From 24d4d38c0b32fd4eb075af89d7b744c5647db5c2 Mon Sep 17 00:00:00 2001 From: Han-Wen Nienhuys Date: Thu, 20 Jan 2022 15:12:01 +0000 Subject: reftable: fix resource leak in block.c error path Add test coverage for corrupt zlib data. Fix memory leaks demonstrated by unittest. This problem was discovered by a Coverity scan. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano --- reftable/block.c | 26 ++++++++++++------- reftable/reader.c | 23 ++++++++++------- reftable/readwrite_test.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 97 insertions(+), 18 deletions(-) (limited to 'reftable') diff --git a/reftable/block.c b/reftable/block.c index 855e3f5c94..6c8e870520 100644 --- a/reftable/block.c +++ b/reftable/block.c @@ -188,13 +188,16 @@ int block_reader_init(struct block_reader *br, struct reftable_block *block, uint32_t full_block_size = table_block_size; uint8_t typ = block->data[header_off]; uint32_t sz = get_be24(block->data + header_off + 1); - + int err = 0; uint16_t restart_count = 0; uint32_t restart_start = 0; uint8_t *restart_bytes = NULL; + uint8_t *uncompressed = NULL; - if (!reftable_is_block_type(typ)) - return REFTABLE_FORMAT_ERROR; + if (!reftable_is_block_type(typ)) { + err = REFTABLE_FORMAT_ERROR; + goto done; + } if (typ == BLOCK_TYPE_LOG) { int block_header_skip = 4 + header_off; @@ -203,7 +206,7 @@ int block_reader_init(struct block_reader *br, struct reftable_block *block, uLongf src_len = block->len - block_header_skip; /* Log blocks specify the *uncompressed* size in their header. */ - uint8_t *uncompressed = reftable_malloc(sz); + uncompressed = reftable_malloc(sz); /* Copy over the block header verbatim. It's not compressed. */ memcpy(uncompressed, block->data, block_header_skip); @@ -212,16 +215,19 @@ int block_reader_init(struct block_reader *br, struct reftable_block *block, if (Z_OK != uncompress2(uncompressed + block_header_skip, &dst_len, block->data + block_header_skip, &src_len)) { - reftable_free(uncompressed); - return REFTABLE_ZLIB_ERROR; + err = REFTABLE_ZLIB_ERROR; + goto done; } - if (dst_len + block_header_skip != sz) - return REFTABLE_FORMAT_ERROR; + if (dst_len + block_header_skip != sz) { + err = REFTABLE_FORMAT_ERROR; + goto done; + } /* We're done with the input data. */ reftable_block_done(block); block->data = uncompressed; + uncompressed = NULL; block->len = sz; block->source = malloc_block_source(); full_block_size = src_len + block_header_skip; @@ -251,7 +257,9 @@ int block_reader_init(struct block_reader *br, struct reftable_block *block, br->restart_count = restart_count; br->restart_bytes = restart_bytes; - return 0; +done: + reftable_free(uncompressed); + return err; } static uint32_t block_reader_restart_offset(struct block_reader *br, int i) diff --git a/reftable/reader.c b/reftable/reader.c index 006709a645..35781593a2 100644 --- a/reftable/reader.c +++ b/reftable/reader.c @@ -290,28 +290,33 @@ int reader_init_block_reader(struct reftable_reader *r, struct block_reader *br, err = reader_get_block(r, &block, next_off, guess_block_size); if (err < 0) - return err; + goto done; block_size = extract_block_size(block.data, &block_typ, next_off, r->version); - if (block_size < 0) - return block_size; - + if (block_size < 0) { + err = block_size; + goto done; + } if (want_typ != BLOCK_TYPE_ANY && block_typ != want_typ) { - reftable_block_done(&block); - return 1; + err = 1; + goto done; } if (block_size > guess_block_size) { reftable_block_done(&block); err = reader_get_block(r, &block, next_off, block_size); if (err < 0) { - return err; + goto done; } } - return block_reader_init(br, &block, header_off, r->block_size, - hash_size(r->hash_id)); + err = block_reader_init(br, &block, header_off, r->block_size, + hash_size(r->hash_id)); +done: + reftable_block_done(&block); + + return err; } static int table_iter_next_block(struct table_iter *dest, diff --git a/reftable/readwrite_test.c b/reftable/readwrite_test.c index 5f6bcc2f77..287cbc5999 100644 --- a/reftable/readwrite_test.c +++ b/reftable/readwrite_test.c @@ -254,6 +254,71 @@ static void test_log_write_read(void) reader_close(&rd); } +static void test_log_zlib_corruption(void) +{ + struct reftable_write_options opts = { + .block_size = 256, + }; + struct reftable_iterator it = { 0 }; + struct reftable_reader rd = { 0 }; + struct reftable_block_source source = { 0 }; + struct strbuf buf = STRBUF_INIT; + struct reftable_writer *w = + reftable_new_writer(&strbuf_add_void, &buf, &opts); + const struct reftable_stats *stats = NULL; + uint8_t hash1[GIT_SHA1_RAWSZ] = { 1 }; + uint8_t hash2[GIT_SHA1_RAWSZ] = { 2 }; + char message[100] = { 0 }; + int err, i, n; + + struct reftable_log_record log = { + .refname = "refname", + .value_type = REFTABLE_LOG_UPDATE, + .value = { + .update = { + .new_hash = hash1, + .old_hash = hash2, + .name = "My Name", + .email = "myname@invalid", + .message = message, + }, + }, + }; + + for (i = 0; i < sizeof(message) - 1; i++) + message[i] = (uint8_t)(rand() % 64 + ' '); + + reftable_writer_set_limits(w, 1, 1); + + err = reftable_writer_add_log(w, &log); + EXPECT_ERR(err); + + n = reftable_writer_close(w); + EXPECT(n == 0); + + stats = writer_stats(w); + EXPECT(stats->log_stats.blocks > 0); + reftable_writer_free(w); + w = NULL; + + /* corrupt the data. */ + buf.buf[50] ^= 0x99; + + block_source_from_strbuf(&source, &buf); + + err = init_reader(&rd, &source, "file.log"); + EXPECT_ERR(err); + + err = reftable_reader_seek_log(&rd, &it, "refname"); + EXPECT(err == REFTABLE_ZLIB_ERROR); + + reftable_iterator_destroy(&it); + + /* cleanup. */ + strbuf_release(&buf); + reader_close(&rd); +} + static void test_table_read_write_sequential(void) { char **names; @@ -633,6 +698,7 @@ static void test_corrupt_table(void) int readwrite_test_main(int argc, const char *argv[]) { + RUN_TEST(test_log_zlib_corruption); RUN_TEST(test_corrupt_table); RUN_TEST(test_corrupt_table_empty); RUN_TEST(test_log_write_read); -- cgit v1.2.3