Backport patch to fix CVE-2026-33845. References: https://nvd.nist.gov/vuln/detail/CVE-2026-33845
Upstream fix: https://gitlab.com/gnutls/gnutls/-/commit/e5b72c53c7d789d19d1d1cd10b275e87d0415413 Tested with ptest: Before: PASSED: 371, FAILED: 0, SKIPPED: 15 After: PASSED: 371, FAILED: 0, SKIPPED: 15 Signed-off-by: Adarsh Jagadish Kamini <[email protected]> --- .../gnutls/gnutls/CVE-2026-33845.patch | 195 ++++++++++++++++++ meta/recipes-support/gnutls/gnutls_3.8.12.bb | 1 + 2 files changed, 196 insertions(+) create mode 100644 meta/recipes-support/gnutls/gnutls/CVE-2026-33845.patch diff --git a/meta/recipes-support/gnutls/gnutls/CVE-2026-33845.patch b/meta/recipes-support/gnutls/gnutls/CVE-2026-33845.patch new file mode 100644 index 0000000000..d81ffb7ef7 --- /dev/null +++ b/meta/recipes-support/gnutls/gnutls/CVE-2026-33845.patch @@ -0,0 +1,195 @@ +From 9679a9c8ab1694b78c7cb285d29da904e3f3bc45 Mon Sep 17 00:00:00 2001 +From: Adarsh Jagadish Kamini <[email protected]> +Date: Mon, 27 Jul 2026 08:58:02 +0000 +Subject: [PATCH] buffers: switch from end_offset over to frag_length + +Instead of maintaining an inclusive [start_offset, end_offset] range +when reassembling DTLS handshake, +track start_offset and a relative frag_length instead. + +You'd think it'd be a no-op, but it fixes: + +* 0-length fragments triggering completion if message was 1 byte long +* a remotely triggerable underflow and an ensuing heap overrun + +Reported-by: Joshua Rogers of AISLE Research Team <[email protected]> +Fixes: #1811 +Fixes: CVE-2026-33845 +Fixes: GNUTLS-SA-2026-04-29-3 +CVSS: 7.5 High CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H +Signed-off-by: Alexander Sosedkin <[email protected]> + +CVE: CVE-2026-33845 +Upstream-Status: Backport [https://gitlab.com/gnutls/gnutls/-/commit/e5b72c53c7d789d19d1d1cd10b275e87d0415413] + +Backport notes: adapted to the stable branch, no logic changes. +- lib/buffers.c: the local fragment-size variable is named frag_size here, + not frag_length as upstream; renamed accordingly. +- lib/buffers.c: merge_handshake_packet() has no recv_buf alias in this + branch, so recv_buf[pos] was expanded to + session->internals.handshake_recv_buffer[pos], which changes line wrapping. +- lib/gnutls_int.h: applies cleanly. + +Assisted-by: kiro:claude-sonnet-4.6 +Signed-off-by: Adarsh Jagadish Kamini <[email protected]> +--- + lib/buffers.c | 57 ++++++++++++++++++++++++------------------------ + lib/gnutls_int.h | 4 ++-- + 2 files changed, 31 insertions(+), 30 deletions(-) + +diff --git a/lib/buffers.c b/lib/buffers.c +index 672380b05..2d77e7590 100644 +--- a/lib/buffers.c ++++ b/lib/buffers.c +@@ -923,10 +923,7 @@ static int parse_handshake_header(gnutls_session_t session, mbuffer_st *bufel, + } + data_size = _mbuffer_get_udata_size(bufel) - handshake_header_size; + +- if (frag_size > 0) +- hsk->end_offset = hsk->start_offset + frag_size - 1; +- else +- hsk->end_offset = 0; ++ hsk->frag_length = frag_size; + + _gnutls_handshake_log( + "HSK[%p]: %s (%u) was received. Length %d[%d], frag offset %d, frag length: %d, sequence: %d\n", +@@ -940,9 +937,10 @@ static int parse_handshake_header(gnutls_session_t session, mbuffer_st *bufel, + + if (hsk->length > 0 && + (frag_size > data_size || +- (frag_size > 0 && hsk->end_offset >= hsk->length))) { ++ (frag_size > 0 && hsk->start_offset + frag_size > hsk->length))) { + return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH); +- } else if (hsk->length == 0 && hsk->end_offset != 0 && ++ } else if (hsk->length == 0 && ++ hsk->start_offset + frag_size != hsk->start_offset && + hsk->start_offset != 0) + return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH); + +@@ -991,11 +989,10 @@ static int merge_handshake_packet(gnutls_session_t session, + hsk->data.length = hsk->length; + } + +- if (hsk->length > 0 && hsk->end_offset > 0 && +- hsk->end_offset - hsk->start_offset + 1 != hsk->length) { ++ if (hsk->length > 0 && hsk->frag_length > 0 && ++ hsk->frag_length != hsk->length) { + memmove(&hsk->data.data[hsk->start_offset], +- hsk->data.data, +- hsk->end_offset - hsk->start_offset + 1); ++ hsk->data.data, hsk->frag_length); + } + + session->internals.handshake_recv_buffer_size++; +@@ -1012,7 +1009,7 @@ static int merge_handshake_packet(gnutls_session_t session, + if (hsk->start_offset < + session->internals.handshake_recv_buffer[pos] + .start_offset && +- hsk->end_offset + 1 >= ++ hsk->start_offset + hsk->frag_length >= + session->internals.handshake_recv_buffer[pos] + .start_offset) { + memcpy(&session->internals.handshake_recv_buffer[pos] +@@ -1021,28 +1018,34 @@ static int merge_handshake_packet(gnutls_session_t session, + session->internals.handshake_recv_buffer[pos] + .start_offset = hsk->start_offset; + session->internals.handshake_recv_buffer[pos] +- .end_offset = MIN( +- hsk->end_offset, ++ .frag_length = MIN( ++ hsk->frag_length, + session->internals.handshake_recv_buffer[pos] +- .end_offset); +- } else if (hsk->end_offset > ++ .frag_length); ++ } else if (hsk->start_offset + hsk->frag_length > ++ session->internals.handshake_recv_buffer[pos] ++ .start_offset + + session->internals.handshake_recv_buffer[pos] +- .end_offset && ++ .frag_length && + hsk->start_offset <= + session->internals.handshake_recv_buffer[pos] +- .end_offset + +- 1) { ++ .start_offset + ++ session->internals.handshake_recv_buffer[pos] ++ .frag_length) { + memcpy(&session->internals.handshake_recv_buffer[pos] + .data.data[hsk->start_offset], + hsk->data.data, hsk->data.length); + +- session->internals.handshake_recv_buffer[pos] +- .end_offset = hsk->end_offset; + session->internals.handshake_recv_buffer[pos] + .start_offset = MIN( + hsk->start_offset, + session->internals.handshake_recv_buffer[pos] + .start_offset); ++ session->internals.handshake_recv_buffer[pos] ++ .frag_length = ++ hsk->start_offset + hsk->frag_length - ++ session->internals.handshake_recv_buffer[pos] ++ .start_offset; + } + _gnutls_handshake_buffer_clear(hsk); + } +@@ -1102,8 +1105,8 @@ static int get_last_packet(gnutls_session_t session, + } + + else if ((recv_buf[LAST_ELEMENT].start_offset == 0 && +- recv_buf[LAST_ELEMENT].end_offset == +- recv_buf[LAST_ELEMENT].length - 1) || ++ recv_buf[LAST_ELEMENT].frag_length == ++ recv_buf[LAST_ELEMENT].length) || + recv_buf[LAST_ELEMENT].length == 0) { + session->internals.dtls.hsk_read_seq++; + _gnutls_handshake_buffer_move(hsk, +@@ -1114,8 +1117,9 @@ static int get_last_packet(gnutls_session_t session, + /* if we don't have a complete handshake message, but we + * have queued data waiting, try again to reconstruct the + * handshake packet, using the queued */ +- if (recv_buf[LAST_ELEMENT].end_offset != +- recv_buf[LAST_ELEMENT].length - 1 && ++ if ((recv_buf[LAST_ELEMENT].start_offset + ++ recv_buf[LAST_ELEMENT].frag_length) != ++ recv_buf[LAST_ELEMENT].length && + record_check_unprocessed(session) > 0) + return gnutls_assert_val( + GNUTLS_E_INT_CHECK_AGAIN); +@@ -1302,9 +1306,7 @@ int _gnutls_parse_record_buffered_msgs(gnutls_session_t session) + &session->internals.record_buffer, + bufel, ret); + +- data_size = MIN(tmp.length, +- tmp.end_offset - +- tmp.start_offset + 1); ++ data_size = MIN(tmp.length, tmp.frag_length); + + ret = _gnutls_buffer_append_data( + &tmp.data, +@@ -1320,7 +1322,6 @@ int _gnutls_parse_record_buffered_msgs(gnutls_session_t session) + ret = merge_handshake_packet(session, &tmp); + if (ret < 0) + return gnutls_assert_val(ret); +- + } while (_mbuffer_get_udata_size(bufel) > 0); + + prev = bufel; +diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h +index 54d3c9f67..283f25c07 100644 +--- a/lib/gnutls_int.h ++++ b/lib/gnutls_int.h +@@ -479,10 +479,10 @@ typedef struct { + uint16_t sequence; + + /* indicate whether that message is complete. +- * complete means start_offset == 0 and end_offset == length ++ * complete means start_offset == 0 and frag_length == length + */ + uint32_t start_offset; +- uint32_t end_offset; ++ uint32_t frag_length; /* used exclusively in DTLS reassembly */ + + uint8_t header[MAX_HANDSHAKE_HEADER_SIZE]; + int header_size; diff --git a/meta/recipes-support/gnutls/gnutls_3.8.12.bb b/meta/recipes-support/gnutls/gnutls_3.8.12.bb index 468b4bdd40..4219a650de 100644 --- a/meta/recipes-support/gnutls/gnutls_3.8.12.bb +++ b/meta/recipes-support/gnutls/gnutls_3.8.12.bb @@ -25,6 +25,7 @@ SRC_URI = "https://www.gnupg.org/ftp/gcrypt/gnutls/v${SHRT_VER}/gnutls-${PV}.tar file://Add-ptest-support.patch \ file://c99.patch \ file://CVE-2026-3833.patch \ + file://CVE-2026-33845.patch \ " SRC_URI[sha256sum] = "a7b341421bfd459acf7a374ca4af3b9e06608dcd7bd792b2bf470bea012b8e51"
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