Commit 005da237 authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Wentao Guan
Browse files

kconfig: require a space after '#' for valid input 

stable inclusion
from stable-v6.6.76
commit 26341c1bb7666c0e09a0f92c91567855e1e7fbe3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBW08Q

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=26341c1bb7666c0e09a0f92c91567855e1e7fbe3



--------------------------------

[ Upstream commit 4d137ab0107ead0f2590fc0314e627431e3b9e3f ]

Currently, when an input line starts with '#', (line + 2) is passed to
memcmp() without checking line[1].

It means that line[1] can be any arbitrary character. For example,
"#KCONFIG_FOO is not set" is accepted as valid input, functioning the
same as "# CONFIG_FOO is not set".

More importantly, this can potentially lead to a buffer overrun if
line[1] == '\0'. It occurs if the input only contains '#', as
(line + 2) points to an uninitialized buffer.

Check line[1], and skip the line if it is not a space.

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: a409fc1463d6 ("kconfig: fix memory leak in sym_warn_unmet_dep()")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
(cherry picked from commit 26341c1bb7666c0e09a0f92c91567855e1e7fbe3)
Signed-off-by: default avatarWentao Guan <guanwentao@uniontech.com>
parent 8fa69088

scripts/kconfig/confdata.c

+2 −0
Original line number Diff line number Diff line
@@ -432,6 +432,8 @@ int conf_read_simple(const char *name, int def) 
		conf_lineno++;

		sym = NULL;

		if (line[0] == '#') {

			if (line[1] != ' ')

				continue;

			if (memcmp(line + 2, CONFIG_, strlen(CONFIG_)))

				continue;

			p = strchr(line + 2 + strlen(CONFIG_), ' ');