptr;
++}
++static inline uint32_t apk_unaligned_le32(const void *ptr)
+ {
+ 	return *(const uint32_t *)ptr;
+ }
+-static inline uint64_t apk_unaligned_u64a32(const void *ptr)
++static inline uint64_t apk_unaligned_le64(const void *ptr)
+ {
+ 	return *(const uint64_t *)ptr;
+ }
+ #else
+-static inline uint32_t apk_unaligned_u32(const void *ptr)
++static inline uint16_t apk_unaligned_le16(const void *ptr)
++{
++	const uint8_t *p = ptr;
++	return p[0] | (uint16_t)p[1] << 8;
++}
++static inline uint32_t apk_unaligned_le32(const void *ptr)
+ {
+ 	const uint8_t *p = ptr;
+ 	return p[0] | (uint32_t)p[1] << 8 | (uint32_t)p[2] << 16 | (uint32_t)p[3] << 24;
+ }
+-static inline uint64_t apk_unaligned_u64a32(const void *ptr)
++static inline uint64_t apk_unaligned_le64(const void *ptr)
+ {
+-	const uint32_t *p = ptr;
+-	return p[0] | (uint64_t)p[1] << 32;
++	const uint8_t *p = ptr;
++	return p[0] | (uint64_t)p[1] << 8 | (uint64_t)p[2] << 16 | (uint64_t)p[3] << 24 |
++		(uint64_t)p[4] << 32 | (uint64_t)p[5] << 40 | (uint64_t)p[6] << 48 | (uint64_t)p[7] << 56;
+ }
+ #endif
+ 
+--- a/src/blob.c
++++ b/src/blob.c
+@@ -98,7 +98,7 @@ static uint32_t murmur3_32(const void *p
+ 	int i;
+ 
+ 	for (i = 0; i < nblocks; i++, key += 4) {
+-		k  = apk_unaligned_u32(key);
++		k  = apk_unaligned_le32(key);
+ 		k *= c1;
+ 		k  = rotl32(k, 15);
+ 		k *= c2;
+--- a/src/database.c
++++ b/src/database.c
+@@ -90,7 +90,7 @@ static unsigned long csum_hash(apk_blob_
+ 	/* Checksum's highest bits have the most "randomness", use that
+ 	 * directly as hash */
+ 	if (csum.len >= sizeof(uint32_t))
+-		return apk_unaligned_u32(csum.ptr);
++		return apk_unaligned_le32(csum.ptr);
+ 	return 0;
+ }
+ 

package/system/apk/patches/0032-extract_v3-fix-unaligned-access-of-file-mode.patch

@@ -0,0 +1,33 @@
+From 98da5aa6b2539c28459f303fb06891df86a5b4c7 Mon Sep 17 00:00:00 2001
+From: Matt Merhar <mattmerhar@protonmail.com>
+Date: Tue, 3 Feb 2026 23:01:41 -0500
+Subject: [PATCH 3/4] extract_v3: fix unaligned access of file mode
+
+This is one of a couple places that frequently caused apk operations
+to mysteriously fail on the OpenWrt kirkwood target (ARMv5TE); in this
+particular case, APKE_ADB_SCHEMA would be returned.
+
+GDB showed the octal mode value being a nonsensical '022' whereas
+referencing the original memory showed the expected 0120000 (S_IFLNK):
+
+	(gdb) p/o *(uint16_t*)(target.ptr - 2)
+	$67 = 0120000
+	(gdb) p/o mode
+	$68 = 022
+
+So, utilize the newly added apk_unaligned_le16() to access it.
+---
+ src/extract_v3.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/src/extract_v3.c
++++ b/src/extract_v3.c
+@@ -73,7 +73,7 @@ static int apk_extract_v3_file(struct ap
+ 		uint16_t mode;
+ 
+ 		if (target.len < 2) goto err_schema;
+-		mode = le16toh(*(uint16_t*)target.ptr);
++		mode = apk_unaligned_le16(target.ptr);
+ 		target.ptr += 2;
+ 		target.len -= 2;
+ 		switch (mode) {

package/system/apk/patches/0033-io-synchronize-istream-buffer-alignment-with-file-of.patch

@@ -0,0 +1,240 @@
+From 2cb386c75518ca4df5348d1f29c75ac923fc847c Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
+Date: Thu, 5 Feb 2026 13:07:04 +0200
+Subject: [PATCH 4/4] io: synchronize istream buffer alignment with file
+ offset
+
+To correctly guarantee buffer alignment for apk_istream_get() reads
+the buffer needs to be aligned with the file offset. Fixup the
+io code to properly synchronize the alignment.
+
+This removes unaligned memory reads in various places. In practice
+this speeds up things and fixes the faults/read errors on platforms
+where unaligned access is an error.
