Re: unsafe req->rq_xprt using inside bc_svc_process() ?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



I've found that Trond fixed it recently in commit 875f0706acc
"SUNRPC: The TCP back channel mustn't disappear while requests are outstanding"

On 11/29/19 5:10 PM, Vasily Averin wrote:
OpenVz team got complain on crash in bc_svc_process().
Crashed node had 15 running containers with active nfsv4.1 mounts,
single nfsv4.1-svc thread was processed its back-channel requests.
In our case nfs41_callback_svc() took rpc_rqst *req from serv->sv_cb_list
started its processing but found that req->rq_xprt points to already freed
struct rpc_xprt aka part of struct sock_xprt transport.

Back-channel request was submitted via xprt_complete_bc_request(),
its processing uses req->rq_xprt reference in many times,
however I did not found who keeps this reference.
It seems sock_xprt or even whole its net namespace can be freed before bc_svc_process() will start processing of submitted back-channel request, and req->rq_xprt using is unsafe in bc_svc_process()

Am I missed something probably?



[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux