From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751015AbWHIP1h (ORCPT ); Wed, 9 Aug 2006 11:27:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751017AbWHIP1g (ORCPT ); Wed, 9 Aug 2006 11:27:36 -0400 Received: from smtp-out.google.com ([216.239.45.12]:6456 "EHLO smtp-out.google.com") by vger.kernel.org with ESMTP id S1751015AbWHIP1f (ORCPT ); Wed, 9 Aug 2006 11:27:35 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=vce9GxggxviqhPQTHv1rUBnR+Ie76R4c9eDOkVYkqD9xljqSGjxibRJsE3haCz2Np tcY+Hf2HPEQJIY9pguN0w== Message-ID: Date: Wed, 9 Aug 2006 11:27:21 -0400 From: "Alex Polvi" To: "Trond Myklebust" Subject: [PATCHv2] sunrpc/auth_gss: NULL pointer deref in gss_pipe_release() Cc: linux-kernel@vger.kernel.org In-Reply-To: <1154378242.13744.14.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1154378242.13744.14.camel@localhost> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 7/31/06, Trond Myklebust wrote: > On Mon, 2006-07-31 at 10:50 -0400, Alex Polvi wrote: > > Proposed (trivial) patch to fix a NULL pointer deref in > > gss_pipe_release(). While this does seem to fix the problem, I'm not > > entirely sure it is the correct place to handle the NULL pointer. > > > > Included below is the script I used to recreate the problem, the oops, > > and the patch. > > Sorry, but that is not the correct fix. The problem here is rather that > something is causing us to call rpc_close_pipes() on the file after the > call to gss_destroy(). That is supposed to be illegal. Since rpc_rmdir can potentially call rpc_pipe_release, here is a patch to make sure it is not called after rpcauth_destroy (which calls gss_destroy)! Signed-off-by: Alex Polvi -- diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index d6409e7..d2ff886 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -312,16 +312,16 @@ rpc_destroy_client(struct rpc_clnt *clnt dprintk("RPC: destroying %s client for %s\n", clnt->cl_protname, clnt->cl_server); - if (clnt->cl_auth) { - rpcauth_destroy(clnt->cl_auth); - clnt->cl_auth = NULL; - } if (clnt->cl_parent != clnt) { rpc_destroy_client(clnt->cl_parent); goto out_free; } if (clnt->cl_pathname[0]) rpc_rmdir(clnt->cl_pathname); + if (clnt->cl_auth) { + rpcauth_destroy(clnt->cl_auth); + clnt->cl_auth = NULL; + } if (clnt->cl_xprt) { xprt_destroy(clnt->cl_xprt); clnt->cl_xprt = NULL; > > polvi@return:~/sysops/experimental/polvi$ cat oopsmynfs.sh > > #!/bin/bash > > > > cd / # make sure we are not in the dir > > > > PROG=${0##*/} > > > > function usage { > > cat < > usage: $PROG /nfs/path/ > > > > will oops sunrpc using the nfs host that serves /nfs/path/ > > EOF > > exit 1 > > } > > > > DIR=$1 > > > > [ -d "$DIR" ] || usage > > > > sudo umount $DIR 2> /dev/null # just house-keeping... > > > > sudo mount -o sec=krb5 randomfiler:/vol/to/some/share $DIR # must use krb5 > > > > # with out this ls the cd below will say permission denied and not > > hang after the > > # nfs server has been turned off. It has something to do with stat64 > > returning