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 32b55c5ff9103b8508c1e04bfa5a08c64e7a925f ]
tls_decrypt_sg doesn't take a reference on the pages from clear_skb, so the put_page() in tls_decrypt_done releases them, and we trigger a use-after-free in process_rx_list when we try to read from the partially-read skb.
Fixes: fd31f3996af2 ("tls: rx: decrypt into a fresh skb") Signed-off-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: Jakub Kicinski kuba@kernel.org Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_sw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index ee11932237c0..d651c50746a8 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -62,6 +62,7 @@ struct tls_decrypt_ctx { u8 iv[MAX_IV_SIZE]; u8 aad[TLS_MAX_AAD_SIZE]; u8 tail; + bool free_sgout; struct scatterlist sg[]; };
@@ -186,7 +187,6 @@ static void tls_decrypt_done(crypto_completion_data_t *data, int err) struct aead_request *aead_req = crypto_get_completion_data(data); struct crypto_aead *aead = crypto_aead_reqtfm(aead_req); struct scatterlist *sgout = aead_req->dst; - struct scatterlist *sgin = aead_req->src; struct tls_sw_context_rx *ctx; struct tls_decrypt_ctx *dctx; struct tls_context *tls_ctx; @@ -212,7 +212,7 @@ static void tls_decrypt_done(crypto_completion_data_t *data, int err) }
/* Free the destination pages if skb was not decrypted inplace */ - if (sgout != sgin) { + if (dctx->free_sgout) { /* Skip the first S/G entry as it points to AAD */ for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) { if (!sg) @@ -1653,6 +1653,7 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov, } else if (out_sg) { memcpy(sgout, out_sg, n_sgout * sizeof(*sgout)); } + dctx->free_sgout = !!pages;
/* Prepare and submit AEAD request */ err = tls_do_decryption(sk, sgin, sgout, dctx->iv,