Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
objtool/klp: Avoid NULL pointer dereference when printing code symbol name
Fix a hypothetical NULL pointer defereference of the 'code_sym'
variable. In theory this should never happen.
Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/64116517bc93851a98fe366ea0a4d807f4c70aab.1770759954.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
+9
-6
+9
-6
tools/objtool/klp-diff.c
+9
-6
tools/objtool/klp-diff.c
···
1352
1352
{
1353
1353
bool static_branch = !strcmp(sym->sec->name, "__jump_table");
1354
1354
bool static_call = !strcmp(sym->sec->name, ".static_call_sites");
1355
-
struct symbol *code_sym = NULL;
1355
+
const char *code_sym = NULL;
1356
1356
unsigned long code_offset = 0;
1357
1357
struct reloc *reloc;
1358
1358
int ret = 0;
···
1372
1372
1373
1373
/* Save code location which can be printed below */
1374
1374
if (reloc->sym->type == STT_FUNC && !code_sym) {
1375
-
code_sym = reloc->sym;
1375
+
code_sym = reloc->sym->name;
1376
1376
code_offset = reloc_addend(reloc);
1377
1377
}
1378
1378
···
1395
1395
if (!strcmp(sym_modname, "vmlinux"))
1396
1396
continue;
1397
1397
1398
+
if (!code_sym)
1399
+
code_sym = "<unknown>";
1400
+
1398
1401
if (static_branch) {
1399
1402
if (strstarts(reloc->sym->name, "__tracepoint_")) {
1400
1403
WARN("%s: disabling unsupported tracepoint %s",
1401
-
code_sym->name, reloc->sym->name + 13);
1404
+
code_sym, reloc->sym->name + 13);
1402
1405
ret = 1;
1403
1406
continue;
1404
1407
}
1405
1408
1406
1409
if (strstr(reloc->sym->name, "__UNIQUE_ID_ddebug_")) {
1407
1410
WARN("%s: disabling unsupported pr_debug()",
1408
-
code_sym->name);
1411
+
code_sym);
1409
1412
ret = 1;
1410
1413
continue;
1411
1414
}
1412
1415
1413
1416
ERROR("%s+0x%lx: unsupported static branch key %s. Use static_key_enabled() instead",
1414
-
code_sym->name, code_offset, reloc->sym->name);
1417
+
code_sym, code_offset, reloc->sym->name);
1415
1418
return -1;
1416
1419
}
1417
1420
···
1425
1422
}
1426
1423
1427
1424
ERROR("%s()+0x%lx: unsupported static call key %s. Use KLP_STATIC_CALL() instead",
1428
-
code_sym->name, code_offset, reloc->sym->name);
1425
+
code_sym, code_offset, reloc->sym->name);
1429
1426
return -1;
1430
1427
}
1431
1428