From: Rick Edgecombe rick.p.edgecombe@intel.com
[ 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@intel.com Signed-off-by: Michael Kelley mhklinux@outlook.com Reviewed-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Link: https://lore.kernel.org/r/20240311161558.1310-4-mhklinux@outlook.com Signed-off-by: Wei Liu wei.liu@kernel.org Message-ID: 20240311161558.1310-4-mhklinux@outlook.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/hyperv/netvsc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
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++) {