syzbot is reporting uninit-value at aes_encrypt(), for block cipher assumes
that bytes to encrypt/decrypt is multiple of block size for that cipher but
tls_alloc_encrypted_msg() is not initializing padding bytes when
required_size is not multiple of block cipher's block size.
In order to make sure that padding bytes are automatically initialized,
enable __GFP_ZERO flag when setsockopt(SOL_TCP, TCP_ULP, "tls") is called.
Reported-by: syzbot <[email protected]>
Closes: https://syzkaller.appspot.com/bug?extid=828dfc12440b4f6f305d
Signed-off-by: Tetsuo Handa <[email protected]>
---
According to C reproducer, this problem happens when bpf_exec_tx_verdict() is
called with lower 4 bits of required_size being 0001 and does not happen when
being 0100. Thus, I assumed that this problem is caused by lack of initializing
padding bytes.
But I couldn't figure out why KMSAN reports this problem when bpf_exec_tx_verdict()
is called with lower 4 bits of required_size being 0001 for the second time and
does not report this problem when bpf_exec_tx_verdict() is called with lower
4 bits of required_size being 0001 for the first time. More deeper problem exists?
KMSAN reporting this problem when accessing u64 relevant?
net/tls/tls_main.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index f2e7302a4d96..cd5366966864 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -1025,6 +1025,7 @@ static int tls_init(struct sock *sk)
struct tls_context *ctx;
int rc = 0;
+ sk->sk_allocation |= __GFP_ZERO;
tls_build_proto(sk);
#ifdef CONFIG_TLS_TOE
--
2.34.1