From 322b071c45d5e5ae14d247e8fa74a4cff58e1a8a Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 10 Oct 2023 18:16:38 +1030 Subject: [PATCH] asan: invalid free in bfd_init_section_compress_status With specially crafted compressed sections, it's possible to tickle a problem when decompressing: If the compression headers says the uncompressed size is zero, this will be seen as an error return from bfd_compress_section_contents. On errors the caller should free any malloc'd input buffers, but this isn't really an error and the section contents have been updated to a bfd_alloc'd buffer which can't be freed. * compress.c (bfd_compress_section_contents): Return -1 as error rather than 0. (bfd_init_section_compress_status, bfd_compress_section): Adjust. --- bfd/compress.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/bfd/compress.c b/bfd/compress.c index 83564fea15f..7ec7b0edf38 100644 --- a/bfd/compress.c +++ b/bfd/compress.c @@ -558,7 +558,7 @@ decompress_contents (bool is_zstd, bfd_byte *compressed_buffer, field was allocated using bfd_malloc() or equivalent. Return the uncompressed size if the full section contents is - compressed successfully. Otherwise return 0. */ + compressed successfully. Otherwise return (bfd_size_type) -1. */ static bfd_size_type bfd_compress_section_contents (bfd *abfd, sec_ptr sec) @@ -610,7 +610,7 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec) buffer_size = uncompressed_size; buffer = bfd_malloc (buffer_size); if (buffer == NULL) - return 0; + return (bfd_size_type) -1; if (!decompress_contents (ch_type == ch_compress_zstd, input_buffer + orig_header_size, @@ -618,7 +618,7 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec) { bfd_set_error (bfd_error_bad_value); free (buffer); - return 0; + return (bfd_size_type) -1; } free (input_buffer); bfd_set_section_alignment (sec, uncompressed_alignment_pow); @@ -636,7 +636,7 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec) buffer_size = compressed_size; buffer = bfd_alloc (abfd, buffer_size); if (buffer == NULL) - return 0; + return (bfd_size_type) -1; if (update) { @@ -659,7 +659,7 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec) { bfd_release (abfd, buffer); bfd_set_error (bfd_error_bad_value); - return 0; + return (bfd_size_type) -1; } #endif } @@ -669,7 +669,7 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec) { bfd_release (abfd, buffer); bfd_set_error (bfd_error_bad_value); - return 0; + return (bfd_size_type) -1; } compressed_size += new_header_size; @@ -1087,7 +1087,7 @@ bfd_init_section_compress_status (bfd *abfd, sec_ptr sec) } sec->contents = uncompressed_buffer; - if (bfd_compress_section_contents (abfd, sec) == 0) + if (bfd_compress_section_contents (abfd, sec) == (bfd_size_type) -1) { free (sec->contents); sec->contents = NULL; @@ -1130,7 +1130,7 @@ bfd_compress_section (bfd *abfd, sec_ptr sec, bfd_byte *uncompressed_buffer) } sec->contents = uncompressed_buffer; - if (bfd_compress_section_contents (abfd, sec) == 0) + if (bfd_compress_section_contents (abfd, sec) == (bfd_size_type) -1) { free (sec->contents); sec->contents = NULL; -- 2.30.2