The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From da353fac65fede6b8b4cfe207f0d9408e3121105 Mon Sep 17 00:00:00 2001

From: Daniel Jordan daniel.m.jordan@oracle.com Date: Wed, 27 Oct 2021 17:59:20 -0400 Subject: [PATCH] net/tls: Fix flipped sign in tls_err_abort() calls

sk->sk_err appears to expect a positive value, a convention that ktls doesn't always follow and that leads to memory corruption in other code. For instance,

[kworker] tls_encrypt_done(..., err=<negative error from crypto request>) tls_err_abort(.., err) sk->sk_err = err;

[task] splice_from_pipe_feed ... tls_sw_do_sendpage if (sk->sk_err) { ret = -sk->sk_err; // ret is positive

splice_from_pipe_feed (continued) ret = actor(...) // ret is still positive and interpreted as bytes // written, resulting in underflow of buf->len and // sd->len, leading to huge buf->offset and bogus // addresses computed in later calls to actor()

Fix all tls_err_abort() callers to pass a negative error code consistently and centralize the error-prone sign flip there, throwing in a warning to catch future misuse and uninlining the function so it really does only warn once.

Cc: stable@vger.kernel.org Fixes: c46234ebb4d1e ("tls: RX path for ktls") Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com Signed-off-by: Daniel Jordan daniel.m.jordan@oracle.com Signed-off-by: David S. Miller davem@davemloft.net

diff --git a/include/net/tls.h b/include/net/tls.h index 01d2e3744393..1fffb206f09f 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -358,6 +358,7 @@ int tls_sk_query(struct sock *sk, int optname, char __user *optval, int __user *optlen); int tls_sk_attach(struct sock *sk, int optname, char __user *optval, unsigned int optlen); +void tls_err_abort(struct sock *sk, int err);

int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx); void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx); @@ -466,12 +467,6 @@ static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk) #endif }

-static inline void tls_err_abort(struct sock *sk, int err) -{ - sk->sk_err = err; - sk_error_report(sk); -} - static inline bool tls_bigint_increment(unsigned char *seq, int len) { int i; @@ -512,7 +507,7 @@ static inline void tls_advance_record_sn(struct sock *sk, struct cipher_context *ctx) { if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size)) - tls_err_abort(sk, EBADMSG); + tls_err_abort(sk, -EBADMSG);

if (prot->version != TLS_1_3_VERSION && prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index d5d09bd817b7..1644f8baea19 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -35,6 +35,7 @@ * SOFTWARE. */

+#include <linux/bug.h> #include <linux/sched/signal.h> #include <linux/module.h> #include <linux/splice.h> @@ -43,6 +44,14 @@ #include <net/strparser.h> #include <net/tls.h>

+noinline void tls_err_abort(struct sock *sk, int err) +{ + WARN_ON_ONCE(err >= 0); + /* sk->sk_err should contain a positive error code. */ + sk->sk_err = -err; + sk_error_report(sk); +} + static int __skb_nsg(struct sk_buff *skb, int offset, int len, unsigned int recursion_level) { @@ -419,7 +428,7 @@ int tls_tx_records(struct sock *sk, int flags)

tx_err: if (rc < 0 && rc != -EAGAIN) - tls_err_abort(sk, EBADMSG); + tls_err_abort(sk, -EBADMSG);

return rc; } @@ -763,7 +772,7 @@ static int tls_push_record(struct sock *sk, int flags, msg_pl->sg.size + prot->tail_size, i); if (rc < 0) { if (rc != -EINPROGRESS) { - tls_err_abort(sk, EBADMSG); + tls_err_abort(sk, -EBADMSG); if (split) { tls_ctx->pending_open_record_frags = true; tls_merge_open_record(sk, rec, tmp, orig_end); @@ -1827,7 +1836,7 @@ int tls_sw_recvmsg(struct sock *sk, err = decrypt_skb_update(sk, skb, &msg->msg_iter, &chunk, &zc, async_capable); if (err < 0 && err != -EINPROGRESS) { - tls_err_abort(sk, EBADMSG); + tls_err_abort(sk, -EBADMSG); goto recv_end; }

@@ -2007,7 +2016,7 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos, }

if (err < 0) { - tls_err_abort(sk, EBADMSG); + tls_err_abort(sk, -EBADMSG); goto splice_read_end; } ctx->decrypted = 1;