From 32b55c5ff9103b8508c1e04bfa5a08c64e7a925f Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Tue, 6 Feb 2024 17:18:22 -0800 Subject: net: tls: fix use-after-free with partial reads and async decrypt 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 Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- net/tls/tls_sw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 63bef5666e36..a6eff21ade23 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -63,6 +63,7 @@ struct tls_decrypt_ctx { u8 iv[TLS_MAX_IV_SIZE]; u8 aad[TLS_MAX_AAD_SIZE]; u8 tail; + bool free_sgout; struct scatterlist sg[]; }; @@ -187,7 +188,6 @@ static void tls_decrypt_done(void *data, int err) struct aead_request *aead_req = 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; @@ -224,7 +224,7 @@ static void tls_decrypt_done(void *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) @@ -1583,6 +1583,7 @@ 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, -- cgit