[scarthgap][PATCH] Fix gnutls CVE-2026-33846

[scarthgap][PATCH] Fix gnutls CVE-2026-33846

[Roland Kovacs]

Backport patch [1] referenced in [2]. The difference in upstream and the backport
is skipping of intermediate patch [3] which essentially just aliases
`session->internals.handshake_recv_buffer -> recv_buf'.

NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33846

[1] https://gitlab.com/gnutls/gnutls/-/commit/65ab33fa54e34fba69d793735b7df3d383d1ff78
[2] https://security-tracker.debian.org/tracker/CVE-2026-33846
[3] https://gitlab.com/gnutls/gnutls/-/commit/9deffca528c23bbb218f5ec3bd4bb1bf4cbd1fc0

Signed-off-by: Roland Kovacs <roland.kovacs@est.tech>
---
 .../gnutls/gnutls/CVE-2026-33846.patch        | 66 +++++++++++++++++++
 meta/recipes-support/gnutls/gnutls_3.8.4.bb   |  1 +
 2 files changed, 67 insertions(+)
 create mode 100644 meta/recipes-support/gnutls/gnutls/CVE-2026-33846.patch

diff --git a/meta/recipes-support/gnutls/gnutls/CVE-2026-33846.patch b/meta/recipes-support/gnutls/gnutls/CVE-2026-33846.patch
new file mode 100644
index 0000000000..81c928c872
--- /dev/null
+++ b/meta/recipes-support/gnutls/gnutls/CVE-2026-33846.patch
@@ -0,0 +1,66 @@
+From f83c50305b4186075aeea26c7d8d64fdad95f381 Mon Sep 17 00:00:00 2001
+From: Alexander Sosedkin <asosedkin@redhat.com>
+Date: Fri, 17 Apr 2026 18:21:36 +0200
+Subject: [PATCH] buffers: add more checks to DTLS reassembly
+
+Previously, gnutls didn't check that DTLS fragments claimed
+a consistent message_length value.
+Additionally, a crucial array size check was missing,
+enabling an attacker to cause a heap overwrite.
+The updated version rejects fragments with mismatching length
+and adds a missing boundary check.
+
+Reported-by: Haruto Kimura (Stella)
+Reported-by: Oscar Reparaz
+Reported-by: Zou Dikai
+Fixes: #1816
+Fixes: #1838
+Fixes: #1839
+Fixes: CVE-2026-33846
+Fixes: GNUTLS-SA-2026-04-29-1
+CVSS: 7.4 High CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
+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 <asosedkin@redhat.com>
+
+CVE: CVE-2026-33846
+Upstream-Status: Backport [https://gitlab.com/gnutls/gnutls/-/commit/65ab33fa54e34fba69d793735b7df3d383d1ff78]
+Signed-off-by: Roland Kovacs <roland.kovacs@est.tech>
+---
+ lib/buffers.c | 21 +++++++++++++++++++++
+ 1 file changed, 21 insertions(+)
+
+diff --git a/lib/buffers.c b/lib/buffers.c
+index 672380b05..2934fd366 100644
+--- a/lib/buffers.c
++++ b/lib/buffers.c
+@@ -1009,6 +1009,27 @@ static int merge_handshake_packet(gnutls_session_t session,
+ 			&session->internals.handshake_recv_buffer[pos], hsk);
+ 
+ 	} else {
++		if (hsk->length !=
++			session->internals.handshake_recv_buffer[pos].length) {
++			/* inconsistent across fragments */
++			_gnutls_handshake_buffer_clear(hsk);
++			return gnutls_assert_val(
++				GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
++		}
++		/* start_offset + data.length <= hsk->length <= max_length */
++		if (hsk->length < hsk->start_offset + hsk->data.length) {
++			/* impossible claims, overflow requested */
++			_gnutls_handshake_buffer_clear(hsk);
++			return gnutls_assert_val(
++				GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
++		}
++		if (hsk->length >
++			session->internals.handshake_recv_buffer[pos].data.max_length) {
++			/* we don't have this much allocated, overflow guard */
++			_gnutls_handshake_buffer_clear(hsk);
++			return gnutls_assert_val(
++				GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
++		}
+ 		if (hsk->start_offset <
+ 			    session->internals.handshake_recv_buffer[pos]
+ 				    .start_offset &&
+-- 
+2.47.3
+
diff --git a/meta/recipes-support/gnutls/gnutls_3.8.4.bb b/meta/recipes-support/gnutls/gnutls_3.8.4.bb
index d27d2cfa74..92f302cd88 100644
--- a/meta/recipes-support/gnutls/gnutls_3.8.4.bb
+++ b/meta/recipes-support/gnutls/gnutls_3.8.4.bb
@@ -45,6 +45,7 @@ SRC_URI = "https://www.gnupg.org/ftp/gcrypt/gnutls/v${SHRT_VER}/gnutls-${PV}.tar
            file://CVE-2025-14831-9.patch \
            file://CVE-2026-42009_p1.patch \
            file://CVE-2026-42009_p2.patch \
+           file://CVE-2026-33846.patch \
            "
 
