Resending since this problem still appears to be in
both the -mm and mainline kernels..
steved.
-------- Original Message --------
Subject: [PATCH] NFS/RPC/GSS - oops in gss_pipe_release()
Date: Fri, 16 Sep 2005 13:40:15 -0400
From: Steve Dickson <[email protected]>
To: [email protected]
During some recent debugging I found that an oops can
occur in gss_pipe_release() because the client handle
that is being passed in has already been freed.
The scenario is as follows:
1) root# mount -o sec=krb5 server:/export /mnt/export
2) user$ ls /mnt/export (which hangs because user does not
have the correct credentials)
3) root# reboot
The oops occurs when the /mnt/export filesystem
is unmounted. The reason being is gss_pipe_release()
was already called when the ls process was killed.
The stack dump of the ls process was:
[<e09dda84>] gss_pipe_release+0x74/0xd8 [auth_rpcgss]
[<e0a045c0>] rpc_pipe_release+0xa5/0xb9 [sunrpc]
[<c015a9d6>] __fput+0x55/0x100
[<c0159626>] filp_close+0x59/0x5f
[<c012363f>] put_files_struct+0x57/0xc0
[<c0124255>] do_exit+0x227/0x3de
[<c01244fa>] sys_exit_group+0x0/0xd
[<c02d120b>] syscall_call+0x7/0xb
So when the rpc_shutdown_client code is called
via the umount:
[<e09dda84>] gss_pipe_release+0x74/0xd8 [auth_rpcgss]
[<e0a0447c>] rpc_close_pipes+0x80/0x9a [sunrpc]
[<e0a04bb0>] rpc_depopulate+0xfb/0x142 [sunrpc]
[<c01651bc>] cached_lookup+0xf/0x56
[<c0166410>] __lookup_hash+0x46/0x89
[<e0a05005>] rpc_rmdir+0x5a/0x89 [sunrpc]
[<e09fcede>] rpcauth_free_credcache+0x87/0xd0 [sunrpc]
[<e09f8431>] rpc_destroy_client+0x70/0xa4 [sunrpc]
[<e09f8421>] rpc_destroy_client+0x60/0xa4 [sunrpc]
[<e09f83ba>] rpc_shutdown_client+0xd1/0xd8 [sunrpc]
[<c011e586>] default_wake_function+0x0/0xc
[<e0aefe75>] nfs_kill_super+0x38/0x63 [nfs]
the client handle (which is in the rpc_inode) passed
to gss_pipe_release() has already been freeded.
It appears from other places in the code (namely
rpc_close_pipes()) that the only way to invalidate
an rpc_inode is to set the ops pointer to NULL which
is what the attached patch does.
Is there a better way to invalid an rpc_inode?
steved.
This patch stops the release_pipe() funtion from being called
twice by invalidating the ops pointer in the rpc_inode
when rpc_pipe_release() is called.
Signed-off-by: Steve Dickson <[email protected]>
------------------------------------------------------
--- linux-2.6.13/net/sunrpc/rpc_pipe.c.orig 2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13/net/sunrpc/rpc_pipe.c 2005-09-16 11:18:53.598157000 -0400
@@ -177,6 +177,8 @@ rpc_pipe_release(struct inode *inode, st
__rpc_purge_upcall(inode, -EPIPE);
if (rpci->ops->release_pipe)
rpci->ops->release_pipe(inode);
+ if (!rpci->nreaders && !rpci->nwriters)
+ rpci->ops = NULL;
out:
up(&inode->i_sem);
return 0;
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
