Function may race with vsock_core_unregister(): transport_g2h may become
NULL after the NULL check. Protect from a potential null-ptr-deref.
KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
RIP: 0010:vsock_find_cid+0x47/0x90
Call Trace:
__vsock_bind+0x4b2/0x720
vsock_bind+0x90/0xe0
__sys_bind+0x14d/0x1e0
__x64_sys_bind+0x6e/0xc0
do_syscall_64+0x92/0x1c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
---
net/vmw_vsock/af_vsock.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 047d1bc773fab9c315a6ccd383a451fa11fb703e..337540efc237c8bc482a6730948fc773c00854f1 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -533,8 +533,10 @@ EXPORT_SYMBOL_GPL(vsock_assign_transport);
bool vsock_find_cid(unsigned int cid)
{
- if (transport_g2h && cid == transport_g2h->get_local_cid())
- return true;
+ scoped_guard(mutex, &vsock_register_mutex) {
+ if (transport_g2h && cid == transport_g2h->get_local_cid())
+ return true;
+ }
if (transport_h2g && cid == VMADDR_CID_HOST)
return true;
--
2.49.0