From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 30 Nov 2020 18:37:46 +0000 (+0200)
Subject: lib-storage: Fix potential assert-crash when adding missing attachment flags
X-Git-Tag: 2.3.14.rc1~226
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=67b60270287a1ca184dd45ea4c90c71307d68072;p=thirdparty%2Fdovecot%2Fcore.git

lib-storage: Fix potential assert-crash when adding missing attachment flags

This happened only in a rather special condition. Added unit test to
reproduce it.

Fixes:
Panic: file index-mail-headers.c: line 298 (index_mail_parse_header): assertion failed: (part != NULL)
---

diff --git a/src/lib-storage/index/index-mail.c b/src/lib-storage/index/index-mail.c
index 61e6bfb3d8..a362942910 100644
--- a/src/lib-storage/index/index-mail.c
+++ b/src/lib-storage/index/index-mail.c
@@ -1412,11 +1412,18 @@ static int index_mail_parse_bodystructure(struct index_mail *mail,
 			/* we haven't parsed the header yet */
 			const char *reason =
 				index_mail_cache_reason(&mail->mail.mail, "bodystructure");
+			bool orig_bodystructure_header =
+				data->save_bodystructure_header;
+			bool orig_bodystructure_body =
+				data->save_bodystructure_body;
 			data->save_bodystructure_header = TRUE;
 			data->save_bodystructure_body = TRUE;
 			(void)get_cached_parts(mail);
 			if (index_mail_parse_headers(mail, NULL, reason) < 0) {
-				data->save_bodystructure_header = TRUE;
+				data->save_bodystructure_header =
+					orig_bodystructure_header;
+				data->save_bodystructure_body =
+					orig_bodystructure_body;
 				return -1;
 			}
 			i_assert(data->parser_ctx != NULL);
diff --git a/src/lib-storage/test-mail.c b/src/lib-storage/test-mail.c
index 4fa30a367b..8b799cece3 100644
--- a/src/lib-storage/test-mail.c
+++ b/src/lib-storage/test-mail.c
@@ -282,10 +282,23 @@ static void test_mail_random_fetch(struct mailbox *box, uint32_t seq)
 static void test_mail_random_access(void)
 {
 	struct test_mail_storage_ctx *ctx;
+	const char *const potential_never_cache_fields[] = {
+		"",
+		"flags",
+		"mime.parts",
+		"imap.body",
+		"imap.bodystructure",
+	};
+	unsigned int never_cache_field_idx =
+		i_rand_limit(N_ELEMENTS(potential_never_cache_fields));
+	const char *never_cache_fields =
+		potential_never_cache_fields[never_cache_field_idx];
 	struct test_mail_storage_settings set = {
 		.driver = "sdbox",
 		.extra_input = (const char *const[]) {
 			"mail_attachment_detection_options=add-flags",
+			t_strconcat("mail_never_cache_fields=",
+				    never_cache_fields, NULL),
 			NULL
 		},
 	};
@@ -294,6 +307,7 @@ static void test_mail_random_access(void)
 	test_begin("mail");
 	ctx = test_mail_storage_init();
 	test_mail_storage_init_user(ctx, &set);
+	e_debug(test_event, "mail_never_cache_fields=%s", never_cache_fields);
 	for (unsigned int i = 0; i < 20; i++) {
 		box = mailbox_alloc(ctx->user->namespaces->list, "INBOX", 0);
 		if (mailbox_open(box) < 0)
@@ -319,10 +333,71 @@ static void test_mail_random_access(void)
 	test_end();
 }
 
+static void test_attachment_flags_during_header_fetch(void)
+{
+	struct test_mail_storage_ctx *ctx;
+	struct test_mail_storage_settings set = {
+		.driver = "sdbox",
+		.extra_input = (const char *const[]) {
+			"mail_attachment_detection_options=add-flags",
+			"mail_never_cache_fields=mime.parts",
+			NULL
+		},
+	};
+
+	test_begin("mail attachment flags during header fetch");
+	ctx = test_mail_storage_init();
+	test_mail_storage_init_user(ctx, &set);
+
+	struct mailbox *box =
+		mailbox_alloc(ctx->user->namespaces->list, "INBOX", 0);
+	test_assert(mailbox_open(box) == 0);
+
+#define TEST_HDR_FROM "From: <test1@example.com>\r\n"
+	test_mail_save(box,
+		       TEST_HDR_FROM
+		       "\r\n"
+		       "test body\n");
+	/* Remove the $HasNoAttachment keyword */
+	test_mail_remove_keywords(box);
+
+	struct mailbox_transaction_context *trans =
+		mailbox_transaction_begin(box, 0, __func__);
+	struct mail *mail = mail_alloc(trans, 0, NULL);
+	mail_set_seq(mail, 1);
+
+	const char *from_headers[] = { "From", NULL };
+	struct mailbox_header_lookup_ctx *headers =
+		mailbox_header_lookup_init(box, from_headers);
+
+	struct istream *input;
+	const unsigned char *data;
+	size_t size;
+	test_assert(mail_get_header_stream(mail, headers, &input) == 0);
+	test_assert(i_stream_read_more(input, &data, &size) == 1);
+	/* TEST_HDR_FROM */
+	test_assert(size == strlen(TEST_HDR_FROM) &&
+		    memcmp(data, TEST_HDR_FROM, strlen(TEST_HDR_FROM)) == 0);
+	i_stream_skip(input, size);
+	test_assert(i_stream_read_more(input, &data, &size) == 1);
+	test_assert(size == 2 && memcmp(data, "\r\n", 2) == 0);
+	i_stream_skip(input, size);
+	test_assert(i_stream_read_more(input, &data, &size) == -1);
+
+	mailbox_header_lookup_unref(&headers);
+	mail_free(&mail);
+	test_assert(mailbox_transaction_commit(&trans) == 0);
+	mailbox_free(&box);
+	test_mail_storage_deinit_user(ctx);
+	test_mail_storage_deinit(&ctx);
+	test_end();
+}
+
 int main(int argc, char **argv)
 {
 	void (*const tests[])(void) = {
 		test_mail_random_access,
+		test_attachment_flags_during_header_fetch,
 		NULL
 	};
 	int ret;