This is a note to let you know that I've just added the patch titled
tls: fix use-after-free on failed backlog decryption
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tls-fix-use-after-free-on-failed-backlog-decryption.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 13114dc5543069f7b97991e3b79937b6da05f5b0 Mon Sep 17 00:00:00 2001
From: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Date: Wed, 28 Feb 2024 23:44:00 +0100
Subject: tls: fix use-after-free on failed backlog decryption
From: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
commit 13114dc5543069f7b97991e3b79937b6da05f5b0 upstream.
When the decrypt request goes to the backlog and crypto_aead_decrypt
returns -EBUSY, tls_do_decryption will wait until all async
decryptions have completed. If one of them fails, tls_do_decryption
will return -EBADMSG and tls_decrypt_sg jumps to the error path,
releasing all the pages. But the pages have been passed to the async
callback, and have already been released by tls_decrypt_done.
The only true async case is when crypto_aead_decrypt returns
-EINPROGRESS. With -EBUSY, we already waited so we can tell
tls_sw_recvmsg that the data is available for immediate copy, but we
need to notify tls_decrypt_sg (via the new ->async_done flag) that the
memory has already been released.
Fixes: 859054147318 ("net: tls: handle backlogging of crypto requests")
Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/4755dd8d9bebdefaa19ce1439b833d6199d4364c.1709132643.git.sd@xxxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/tls/tls_sw.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -51,6 +51,7 @@ struct tls_decrypt_arg {
struct_group(inargs,
bool zc;
bool async;
+ bool async_done;
u8 tail;
);
@@ -279,18 +280,19 @@ static int tls_do_decryption(struct sock
}
ret = crypto_aead_decrypt(aead_req);
+ if (ret == -EINPROGRESS)
+ return 0;
+
if (ret == -EBUSY) {
ret = tls_decrypt_async_wait(ctx);
+ darg->async_done = true;
+ /* all completions have run, we're not doing async anymore */
+ darg->async = false;
+ return ret;
ret = ret ?: -EINPROGRESS;
}
- if (ret == -EINPROGRESS) {
- if (darg->async)
- return 0;
- ret = crypto_wait_req(ret, &ctx->async_wait);
- } else if (darg->async) {
- atomic_dec(&ctx->decrypt_pending);
- }
+ atomic_dec(&ctx->decrypt_pending);
darg->async = false;
return ret;
@@ -1681,8 +1683,11 @@ static int tls_decrypt_sg(struct sock *s
/* Prepare and submit AEAD request */
err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
data_len + prot->tail_size, aead_req, darg);
- if (err)
+ if (err) {
+ if (darg->async_done)
+ goto exit_free_skb;
goto exit_free_pages;
+ }
darg->skb = clear_skb ?: tls_strp_msg(ctx);
clear_skb = NULL;
@@ -1694,6 +1699,9 @@ static int tls_decrypt_sg(struct sock *s
return err;
}
+ if (unlikely(darg->async_done))
+ return 0;
+
if (prot->tail_size)
darg->tail = dctx->tail;
Patches currently in stable-queue which might be from sd@xxxxxxxxxxxxxxx are
queue-6.1/tls-fix-use-after-free-on-failed-backlog-decryption.patch
queue-6.1/net-tls-handle-backlogging-of-crypto-requests.patch
queue-6.1/tls-fix-race-between-tx-work-scheduling-and-socket-close.patch
