As of eb6dc19d8e72ce3a957af5511d20c0db0a8bd007 "RPCSEC_GSS: Share all credential caches on a per-transport basis" I'm getting an occasional crash on shutdown of nfsd's 4.0 callback client (see appended oops), because rpc_shutdown_client() is called on a client whose cl_auth is a gss_auth with gss_pipe[0]->clnt pointing to freed memory. Is there any known bug here? While I try to understand this.... I'm wondering what guarantees that gss_pipe[0]->clnt is still good at this point, and that leads me to be suspicious of the sharing introduced by this patch--how do we know that a gss_auth can't be shared between two clients that could disappear in either order? The chasing of cl_parent pointers in gss_create() suggests that the auth's pointers back to clients are always supposed to be back to a common ancestor, but does gss_auth_find_or_add_hashed really guarantee that the auth will only be shared between clients that are cloned from a common ancestor? --b. general protection fault: 0000 [#1] PREEMPT SMP Modules linked in: rpcsec_gss_krb5 nfsd auth_rpcgss oid_registry nfs_acl lockd sunrpc CPU: 3 PID: 4071 Comm: kworker/u8:2 Not tainted 3.11.0-rc2-00182-g025145f #1665 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: nfsd4_callbacks nfsd4_do_callback_rpc [nfsd] task: ffff88003e206080 ti: ffff88003c384000 task.ti: ffff88003c384000 RIP: 0010:[<ffffffffa00001f3>] [<ffffffffa00001f3>] rpc_net_ns+0x53/0x70 [sunrpc] RSP: 0000:ffff88003c385ab8 EFLAGS: 00010246 RAX: 6b6b6b6b6b6b6b6b RBX: ffff88003af9a800 RCX: 0000000000000002 RDX: ffffffffa00001a5 RSI: 0000000000000001 RDI: ffffffff81e284e0 RBP: ffff88003c385ad8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000015 R12: ffff88003c990840 R13: ffff88003c990878 R14: ffff88003c385ba8 R15: ffff88003e206080 FS: 0000000000000000(0000) GS:ffff88003fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007fcdf737e000 CR3: 000000003ad2b000 CR4: 00000000000006e0 Stack: ffffffffa00001a5 0000000000000006 0000000000000006 ffff88003af9a800 ffff88003c385b08 ffffffffa00d52a4 ffff88003c385ba8 ffff88003c751bd8 ffff88003c751bc0 ffff88003e113600 ffff88003c385b18 ffffffffa00d530c Call Trace: [<ffffffffa00001a5>] ? rpc_net_ns+0x5/0x70 [sunrpc] [<ffffffffa00d52a4>] __gss_pipe_release+0x54/0x90 [auth_rpcgss] [<ffffffffa00d530c>] gss_pipe_free+0x2c/0x30 [auth_rpcgss] [<ffffffffa00d678b>] gss_destroy+0x9b/0xf0 [auth_rpcgss] [<ffffffffa000de63>] rpcauth_release+0x23/0x30 [sunrpc] [<ffffffffa0001e81>] rpc_release_client+0x51/0xb0 [sunrpc] [<ffffffffa00020d5>] rpc_shutdown_client+0xe5/0x170 [sunrpc] [<ffffffff81098a14>] ? cpuacct_charge+0xa4/0xb0 [<ffffffff81098975>] ? cpuacct_charge+0x5/0xb0 [<ffffffffa019556f>] nfsd4_process_cb_update.isra.17+0x2f/0x210 [nfsd] [<ffffffff819a4ac0>] ? _raw_spin_unlock_irq+0x30/0x60 [<ffffffff819a4acb>] ? _raw_spin_unlock_irq+0x3b/0x60 [<ffffffff810703ab>] ? process_one_work+0x15b/0x510 [<ffffffffa01957dd>] nfsd4_do_callback_rpc+0x8d/0xa0 [nfsd] [<ffffffff8107041e>] process_one_work+0x1ce/0x510 [<ffffffff810703ab>] ? process_one_work+0x15b/0x510 [<ffffffff810712ab>] worker_thread+0x11b/0x370 [<ffffffff81071190>] ? manage_workers.isra.24+0x2b0/0x2b0 [<ffffffff8107854b>] kthread+0xdb/0xe0 [<ffffffff819a4ac0>] ? _raw_spin_unlock_irq+0x30/0x60 [<ffffffff81078470>] ? __init_kthread_worker+0x70/0x70 [<ffffffff819ac7dc>] ret_from_fork+0x7c/0xb0 [<ffffffff81078470>] ? __init_kthread_worker+0x70/0x70 Code: a5 01 00 a0 31 d2 31 f6 48 c7 c7 e0 84 e2 81 e8 f4 91 0a e1 48 8b 43 60 48 c7 c2 a5 01 00 a0 be 01 00 00 00 48 c7 c7 e0 84 e2 81 <48> 8b 98 10 07 00 00 e8 91 8f 0a e1 e8 3c 4e 07 e1 48 83 c4 18 RIP [<ffffffffa00001f3>] rpc_net_ns+0x53/0x70 [sunrpc] RSP <ffff88003c385ab8> ---[ end trace ce5e3f2a85c100c0 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
