This is a note to let you know that I've just added the patch titled
net/tls: Remove the context from the list in tls_device_down
to the 5.15-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:
net-tls-remove-the-context-from-the-list-in-tls_devi.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e1bf6422281150d1b6fb11cbaeb4d17c644404c8
Author: Maxim Mikityanskiy <maximmi@xxxxxxxxxx>
Date: Thu Jul 21 12:11:27 2022 +0300
net/tls: Remove the context from the list in tls_device_down
[ Upstream commit f6336724a4d4220c89a4ec38bca84b03b178b1a3 ]
tls_device_down takes a reference on all contexts it's going to move to
the degraded state (software fallback). If sk_destruct runs afterwards,
it can reduce the reference counter back to 1 and return early without
destroying the context. Then tls_device_down will release the reference
it took and call tls_device_free_ctx. However, the context will still
stay in tls_device_down_list forever. The list will contain an item,
memory for which is released, making a memory corruption possible.
Fix the above bug by properly removing the context from all lists before
any call to tls_device_free_ctx.
Fixes: 3740651bf7e2 ("tls: Fix context leak on tls_device_down")
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 4e33150cfb9e..cf75969375cf 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -1351,8 +1351,13 @@ static int tls_device_down(struct net_device *netdev)
* by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
* Now release the ref taken above.
*/
- if (refcount_dec_and_test(&ctx->refcount))
+ if (refcount_dec_and_test(&ctx->refcount)) {
+ /* sk_destruct ran after tls_device_down took a ref, and
+ * it returned early. Complete the destruction here.
+ */
+ list_del(&ctx->list);
tls_device_free_ctx(ctx);
+ }
}
up_write(&device_offload_lock);
