6.12-stable review patch. If anyone has any objections, please let me know.
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From: Jakub Kicinski kuba@kernel.org
[ Upstream commit 0aeb54ac4cd5cf8f60131b4d9ec0b6dc9c27b20d ]
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 lee@kernel.org Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser") Reviewed-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: Jakub Kicinski kuba@kernel.org Link: https://patch.msgid.link/20250917002814.1743558-1-kuba@kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 e1eaf12b37426..fca0c0e170047 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 init_prot_info(struct tls_prot_info *prot, const struct tls_crypto_info *crypto_info, diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index d71643b494a1a..98e12f0ff57e5 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -13,7 +13,7 @@
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; @@ -211,11 +211,17 @@ 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 */ @@ -520,10 +526,8 @@ 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 ee92ce3255f93..f46550b96061e 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -2440,8 +2440,7 @@ 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; }