5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Masahiro Yamada masahiroy@kernel.org
[ 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: Masahiro Yamada masahiroy@kernel.org Stable-dep-of: a409fc1463d6 ("kconfig: fix memory leak in sym_warn_unmet_dep()") Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/kconfig/confdata.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c index 033f2882436d3..80160aee01ff6 100644 --- a/scripts/kconfig/confdata.c +++ b/scripts/kconfig/confdata.c @@ -434,6 +434,8 @@ 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_), ' ');