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[SRU,M,7/8] net: tls: fix use-after-free with partial reads and async decrypt

Message ID 20240325103300.494141-8-juerg.haefliger@canonical.com
State New
Headers show
Series Fix for CVE-2024-2658{2,3,4,5} | expand

Commit Message

Juerg Haefliger March 25, 2024, 10:32 a.m. UTC 
From: Sabrina Dubroca <sd@queasysnail.net>

CVE-2024-26582

[ 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>
(cherry picked from commit d684763534b969cca1022e2a28645c7cc91f7fa5 linux-6.6.y)
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
---
 net/tls/tls_sw.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index ad7ed6c203a9..1a814907adfe 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -63,6 +63,7 @@  struct tls_decrypt_ctx {
 	u8 iv[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)
@@ -1580,6 +1580,7 @@  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,