[PATCH net v2 1/2] net/tls: Fix flipped sign in tls_err_abort() calls
From: Daniel Jordan <daniel.m.jordan@oracle.com>
Date: 2021-10-27 22:00:02
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>
---
include/net/tls.h | 9 ++-------
net/tls/tls_sw.c | 17 +++++++++++++----
2 files changed, 15 insertions(+), 11 deletions(-)
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;
base-commit: 6f7c88691191e6c52ef2543d6f1da8d360b27a24 -- 2.33.0