6.1-stable review patch. If anyone has any objections, please let me know.
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From: Sabrina Dubroca sd@queasysnail.net
[ Upstream commit 6caaf104423d809b49a67ee6500191d063b40dc6 ]
If we peek from 2 records with a currently empty rx_list, and the first record is decrypted synchronously but the second record is decrypted async, the following happens: 1. decrypt record 1 (sync) 2. copy from record 1 to the userspace's msg 3. queue the decrypted record to rx_list for future read(!PEEK) 4. decrypt record 2 (async) 5. queue record 2 to rx_list 6. call process_rx_list to copy data from the 2nd record
We currently pass copied=0 as skip offset to process_rx_list, so we end up copying once again from the first record. We should skip over the data we've already copied.
Seen with selftest tls.12_aes_gcm.recv_peek_large_buf_mult_recs
Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") Signed-off-by: Sabrina Dubroca sd@queasysnail.net Link: https://lore.kernel.org/r/1b132d2b2b99296bfde54e8a67672d90d6d16e71.170913264... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_sw.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index c6ad435a44218..2bd27b77769cb 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -2023,6 +2023,7 @@ int tls_sw_recvmsg(struct sock *sk, struct strp_msg *rxm; struct tls_msg *tlm; ssize_t copied = 0; + ssize_t peeked = 0; bool async = false; int target, err; bool is_kvec = iov_iter_is_kvec(&msg->msg_iter); @@ -2170,8 +2171,10 @@ int tls_sw_recvmsg(struct sock *sk, if (err < 0) goto put_on_rx_list_err;
- if (is_peek) + if (is_peek) { + peeked += chunk; goto put_on_rx_list; + }
if (partially_consumed) { rxm->offset += chunk; @@ -2210,8 +2213,8 @@ int tls_sw_recvmsg(struct sock *sk,
/* Drain records from the rx_list & copy if required */ if (is_peek || is_kvec) - err = process_rx_list(ctx, msg, &control, copied, - decrypted, is_peek, NULL); + err = process_rx_list(ctx, msg, &control, copied + peeked, + decrypted - peeked, is_peek, NULL); else err = process_rx_list(ctx, msg, &control, 0, async_copy_bytes, is_peek, NULL);