+---
+ src/apk_io.h          |  3 ++-
+ src/io.c              | 37 +++++++++++++++++---------
+ src/io_gunzip.c       |  2 ++
+ src/io_url_libfetch.c |  2 ++
+ src/process.c         |  2 ++
+ test/unit/io_test.c   | 62 +++++++++++++++++++++++++++++++++++++++++++
+ 6 files changed, 94 insertions(+), 14 deletions(-)
+
+--- a/src/apk_io.h
++++ b/src/apk_io.h
+@@ -82,7 +82,7 @@ struct apk_istream {
+ 	unsigned int flags;
+ 	struct apk_progress *prog;
+ 	const struct apk_istream_ops *ops;
+-};
++} __attribute__((aligned(8)));
+ 
+ typedef int (*apk_archive_entry_parser)(void *ctx,
+ 					const struct apk_file_info *ae,
+@@ -144,6 +144,7 @@ struct apk_segment_istream {
+ 	struct apk_istream *pis;
+ 	uint64_t bytes_left;
+ 	time_t mtime;
++	uint8_t align;
+ };
+ struct apk_istream *apk_istream_segment(struct apk_segment_istream *sis, struct apk_istream *is, uint64_t len, time_t mtime);
+ 
+--- a/src/io.c
++++ b/src/io.c
+@@ -33,6 +33,9 @@
+ #define HAVE_O_TMPFILE
+ #endif
+ 
++// The granularity for the file offset and istream buffer alignment synchronization.
++#define APK_ISTREAM_ALIGN_SYNC 8
++
+ size_t apk_io_bufsize = 128*1024;
+ 
+ 
+@@ -111,16 +114,16 @@ ssize_t apk_istream_read_max(struct apk_
+ 		if (left > is->buf_size/4) {
+ 			r = is->ops->read(is, ptr, left);
+ 			if (r <= 0) break;
++			is->ptr = is->end = &is->buf[(is->ptr - is->buf + r) % APK_ISTREAM_ALIGN_SYNC];
+ 			left -= r;
+ 			ptr += r;
+ 			continue;
+ 		}
+ 
+-		r = is->ops->read(is, is->buf, is->buf_size);
++		r = is->ops->read(is, is->ptr, is->buf + is->buf_size - is->ptr);
+ 		if (r <= 0) break;
+ 
+-		is->ptr = is->buf;
+-		is->end = is->buf + r;
++		is->end = is->ptr + r;
+ 	}
+ 
+ 	if (r < 0) return apk_istream_error(is, r);
+@@ -136,19 +139,20 @@ int apk_istream_read(struct apk_istream
+ 
+ static int __apk_istream_fill(struct apk_istream *is)
+ {
+-	ssize_t sz;
+-
+ 	if (is->err) return is->err;
+ 
+-	if (is->ptr != is->buf) {
+-		sz = is->end - is->ptr;
+-		memmove(is->buf, is->ptr, sz);
+-		is->ptr = is->buf;
+-		is->end = is->buf + sz;
+-	} else if (is->end-is->ptr == is->buf_size)
+-		return -ENOBUFS;
++	size_t offs = is->ptr - is->buf;
++	if (offs >= APK_ISTREAM_ALIGN_SYNC) {
++		size_t buf_used = is->end - is->ptr;
++		uint8_t *ptr = &is->buf[offs % APK_ISTREAM_ALIGN_SYNC];
++		memmove(ptr, is->ptr, buf_used);
++		is->ptr = ptr;
++		is->end = ptr + buf_used;
++	} else {
++		if (is->end == is->buf+is->buf_size) return -ENOBUFS;
++	}
+ 
+-	sz = is->ops->read(is, is->end, is->buf + is->buf_size - is->end);
++	ssize_t sz = is->ops->read(is, is->end, is->buf + is->buf_size - is->end);
+ 	if (sz <= 0) return apk_istream_error(is, sz ?: 1);
+ 	is->end += sz;
+ 	return 0;
+@@ -282,6 +286,7 @@ static ssize_t segment_read(struct apk_i
+ 		if (r == 0) r = -ECONNABORTED;
+ 	} else {
+ 		sis->bytes_left -= r;
++		sis->align += r;
+ 	}
+ 	return r;
+ }
+@@ -290,6 +295,7 @@ static int segment_close(struct apk_istr
+ {
+ 	struct apk_segment_istream *sis = container_of(is, struct apk_segment_istream, is);
+ 
++	if (!sis->pis->ptr) sis->pis->ptr = sis->pis->end = &is->buf[sis->align % APK_ISTREAM_ALIGN_SYNC];
+ 	if (sis->bytes_left) apk_istream_skip(sis->pis, sis->bytes_left);
+ 	return is->err < 0 ? is->err : 0;
+ }
+@@ -316,6 +322,9 @@ struct apk_istream *apk_istream_segment(
+ 		sis->is.end = sis->is.ptr + len;
+ 		is->ptr += len;
+ 	} else {
++		// Calculated at segment_closet again, set to null to catch if
++		// the inner istream is used before segment close.
