This is a note to let you know that I've just added the patch titled kconfig: fix memory leak from range properties to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kconfig-fix-memory-leak-from-range-properties.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 379bc3ff94894e35c07c93c50c1b75be94ef69e1 Author: Masahiro Yamada <masahiroy@xxxxxxxxxx> Date: Wed Nov 15 13:16:53 2023 +0900 kconfig: fix memory leak from range properties [ Upstream commit ae1eff0349f2e908fc083630e8441ea6dc434dc0 ] 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@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c index 703b9b899ee9c..5adb60b7e12f3 100644 --- a/scripts/kconfig/symbol.c +++ b/scripts/kconfig/symbol.c @@ -119,9 +119,9 @@ 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: @@ -137,17 +137,15 @@ 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)