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Fix #1: Segmentation fault when using NOBITS sections #2

Merged
mhu merged 3 commits from fix-segmentation-fault into master 2023-01-04 15:11:49 +01:00
Conversation 0 Commits 3 Files Changed 2 +19 -20
2 changed files with 19 additions and 20 deletions
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32
src/elfpatch.c
View File

@ -232,9 +232,6 @@ static int elf_patch_update_info(elfpatch_handle_t *ep)
{ {
Elf_Kind ek; Elf_Kind ek;
const char *type_string = "unrecognized"; const char *type_string = "unrecognized";
size_t header_count = 0ull;
GElf_Phdr phdr;
size_t i;
ret_val_if_ep_err(ep, -1001); ret_val_if_ep_err(ep, -1001);
@ -276,20 +273,6 @@ static int elf_patch_update_info(elfpatch_handle_t *ep)
return -1; return -1;
} }
/* Get program headers */
if ( elf_getphdrnum(ep->elf, &header_count) != 0) {
print_err("Error reading count of program headers: %s\n", elf_errmsg(-1));
return -1;
}
for (i = 0ull; i < header_count; i++) {
if (gelf_getphdr(ep->elf, (int)i, &phdr) != &phdr) {
print_err("Error reading program header (%zu): %s\n", i, elf_errmsg(-1));
return -1;
}
print_debug("Read program header %zu\n", i);
}
return 0; return 0;
} }
@ -440,8 +423,16 @@ int elf_patch_compute_crc_over_section(elfpatch_handle_t *ep, const char *sectio
} }
print_debug("Section data length: %lu\n", data->d_size); print_debug("Section data length: %lu\n", data->d_size);
if (!data->d_size) if (!data->d_size) {
print_err("Section %s contains no data.\n", section); print_err("Section %s contains no data.\n", section);
return -2;
}
/* NOBIT sections have a length but no data in the file. Abort in this case */
if (!data->d_buf) {
print_err("Section %s does not contain loadable data.\n", section);
return -2;
}
/* If big endian or granularity is byte, simply compute CRC. No reordering is necessary */ /* If big endian or granularity is byte, simply compute CRC. No reordering is necessary */
if (!little_endian || granularity == GRANULARITY_BYTE) { if (!little_endian || granularity == GRANULARITY_BYTE) {
@ -543,6 +534,11 @@ int elf_patch_write_crcs_to_section(elfpatch_handle_t *ep, const char *section,
/* Get data object of section */ /* Get data object of section */
output_sec_data = elf_getdata(output_section->scn, NULL); output_sec_data = elf_getdata(output_section->scn, NULL);
sec_bytes = (uint8_t *)output_sec_data->d_buf; sec_bytes = (uint8_t *)output_sec_data->d_buf;
if (!sec_bytes) {
print_err("Output section '%s' does not contain loadable data. It has to be allocated in the ELF file\n",
section);
goto ret_err;
}
/* Check the start and end magics */ /* Check the start and end magics */
if (check_start_magic) { if (check_start_magic) {

7
src/main.c
View File

@ -407,12 +407,14 @@ int main(int argc, char **argv)
/* Check if all sections are present */ /* Check if all sections are present */
if (check_all_sections_present(ep, cmd_opts.section_list)) { if (check_all_sections_present(ep, cmd_opts.section_list)) {
ret = -2; ret = -2;
goto free_cmds; goto ret_close_elf;
} }
/* Compute CRCs over sections */ /* Compute CRCs over sections */
crcs = (uint32_t *)malloc(sl_list_length(cmd_opts.section_list) * sizeof(uint32_t)); crcs = (uint32_t *)malloc(sl_list_length(cmd_opts.section_list) * sizeof(uint32_t));
compute_crcs(ep, cmd_opts.section_list, &cmd_opts, crcs); if (compute_crcs(ep, cmd_opts.section_list, &cmd_opts, crcs)) {
goto ret_close_elf;
}
if (reporting_get_verbosity()) { if (reporting_get_verbosity()) {
print_crcs(cmd_opts.section_list, crcs); print_crcs(cmd_opts.section_list, crcs);
@ -427,6 +429,7 @@ int main(int argc, char **argv)
} }
} }
ret_close_elf:
elf_patch_close_and_free(ep); elf_patch_close_and_free(ep);
free_cmds: free_cmds: