[PATCH] afs: Fix poential UAF in afs_make_call

From: Zheng Wang
Date: Thu Dec 29 2022 - 11:41:58 EST


There is a function call : afs_fs_get_capabilities calls afs_make_call, in
afs_make_call, if error occurs in rxrpc_kernel_send_data, it will call
afs_put_call twice, which will free the call. And the access of
call->state will trigger a use-after-free bug.

Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
---
fs/afs/rxrpc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index c62939e5ea1f..4871210c4b81 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -422,8 +422,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
call->rxcall = NULL;
}
if (call->async) {
- if (cancel_work_sync(&call->async_work))
- afs_put_call(call);
+ cancel_work_sync(&call->async_work);
afs_put_call(call);
}

--
2.25.1