VYPR
Unrated severityNVD Advisory· Published Mar 1, 2013· Updated Apr 29, 2026

CVE-2011-2491

CVE-2011-2491

Description

The Network Lock Manager (NLM) protocol implementation in the NFS client functionality in the Linux kernel before 3.0 allows local users to cause a denial of service (system hang) via a LOCK_UN flock system call.

Affected products

4

Patches

1
0b760113a3a1

NLM: Don't hang forever on NLM unlock requests

https://github.com/torvalds/linuxTrond MyklebustMay 31, 2011via nvd-ref
4 files changed · +13 2
  • fs/lockd/clntproc.c+7 1 modified
    @@ -708,7 +708,13 @@ static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
     
     	if (task->tk_status < 0) {
     		dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
    -		goto retry_rebind;
    +		switch (task->tk_status) {
    +		case -EACCES:
    +		case -EIO:
    +			goto die;
    +		default:
    +			goto retry_rebind;
    +		}
     	}
     	if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
     		rpc_delay(task, NLMCLNT_GRACE_WAIT);
    
  • include/linux/sunrpc/sched.h+2 1 modified
    @@ -84,7 +84,8 @@ struct rpc_task {
     #endif
     	unsigned char		tk_priority : 2,/* Task priority */
     				tk_garb_retry : 2,
    -				tk_cred_retry : 2;
    +				tk_cred_retry : 2,
    +				tk_rebind_retry : 2;
     };
     #define tk_xprt			tk_client->cl_xprt
     
    
  • net/sunrpc/clnt.c+3 0 modified
    @@ -1175,6 +1175,9 @@ call_bind_status(struct rpc_task *task)
     			status = -EOPNOTSUPP;
     			break;
     		}
    +		if (task->tk_rebind_retry == 0)
    +			break;
    +		task->tk_rebind_retry--;
     		rpc_delay(task, 3*HZ);
     		goto retry_timeout;
     	case -ETIMEDOUT:
    
  • net/sunrpc/sched.c+1 0 modified
    @@ -792,6 +792,7 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta
     	/* Initialize retry counters */
     	task->tk_garb_retry = 2;
     	task->tk_cred_retry = 2;
    +	task->tk_rebind_retry = 2;
     
     	task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW;
     	task->tk_owner = current->tgid;
    

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

5

News mentions

0

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