From: Alexey Kodanev <aleksei.kodanev@xxxxxxxxxxx> [ Upstream commit 7a7b7f575a25aa68ee934ee8107294487efcb3fe ] strnlen() may return 0 (e.g. for "\0\n" string), it's better to check the result of strnlen() before using 'len - 1' expression for the 'buf' array index. Detected using the static analysis tool - Svace. Fixes: dc3b66a0ce70 ("RDMA/rtrs-clt: Add a minimum latency multipath policy") Signed-off-by: Alexey Kodanev <aleksei.kodanev@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20240221113204.147478-1-aleksei.kodanev@xxxxxxxxxxx Acked-by: Jack Wang <jinpu.wang@xxxxxxxxx> Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c index dbf9a778c3bd7..583c38eb04326 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c @@ -131,7 +131,7 @@ static ssize_t mpath_policy_store(struct device *dev, /* distinguish "mi" and "min-latency" with length */ len = strnlen(buf, NAME_MAX); - if (buf[len - 1] == '\n') + if (len && buf[len - 1] == '\n') len--; if (!strncasecmp(buf, "round-robin", 11) || -- 2.43.0