bsd-user: Fix possible memory leaks and wrong realloc call

These errors were reported by cppcheck:

[bsd-user/elfload.c:1108]: (error) Common realloc mistake: "syms" nulled but not freed upon failure
[bsd-user/elfload.c:1076]: (error) Memory leak: s
[bsd-user/elfload.c:1079]: (error) Memory leak: syms

v2:
* The previous fix for memory leaks was incomplete (thanks to Peter Maydell for te hint).
* Fix wrong realloc usage, too.

Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Stefan Weil 2011-01-16 16:28:20 +01:00 committed by Blue Swirl
parent 07d8a50cb0
commit 29718712eb

View File

@ -1044,7 +1044,7 @@ static void load_symbols(struct elfhdr *hdr, int fd)
struct elf_shdr sechdr, symtab, strtab;
char *strings;
struct syminfo *s;
struct elf_sym *syms;
struct elf_sym *syms, *new_syms;
lseek(fd, hdr->e_shoff, SEEK_SET);
for (i = 0; i < hdr->e_shnum; i++) {
@ -1072,15 +1072,24 @@ static void load_symbols(struct elfhdr *hdr, int fd)
/* Now know where the strtab and symtab are. Snarf them. */
s = malloc(sizeof(*s));
syms = malloc(symtab.sh_size);
if (!syms)
if (!syms) {
free(s);
return;
}
s->disas_strtab = strings = malloc(strtab.sh_size);
if (!s->disas_strtab)
if (!s->disas_strtab) {
free(s);
free(syms);
return;
}
lseek(fd, symtab.sh_offset, SEEK_SET);
if (read(fd, syms, symtab.sh_size) != symtab.sh_size)
if (read(fd, syms, symtab.sh_size) != symtab.sh_size) {
free(s);
free(syms);
free(strings);
return;
}
nsyms = symtab.sh_size / sizeof(struct elf_sym);
@ -1105,13 +1114,29 @@ static void load_symbols(struct elfhdr *hdr, int fd)
#endif
i++;
}
syms = realloc(syms, nsyms * sizeof(*syms));
/* Attempt to free the storage associated with the local symbols
that we threw away. Whether or not this has any effect on the
memory allocation depends on the malloc implementation and how
many symbols we managed to discard. */
new_syms = realloc(syms, nsyms * sizeof(*syms));
if (new_syms == NULL) {
free(s);
free(syms);
free(strings);
return;
}
syms = new_syms;
qsort(syms, nsyms, sizeof(*syms), symcmp);
lseek(fd, strtab.sh_offset, SEEK_SET);
if (read(fd, strings, strtab.sh_size) != strtab.sh_size)
if (read(fd, strings, strtab.sh_size) != strtab.sh_size) {
free(s);
free(syms);
free(strings);
return;
}
s->disas_num_syms = nsyms;
#if ELF_CLASS == ELFCLASS32
s->disas_symtab.elf32 = syms;