[ Upstream commit b281218ad4311a0342a40cb02fb17a363df08b48 ]
There is an out-of-bounds access to "config[len - 1]" array when the variable "len" is zero.
See commit dada6a43b040 ("kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()") for details.
Signed-off-by: Young Xiao YangX92@hotmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/kgdbts.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index de20bdaa148d..8b01257783dd 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -1135,7 +1135,7 @@ static void kgdbts_put_char(u8 chr) static int param_set_kgdbts_var(const char *kmessage, const struct kernel_param *kp) { - int len = strlen(kmessage); + size_t len = strlen(kmessage);
if (len >= MAX_CONFIG_LEN) { printk(KERN_ERR "kgdbts: config string too long\n"); @@ -1155,7 +1155,7 @@ static int param_set_kgdbts_var(const char *kmessage,
strcpy(config, kmessage); /* Chop out \n char as a result of echo */ - if (config[len - 1] == '\n') + if (len && config[len - 1] == '\n') config[len - 1] = '\0';
/* Go and configure with the new params. */