From be5c657ac0606ffc171d2a7a9902be8b2c398fd9 Mon Sep 17 00:00:00 2001 From: Mike Dalessio Date: Wed, 10 Feb 2021 09:24:04 -0500 Subject: [PATCH] fix: ensure add_incoming allocates the proper length memory Without this fix, valgrind reports for zero-length blocks: ==149294== Invalid write of size 4 ==149294== at 0x408121: add_incoming (ujit_core.c:173) ==149294== by 0x408121: gen_block_version (ujit_core.c:286) ==149294== by 0x40873C: gen_entry_point (ujit_core.c:303) ==149294== by 0x3609DF: rb_ujit_compile_iseq (ujit_iface.c:319) ==149294== by 0x33BD2F: mjit_exec (mjit.h:158) ==149294== by 0x33BD2F: rb_vm_exec (vm.c:2167) ... ==149294== Address 0x11278850 is 0 bytes inside a block of size 1 alloc'd ==149294== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so) ==149294== by 0x40811B: add_incoming (ujit_core.c:171) ==149294== by 0x40811B: gen_block_version (ujit_core.c:286) ==149294== by 0x40873C: gen_entry_point (ujit_core.c:303) ==149294== by 0x3609DF: rb_ujit_compile_iseq (ujit_iface.c:319) ==149294== by 0x33BD2F: mjit_exec (mjit.h:158) ==149294== by 0x33BD2F: rb_vm_exec (vm.c:2167) --- ujit_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ujit_core.c b/ujit_core.c index 7c0063c6816b8b..708a78ca969cdb 100644 --- a/ujit_core.c +++ b/ujit_core.c @@ -167,7 +167,7 @@ static void add_block_version(blockid_t blockid, block_t* block) static void add_incoming(block_t* p_block, uint32_t branch_idx) { // Add this branch to the list of incoming branches for the target - uint32_t* new_list = malloc(sizeof(uint32_t) * p_block->num_incoming + 1); + uint32_t* new_list = malloc(sizeof(uint32_t) * (p_block->num_incoming + 1)); memcpy(new_list, p_block->incoming, p_block->num_incoming); new_list[p_block->num_incoming] = branch_idx; p_block->incoming = new_list;