++		sis->align = is->end - is->buf;
+ 		is->ptr = is->end = 0;
+ 	}
+ 	sis->bytes_left -= sis->is.end - sis->is.ptr;
+@@ -600,6 +609,8 @@ struct apk_istream *apk_istream_from_fd(
+ 		.is.ops = &fd_istream_ops,
+ 		.is.buf = (uint8_t *)(fis + 1),
+ 		.is.buf_size = apk_io_bufsize,
++		.is.ptr = (uint8_t *)(fis + 1),
++		.is.end = (uint8_t *)(fis + 1),
+ 		.fd = fd,
+ 	};
+ 
+--- a/src/io_gunzip.c
++++ b/src/io_gunzip.c
+@@ -165,6 +165,8 @@ struct apk_istream *apk_istream_zlib(str
+ 		.is.ops = &gunzip_istream_ops,
+ 		.is.buf = (uint8_t*)(gis + 1),
+ 		.is.buf_size = apk_io_bufsize,
++		.is.ptr = (uint8_t*)(gis + 1),
++		.is.end = (uint8_t*)(gis + 1),
+ 		.zis = is,
+ 		.cb = cb,
+ 		.cbctx = ctx,
+--- a/src/io_url_libfetch.c
++++ b/src/io_url_libfetch.c
+@@ -161,6 +161,8 @@ struct apk_istream *apk_io_url_istream(c
+ 		.is.ops = &fetch_istream_ops,
+ 		.is.buf = (uint8_t*)(fis+1),
+ 		.is.buf_size = apk_io_bufsize,
++		.is.ptr = (uint8_t*)(fis+1),
++		.is.end = (uint8_t*)(fis+1),
+ 		.fetchIO = io,
+ 		.urlstat = fis->urlstat,
+ 	};
+--- a/src/process.c
++++ b/src/process.c
+@@ -317,6 +317,8 @@ struct apk_istream *apk_process_istream(
+ 		.is.ops = &process_istream_ops,
+ 		.is.buf = (uint8_t *)(pis + 1),
+ 		.is.buf_size = apk_io_bufsize,
++		.is.ptr = (uint8_t *)(pis + 1),
++		.is.end = (uint8_t *)(pis + 1),
+ 	};
+ 	r = apk_process_init(&pis->proc, apk_last_path_segment(argv[0]), logpfx, out, NULL);
+ 	if (r != 0) goto err;
+--- a/test/unit/io_test.c
++++ b/test/unit/io_test.c
+@@ -119,3 +119,65 @@ APK_TEST(io_foreach_config_file) {
+ 
+ 	assert_int_equal(0, apk_dir_foreach_config_file(MOCKFD, assert_path_entry, NULL, apk_filename_is_hidden, "a", "b", NULL));
+ }
++
++APK_TEST(io_istream_align) {
++	struct apk_istream *is = apk_istream_from_file(AT_FDCWD, "/dev/zero");
++	struct apk_segment_istream seg;
++	size_t bufsz = 1024*1024;
++	uint8_t *buf = malloc(bufsz), *ptr;
++
++	assert_int_equal(0, apk_istream_read(is, buf, 1024));
++
++	ptr = apk_istream_get(is, 1024);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	assert_ptr_ok(apk_istream_get(is, 7));
++	assert_ptr_ok(apk_istream_get(is, apk_io_bufsize - 1024));
++	assert_ptr_ok(apk_istream_get(is, 1));
++
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	assert_int_equal(0, apk_istream_read(is, buf, bufsz - 1));
++	assert_int_equal(0, apk_istream_read(is, buf, 1));
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	apk_istream_segment(&seg, is, 1024-1, 0);
++	apk_istream_close(&seg.is);
++	assert_ptr_ok(apk_istream_get(is, 1));
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	apk_istream_segment(&seg, is, bufsz-1, 0);
++	apk_istream_close(&seg.is);
++	assert_ptr_ok(apk_istream_get(is, 1));
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	assert_ptr_ok(apk_istream_get(is, 7));
++	apk_istream_segment(&seg, is, bufsz-7, 0);
++	assert_int_equal(0, apk_istream_read(&seg.is, buf, bufsz-10));
++	assert_int_equal(0, apk_istream_read(&seg.is, buf, 1));
++	apk_istream_close(&seg.is);
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	apk_istream_segment(&seg, is, bufsz*2+1, 0);
++	assert_int_equal(0, apk_istream_read(&seg.is, buf, bufsz));
++	assert_int_equal(0, apk_istream_read(&seg.is, buf, bufsz));
++	apk_istream_close(&seg.is);
++	assert_int_equal(0, apk_istream_read(is, buf, 7));
++	ptr = apk_istream_get(is, 64);
++	assert_ptr_ok(ptr);
++	assert_int_equal(0, (uintptr_t)ptr & 7);
++
++	apk_istream_close(is);
++	free(buf);
++}