This is a note to let you know that I've just added the patch titled
hv_netvsc: Don't free decrypted memory
to the 6.8-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:
hv_netvsc-don-t-free-decrypted-memory.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e6a982927c89357a0c6442d9aa4337f88a2fa46c
Author: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Date: Mon Mar 11 09:15:56 2024 -0700
hv_netvsc: Don't free decrypted memory
[ Upstream commit bbf9ac34677b57506a13682b31a2a718934c0e31 ]
In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
The netvsc driver could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the gpadl
to decide whether to free the memory.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240311161558.1310-4-mhklinux@xxxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Message-ID: <20240311161558.1310-4-mhklinux@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index a6fcbda64ecc6..2b6ec979a62f2 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -154,8 +154,11 @@ static void free_netvsc_device(struct rcu_head *head)
int i;
kfree(nvdev->extension);
- vfree(nvdev->recv_buf);
- vfree(nvdev->send_buf);
+
+ if (!nvdev->recv_buf_gpadl_handle.decrypted)
+ vfree(nvdev->recv_buf);
+ if (!nvdev->send_buf_gpadl_handle.decrypted)
+ vfree(nvdev->send_buf);
bitmap_free(nvdev->send_section_map);
for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
