5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jakub Kicinski kuba@kernel.org
[ Upstream commit 9bdf75ccffa690237cd0b472cd598cf6d22873dc ]
We plumb pointer to chunk all the way to the decryption method. It's set to the length of the text when decrypt_skb_update() returns.
I think the code is written this way because original TLS implementation passed &chunk to zerocopy_from_iter() and this was carried forward as the code gotten more complex, without any refactoring.
The fix for peek() introduced a new variable - to_decrypt which for all practical purposes is what chunk is going to get set to. Spare ourselves the pointer passing, use to_decrypt.
Use this opportunity to clean things up a little further.
Note that chunk / to_decrypt was mostly needed for the async path, since the sync path would access rxm->full_len (decryption transforms full_len from record size to text size). Use the right source of truth more explicitly.
We have three cases: - async - it's TLS 1.2 only, so chunk == to_decrypt, but we need the min() because to_decrypt is a whole record and we don't want to underflow len. Note that we can't handle partial record by falling back to sync as it would introduce reordering against records in flight. - zc - again, TLS 1.2 only for now, so chunk == to_decrypt, we don't do zc if len < to_decrypt, no need to check again. - normal - it already handles chunk > len, we can factor out the assignment to rxm->full_len and share it with zc.
Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: f7fa16d49837 ("tls: decrement decrypt_pending if no async completion will be called") Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_sw.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index cf09f147f5a09..fc1fa98d21937 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1415,7 +1415,7 @@ static int tls_setup_from_iter(struct iov_iter *from, static int decrypt_internal(struct sock *sk, struct sk_buff *skb, struct iov_iter *out_iov, struct scatterlist *out_sg, - int *chunk, bool *zc, bool async) + bool *zc, bool async) { struct tls_context *tls_ctx = tls_get_ctx(sk); struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx); @@ -1522,7 +1522,6 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, (n_sgout - 1)); if (err < 0) goto fallback_to_reg_recv; - *chunk = data_len; } else if (out_sg) { memcpy(sgout, out_sg, n_sgout * sizeof(*sgout)); } else { @@ -1532,7 +1531,6 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, fallback_to_reg_recv: sgout = sgin; pages = 0; - *chunk = data_len; *zc = false; }
@@ -1551,8 +1549,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, }
static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb, - struct iov_iter *dest, int *chunk, bool *zc, - bool async) + struct iov_iter *dest, bool *zc, bool async) { struct tls_context *tls_ctx = tls_get_ctx(sk); struct tls_prot_info *prot = &tls_ctx->prot_info; @@ -1576,7 +1573,7 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb, } }
- err = decrypt_internal(sk, skb, dest, NULL, chunk, zc, async); + err = decrypt_internal(sk, skb, dest, NULL, zc, async); if (err < 0) { if (err == -EINPROGRESS) tls_advance_record_sn(sk, prot, &tls_ctx->rx); @@ -1603,9 +1600,8 @@ int decrypt_skb(struct sock *sk, struct sk_buff *skb, struct scatterlist *sgout) { bool zc = true; - int chunk;
- return decrypt_internal(sk, skb, NULL, sgout, &chunk, &zc, false); + return decrypt_internal(sk, skb, NULL, sgout, &zc, false); }
static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb, @@ -1795,9 +1791,8 @@ int tls_sw_recvmsg(struct sock *sk, num_async = 0; while (len && (decrypted + copied < target || ctx->recv_pkt)) { bool retain_skb = false; + int to_decrypt, chunk; bool zc = false; - int to_decrypt; - int chunk = 0; bool async_capable; bool async = false;
@@ -1834,7 +1829,7 @@ int tls_sw_recvmsg(struct sock *sk, async_capable = false;
err = decrypt_skb_update(sk, skb, &msg->msg_iter, - &chunk, &zc, async_capable); + &zc, async_capable); if (err < 0 && err != -EINPROGRESS) { tls_err_abort(sk, -EBADMSG); goto recv_end; @@ -1872,8 +1867,13 @@ int tls_sw_recvmsg(struct sock *sk, } }
- if (async) + if (async) { + /* TLS 1.2-only, to_decrypt must be text length */ + chunk = min_t(int, to_decrypt, len); goto pick_next_record; + } + /* TLS 1.3 may have updated the length by more than overhead */ + chunk = rxm->full_len;
if (!zc) { if (bpf_strp_enabled) { @@ -1889,11 +1889,9 @@ int tls_sw_recvmsg(struct sock *sk, } }
- if (rxm->full_len > len) { + if (chunk > len) { retain_skb = true; chunk = len; - } else { - chunk = rxm->full_len; }
err = skb_copy_datagram_msg(skb, rxm->offset, @@ -1908,9 +1906,6 @@ int tls_sw_recvmsg(struct sock *sk, }
pick_next_record: - if (chunk > len) - chunk = len; - decrypted += chunk; len -= chunk;
@@ -2011,7 +2006,7 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos, if (!skb) goto splice_read_end;
- err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc, false); + err = decrypt_skb_update(sk, skb, NULL, &zc, false); if (err < 0) { tls_err_abort(sk, -EBADMSG); goto splice_read_end;