 SRC_URI[sha256sum] = "2bea4e154794f3f00180fa2a5c51fe8b005ac7a31cd58bd44cdfa7f36ebc3a9b"
-- 
2.43.0

Patchtest results for [scarthgap][PATCH] Fix gnutls CVE-2026-33846

[patchtest]

[-- Attachment #1: Type: text/plain, Size: 3076 bytes --]

Thank you for your submission. Patchtest identified one
or more issues with the patch. Please see the log below for
more information:

---
Testing patch /home/patchtest/share/mboxes/scarthgap-Fix-gnutls-CVE-2026-33846.patch

FAIL: test shortlog format: Commit shortlog (first line of commit message) should follow the format "<target>: <summary>" (test_mbox.TestMbox.test_shortlog_format)

PASS: test CVE check ignore (test_metadata.TestMetadata.test_cve_check_ignore)
PASS: test CVE tag format (test_patch.TestPatch.test_cve_tag_format)
PASS: test Signed-off-by presence (test_mbox.TestMbox.test_signed_off_by_presence)
PASS: test Signed-off-by presence (test_patch.TestPatch.test_signed_off_by_presence)
PASS: test Upstream-Status presence (test_patch.TestPatch.test_upstream_status_presence_format)
PASS: test auh changelog truncation notice (test_mbox.TestMbox.test_auh_changelog_truncation_notice)
PASS: test author valid (test_mbox.TestMbox.test_author_valid)
PASS: test commit message presence (test_mbox.TestMbox.test_commit_message_presence)
PASS: test commit message user tags (test_mbox.TestMbox.test_commit_message_user_tags)
PASS: test lic files chksum modified not mentioned (test_metadata.TestMetadata.test_lic_files_chksum_modified_not_mentioned)
PASS: test max line length (test_metadata.TestMetadata.test_max_line_length)
PASS: test mbox format (test_mbox.TestMbox.test_mbox_format)
PASS: test non-AUH upgrade (test_mbox.TestMbox.test_non_auh_upgrade)
PASS: test shortlog length (test_mbox.TestMbox.test_shortlog_length)
PASS: test target mailing list (test_mbox.TestMbox.test_target_mailing_list)

SKIP: pretest pylint: No python related patches, skipping test (test_python_pylint.PyLint.pretest_pylint)
SKIP: pretest src uri left files: Patch cannot be merged (test_metadata.TestMetadata.pretest_src_uri_left_files)
SKIP: test bugzilla entry format: No bug ID found (test_mbox.TestMbox.test_bugzilla_entry_format)
SKIP: test lic files chksum presence: No added recipes, skipping test (test_metadata.TestMetadata.test_lic_files_chksum_presence)
SKIP: test license presence: No added recipes, skipping test (test_metadata.TestMetadata.test_license_presence)
SKIP: test pylint: No python related patches, skipping test (test_python_pylint.PyLint.test_pylint)
SKIP: test series merge on head: Merge test is disabled for now (test_mbox.TestMbox.test_series_merge_on_head)
SKIP: test src uri left files: Patch cannot be merged (test_metadata.TestMetadata.test_src_uri_left_files)
SKIP: test summary presence: No added recipes, skipping test (test_metadata.TestMetadata.test_summary_presence)

---

Please address the issues identified and
submit a new revision of the patch, or alternatively, reply to this
email with an explanation of why the patch should be accepted. If you
believe these results are due to an error in patchtest, please submit a
bug at https://bugzilla.yoctoproject.org/ (use the 'Patchtest' category
under 'Yocto Project Subprojects'). For more information on specific
failures, see: https://wiki.yoctoproject.org/wiki/Patchtest. Thank
you!

