From 83788a36c646a1bdfba912267feab5db796a828e Mon Sep 17 00:00:00 2001 From: "J. Nick Koston" Date: Sun, 7 Jun 2026 00:33:03 -0500 Subject: [PATCH] [PR #12826/36df6c13 backport][3.14] Enforce max_line_size on fragmented request target and reason in C parser (#12837) CVE: CVE-2026-54277 Upstream-Status: Backport [https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d] Backport Changes: - Omitted generated `aiohttp/_http_parser.c` changes because the Scarthgap recipe regenerates that file from `_http_parser.pyx` during `do_configure`. - This fix depends on the max_line_size buffer logic introduced by CVE-2026-22815. Keep CVE-2026-22815.patch earlier in SRC_URI. (cherry picked from commit 5ab61bb4cd88f19b712f12c7c9295fe262bf804d) Signed-off-by: Darsh Kelaiya --- CHANGES/12826.bugfix.rst | 1 + aiohttp/_http_parser.pyx | 4 ++-- tests/test_http_parser.py | 22 ++++++++++++++++++++++ 3 files changed, 25 insertions(+), 2 deletions(-) create mode 100644 CHANGES/12826.bugfix.rst diff --git a/CHANGES/12826.bugfix.rst b/CHANGES/12826.bugfix.rst new file mode 100644 index 000000000..7e095615d --- /dev/null +++ b/CHANGES/12826.bugfix.rst @@ -0,0 +1 @@ +Fixed the C HTTP parser not enforcing ``max_line_size`` on a request target or response reason phrase that is split across multiple reads; each fragment was checked on its own, so an accumulated line could exceed the limit without raising ``LineTooLong``. The accumulated length is now checked, matching the pure-Python parser -- by :user:`bdraco`. diff --git a/aiohttp/_http_parser.pyx b/aiohttp/_http_parser.pyx index 8e9ecae69..01a0f859c 100644 --- a/aiohttp/_http_parser.pyx +++ b/aiohttp/_http_parser.pyx @@ -718,7 +718,7 @@ cdef int cb_on_url(cparser.llhttp_t* parser, const char *at, size_t length) except -1: cdef HttpParser pyparser = parser.data try: - if length > pyparser._max_line_size: + if len(pyparser._buf) + length > pyparser._max_line_size: status = pyparser._buf + at[:length] raise LineTooLong(status[:100] + b"...", pyparser._max_line_size) extend(pyparser._buf, at, length) @@ -733,7 +733,7 @@ cdef int cb_on_status(cparser.llhttp_t* parser, const char *at, size_t length) except -1: cdef HttpParser pyparser = parser.data try: - if length > pyparser._max_line_size: + if len(pyparser._buf) + length > pyparser._max_line_size: reason = pyparser._buf + at[:length] raise LineTooLong(reason[:100] + b"...", pyparser._max_line_size) extend(pyparser._buf, at, length) diff --git a/tests/test_http_parser.py b/tests/test_http_parser.py index 3e1f7dfaa..a724aae63 100644 --- a/tests/test_http_parser.py +++ b/tests/test_http_parser.py @@ -1161,6 +1161,17 @@ def test_http_request_max_status_line_under_limit(parser: HttpRequestParser) -> assert msg.url == URL("/path" + path.decode()) +def test_http_request_max_status_line_fragmented( + parser: HttpRequestParser, +) -> None: + # Split an overlong request target across reads so that each callback + # fragment is under the limit but the accumulated target is not. + match = "400, message:\n Got more than 8190 bytes when reading" + with pytest.raises(http_exceptions.LineTooLong, match=match): + parser.feed_data(b"GET /" + b"a" * 8000) + parser.feed_data(b"a" * 8000 + b" HTTP/1.1\r\nHost: a\r\n\r\n") + + def test_http_response_parser_utf8(response) -> None: text = "HTTP/1.1 200 Ok\r\nx-test:ั‚ะตัั‚\r\n\r\n".encode() @@ -1238,6 +1249,17 @@ def test_http_response_parser_status_line_under_limit( assert msg.reason == reason.decode() +def test_http_response_parser_status_line_too_long_fragmented( + response: HttpResponseParser, +) -> None: + # Split an overlong reason phrase across reads so that each callback + # fragment is under the limit but the accumulated reason is not. + match = "400, message:\n Got more than 8190 bytes when reading" + with pytest.raises(http_exceptions.LineTooLong, match=match): + response.feed_data(b"HTTP/1.1 200 " + b"a" * 8000) + response.feed_data(b"a" * 8000 + b"\r\n\r\n") + + def test_http_response_parser_bad_version(response) -> None: with pytest.raises(http_exceptions.BadHttpMessage): response.feed_data(b"HT/11 200 Ok\r\n\r\n") -- 2.35.6