From eb5903a8e268ac4615f9f96a8254b0b72f585e07 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 28 Sep 2024 08:03:36 +0930 Subject: [PATCH] gas buffer overflow with --listing-rhs-width With listings enabled, gas keeps a small cache of source lines. They are stored in buffers of size LISTING_RHS_WIDTH, ie. 100. Given listing-rhs-width larger than 100 it is of course possible to overflow the buffer. Fix that by allocating as needed. We could allocate all buffers on the first call to print_source using listing_rhs_width, but I chose not to do that in case some future assembly directive allows changes to listing_rhs_width similarly to the way paper_width can change during assembly. --- gas/listing.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/gas/listing.c b/gas/listing.c index ef1798046e5..23f76a70ad7 100644 --- a/gas/listing.c +++ b/gas/listing.c @@ -1026,11 +1026,24 @@ list_symbol_table (void) typedef struct cached_line { - file_info_type * file; - unsigned int line; - char buffer [LISTING_RHS_WIDTH]; + file_info_type *file; + unsigned int line; + unsigned int bufsize; + char *buffer; } cached_line; +static void +alloc_cache (cached_line *cache, unsigned int width) +{ + if (cache->bufsize < width) + { + cache->bufsize = width; + free (cache->buffer); + cache->buffer = xmalloc (width); + } + cache->buffer[0] = 0; +} + static void print_source (file_info_type * current_file, list_info_type * list, @@ -1080,7 +1093,7 @@ print_source (file_info_type * current_file, cache->file = current_file; cache->line = list->hll_line; - cache->buffer[0] = 0; + alloc_cache (cache, width); rebuffer_line (current_file, cache->line, cache->buffer, width); } @@ -1101,7 +1114,7 @@ print_source (file_info_type * current_file, cache = cached_lines + next_free_line; cache->file = current_file; cache->line = current_file->linenum + 1; - cache->buffer[0] = 0; + alloc_cache (cache, width); p = buffer_line (current_file, cache->buffer, width); /* Cache optimization: If printing a group of lines -- 2.47.3