Re: [OE-core] Patchtest results for [scarthgap][PATCH] Fix gnutls CVE-2026-33846

[Roland Kovács]

On Thu, 2026-08-20 at 14:31 +0000, Patchtest via lists.openembedded.org wrote:
> Thank you for your submission. Patchtest identified one
> or more issues with the patch. Please see the log below for
> more information:
> 
> ---
> Testing patch /home/patchtest/share/mboxes/scarthgap-Fix-gnutls-CVE-2026-33846.patch
> 
> FAIL: test shortlog format: Commit shortlog (first line of commit message) should follow the
> format "<target>: <summary>" (test_mbox.TestMbox.test_shortlog_format)
> 
> PASS: test CVE check ignore (test_metadata.TestMetadata.test_cve_check_ignore)
> PASS: test CVE tag format (test_patch.TestPatch.test_cve_tag_format)
> PASS: test Signed-off-by presence (test_mbox.TestMbox.test_signed_off_by_presence)
> PASS: test Signed-off-by presence (test_patch.TestPatch.test_signed_off_by_presence)
> PASS: test Upstream-Status presence (test_patch.TestPatch.test_upstream_status_presence_format)
> PASS: test auh changelog truncation notice
> (test_mbox.TestMbox.test_auh_changelog_truncation_notice)
> PASS: test author valid (test_mbox.TestMbox.test_author_valid)
> PASS: test commit message presence (test_mbox.TestMbox.test_commit_message_presence)
> PASS: test commit message user tags (test_mbox.TestMbox.test_commit_message_user_tags)
> PASS: test lic files chksum modified not mentioned
> (test_metadata.TestMetadata.test_lic_files_chksum_modified_not_mentioned)
> PASS: test max line length (test_metadata.TestMetadata.test_max_line_length)
> PASS: test mbox format (test_mbox.TestMbox.test_mbox_format)
> PASS: test non-AUH upgrade (test_mbox.TestMbox.test_non_auh_upgrade)
> PASS: test shortlog length (test_mbox.TestMbox.test_shortlog_length)
> PASS: test target mailing list (test_mbox.TestMbox.test_target_mailing_list)
> 
> SKIP: pretest pylint: No python related patches, skipping test
> (test_python_pylint.PyLint.pretest_pylint)
> SKIP: pretest src uri left files: Patch cannot be merged
> (test_metadata.TestMetadata.pretest_src_uri_left_files)
> SKIP: test bugzilla entry format: No bug ID found (test_mbox.TestMbox.test_bugzilla_entry_format)
> SKIP: test lic files chksum presence: No added recipes, skipping test
> (test_metadata.TestMetadata.test_lic_files_chksum_presence)
> SKIP: test license presence: No added recipes, skipping test
> (test_metadata.TestMetadata.test_license_presence)
> SKIP: test pylint: No python related patches, skipping test
> (test_python_pylint.PyLint.test_pylint)
> SKIP: test series merge on head: Merge test is disabled for now
> (test_mbox.TestMbox.test_series_merge_on_head)
> SKIP: test src uri left files: Patch cannot be merged
> (test_metadata.TestMetadata.test_src_uri_left_files)
> SKIP: test summary presence: No added recipes, skipping test
> (test_metadata.TestMetadata.test_summary_presence)
> 
> ---
> 
> Please address the issues identified and
> submit a new revision of the patch, or alternatively, reply to this
> email with an explanation of why the patch should be accepted. If you
> believe these results are due to an error in patchtest, please submit a
> bug at https://bugzilla.yoctoproject.org/ (use the 'Patchtest' category
> under 'Yocto Project Subprojects'). For more information on specific
> failures, see: https://wiki.yoctoproject.org/wiki/Patchtest. Thank
> you!
> 
> -=-=-=-=-=-=-=-=-=-=-=-
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> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [roland.kovacs@est.tech]
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My bad! I'll re-send the patch with correct subject line.

Cheers,
	Roland