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kconfig: fix memory leak from range properties

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Currently, sym_validate_range() duplicates the range string using
xstrdup(), which is overwritten by a subsequent sym_calc_value() call.
It results in a memory leak.

Instead, only the pointer should be copied.

Below is a test case, with a summary from Valgrind.

[Test Kconfig]

  config FOO
          int "foo"
          range 10 20

[Test .config]

  CONFIG_FOO=0

[Before]

  LEAK SUMMARY:
     definitely lost: 3 bytes in 1 blocks
     indirectly lost: 0 bytes in 0 blocks
       possibly lost: 0 bytes in 0 blocks
     still reachable: 17,465 bytes in 21 blocks
          suppressed: 0 bytes in 0 blocks

[After]

  LEAK SUMMARY:
     definitely lost: 0 bytes in 0 blocks
     indirectly lost: 0 bytes in 0 blocks
       possibly lost: 0 bytes in 0 blocks
     still reachable: 17,462 bytes in 20 blocks
          suppressed: 0 bytes in 0 blocks

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2023-11-15 13:16:53 +09:00
parent 76020731d4
commit ae1eff0349
1 changed files with 6 additions and 8 deletions
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14
scripts/kconfig/symbol.c
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@ -122,9 +122,9 @@ static long long sym_get_range_val(struct symbol *sym, int base)
static void sym_validate_range(struct symbol *sym)
{
struct property *prop;
struct symbol *range_sym;
int base;
long long val, val2;
char str[64];
switch (sym->type) {
case S_INT:
@ -140,17 +140,15 @@ static void sym_validate_range(struct symbol *sym)
if (!prop)
return;
val = strtoll(sym->curr.val, NULL, base);
val2 = sym_get_range_val(prop->expr->left.sym, base);
range_sym = prop->expr->left.sym;
val2 = sym_get_range_val(range_sym, base);
if (val >= val2) {
val2 = sym_get_range_val(prop->expr->right.sym, base);
range_sym = prop->expr->right.sym;
val2 = sym_get_range_val(range_sym, base);
if (val <= val2)
return;
}
if (sym->type == S_INT)
sprintf(str, "%lld", val2);
else
sprintf(str, "0x%llx", val2);
sym->curr.val = xstrdup(str);
sym->curr.val = range_sym->curr.val;
}
static void sym_set_changed(struct symbol *sym)