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net: tls: fix use-after-free with partial reads and async decrypt

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[ 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>
This commit is contained in:
Sabrina Dubroca 2024-02-06 17:18:22 -08:00 committed by Greg Kroah-Hartman
parent 7a3ca06d04
commit 20b4ed0348
1 changed files with 3 additions and 2 deletions
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5
net/tls/tls_sw.c
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@ -62,6 +62,7 @@ struct tls_decrypt_ctx {
u8 iv[MAX_IV_SIZE]; u8 iv[MAX_IV_SIZE];
u8 aad[TLS_MAX_AAD_SIZE]; u8 aad[TLS_MAX_AAD_SIZE];
u8 tail; u8 tail;
bool free_sgout;
struct scatterlist sg[]; 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 aead_request *aead_req = crypto_get_completion_data(data);
struct crypto_aead *aead = crypto_aead_reqtfm(aead_req); struct crypto_aead *aead = crypto_aead_reqtfm(aead_req);
struct scatterlist *sgout = aead_req->dst; struct scatterlist *sgout = aead_req->dst;
struct scatterlist *sgin = aead_req->src;
struct tls_sw_context_rx *ctx; struct tls_sw_context_rx *ctx;
struct tls_decrypt_ctx *dctx; struct tls_decrypt_ctx *dctx;
struct tls_context *tls_ctx; 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 */ /* 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 */ /* Skip the first S/G entry as it points to AAD */
for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) { for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
if (!sg) if (!sg)
@ -1653,6 +1653,7 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
} else if (out_sg) { } else if (out_sg) {
memcpy(sgout, out_sg, n_sgout * sizeof(*sgout)); memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
} }
dctx->free_sgout = !!pages;
/* Prepare and submit AEAD request */ /* Prepare and submit AEAD request */
err = tls_do_decryption(sk, sgin, sgout, dctx->iv, err = tls_do_decryption(sk, sgin, sgout, dctx->iv,