From 191644e3d7a6d1b532074225cfd599ec1ed991e6 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 17 Sep 2025 08:28:13 +0800 Subject: [PATCH] tls: make sure to abort the stream if headers are bogus ANBZ: #25821 commit 4cefe5be73886f383639fe0850bb72d5b568a7b9 stable. commit 0aeb54ac4cd5cf8f60131b4d9ec0b6dc9c27b20d upstream. Normally we wait for the socket to buffer up the whole record before we service it. If the socket has a tiny buffer, however, we read out the data sooner, to prevent connection stalls. Make sure that we abort the connection when we find out late that the record is actually invalid. Retrying the parsing is fine in itself but since we copy some more data each time before we parse we can overflow the allocated skb space. Constructing a scenario in which we're under pressure without enough data in the socket to parse the length upfront is quite hard. syzbot figured out a way to do this by serving us the header in small OOB sends, and then filling in the recvbuf with a large normal send. Make sure that tls_rx_msg_size() aborts strp, if we reach an invalid record there's really no way to recover. Reported-by: Lee Jones Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser") Reviewed-by: Sabrina Dubroca Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20250917002814.1743558-1-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Fixes: CVE-2025-39946 Signed-off-by: Xiao Long Signed-off-by: Shiloong --- net/tls/tls.h | 1 + net/tls/tls_strp.c | 14 +++++++++----- net/tls/tls_sw.c | 3 +-- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/net/tls/tls.h b/net/tls/tls.h index 02038d0381b7..d8dbd164e063 100644 --- a/net/tls/tls.h +++ b/net/tls/tls.h @@ -141,6 +141,7 @@ void update_sk_prot(struct sock *sk, struct tls_context *ctx); int wait_on_pending_writer(struct sock *sk, long *timeo); void tls_err_abort(struct sock *sk, int err); +void tls_strp_abort_strp(struct tls_strparser *strp, int err); int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx); void tls_update_rx_zc_capable(struct tls_context *tls_ctx); diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index bea60b0160d1..9b20d5928b73 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -12,7 +12,7 @@ static struct workqueue_struct *tls_strp_wq; -static void tls_strp_abort_strp(struct tls_strparser *strp, int err) +void tls_strp_abort_strp(struct tls_strparser *strp, int err) { if (strp->stopped) return; @@ -210,11 +210,17 @@ static int tls_strp_copyin_frag(struct tls_strparser *strp, struct sk_buff *skb, struct sk_buff *in_skb, unsigned int offset, size_t in_len) { + unsigned int nfrag = skb->len / PAGE_SIZE; size_t len, chunk; skb_frag_t *frag; int sz; - frag = &skb_shinfo(skb)->frags[skb->len / PAGE_SIZE]; + if (unlikely(nfrag >= skb_shinfo(skb)->nr_frags)) { + DEBUG_NET_WARN_ON_ONCE(1); + return -EMSGSIZE; + } + + frag = &skb_shinfo(skb)->frags[nfrag]; len = in_len; /* First make sure we got the header */ @@ -514,10 +520,8 @@ static int tls_strp_read_sock(struct tls_strparser *strp) tls_strp_load_anchor_with_queue(strp, inq); if (!strp->stm.full_len) { sz = tls_rx_msg_size(strp, strp->anchor); - if (sz < 0) { - tls_strp_abort_strp(strp, sz); + if (sz < 0) return sz; - } strp->stm.full_len = sz; diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 4905a81c4ac1..295933aafdbd 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -2435,8 +2435,7 @@ int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb) return data_len + TLS_HEADER_SIZE; read_failure: - tls_err_abort(strp->sk, ret); - + tls_strp_abort_strp(strp, ret); return ret; } -- Gitee