EACCES > > ls $DIR > /dev/null > > > > echo "Make the nfs server unusable by the client (turn off nfs, iptables, etc)." > > read -p "press enter when ready" > > > > # if the echo is hit, this script failed to oops sunrpc > > (cd $DIR/. ; echo "will not cause an oops") & # this should hang > > > > sudo umount -l $DIR > > > > echo "Turn the nfs server back on and watch for the oops. Should not > > take more then 10s" > > > > > > [ 204.385339] net/sunrpc/rpc_pipe.c: rpc_lookup_parent failed to find > > path /nfs/clnt4/krb5 > > [ 204.385427] BUG: unable to handle kernel NULL pointer dereference > > at virtual address 0000006c > > [ 204.385554] printing eip: > > [ 204.385595] c01d2322 > > [ 204.385678] *pde = 00000000 > > [ 204.385719] Oops: 0000 [#1] > > [ 204.385781] SMP > > [ 204.385875] Modules linked in: des binfmt_misc autofs4 video button > > battery ac nfs lockd af_packet sg sr_mod pcspkr rtc psm > > > > > > ouse mousedev ide_disk ide_cd cdrom > > rpcsec_gss_krb5 auth_rpcgss sunrpc ext3 jbd mbcache thermal processor > > fan tg3 sd_mod ide_g > > > > > > eneric ata_piix libata scsi_mod generic ide_core unix > > [ 204.387417] CPU: 0 > > [ 204.387418] EIP: 0060:[] Not tainted VLI > > [ 204.387419] EFLAGS: 00010292 (2.6.18-rc2-git #1) > > [ 204.387538] EIP is at _raw_spin_lock+0x12/0x170 > > [ 204.387578] eax: 00000068 ebx: 00000068 ecx: f7157d3c edx: f7157d3c > > [ 204.387621] esi: 00000068 edi: 00000000 ebp: f7157d00 esp: f7157cdc > > [ 204.387664] ds: 007b es: 007b ss: 0068 > > [ 204.387704] Process oopsmynfs.sh (pid: 6114, ti=f7156000 > > task=dffb5aa0 task.ti=f7156000) > > [ 204.387748] Stack: dffb5aa0 f7157d1c c029ee7d f7157cfc f7156000 > > f7156000 f73acd00 00000068 > > [ 204.388040] 00000000 f7157d0c c029ff7e 00000068 f7157d24 > > f88d82cf f73acd00 f73acd00 > > [ 204.388332] f73acecc f88e1554 f7157d50 f8cbd6a9 f73acd00 > > f7288460 f73acd80 f73acd70 > > [ 204.388625] Call Trace: > > [ 204.388868] [] _spin_lock+0xe/0x10 > > [ 204.388997] [] gss_pipe_release+0x1f/0x70 [auth_rpcgss] > > [ 204.389075] [] rpc_close_pipes+0xe9/0x130 [sunrpc] > > [ 204.389173] [] rpc_depopulate+0xff/0x140 [sunrpc] > > [ 204.389267] [] rpc_rmdir+0x6d/0xa0 [sunrpc] > > [ 204.389360] [] rpc_destroy_client+0xde/0x110 [sunrpc] > > [ 204.389443] [] rpc_destroy_client+0x61/0x110 [sunrpc] > > [ 204.389524] [] rpc_shutdown_client+0xb7/0x120 [sunrpc] > > [ 204.389605] [] nfs_kill_super+0x3b/0x90 [nfs] > > [ 204.389692] [] deactivate_super+0x81/0xa0 > > [ 204.389858] [] mntput_no_expire+0x52/0x90 > > [ 204.390039] [] path_release+0x2a/0x30 > > [ 204.390211] [] vfs_stat_fd+0x4b/0x60 > > [ 204.390378] [] vfs_stat+0x20/0x30 > > [ 204.390545] [] sys_stat64+0x19/0x30 > > [ 204.390712] [] sysenter_past_esp+0x56/0x79 > > [ 204.390787] [] 0xb7fff410 > > [ 204.390854] Code: 2b c0 89 f8 e8 00 fe ff ff e9 14 ff ff ff 8d 74 > > 26 00 8d bc 27 00 00 00 00 55 89 e5 83 ec 24 89 5d f4 8b > > > > > > 5d 08 89 75 f8 89 7d fc <81> 7b > > 04 ad 4e ad de 75 4c 89 e0 25 00 e0 ff ff 8b 00 39 43 0c > > [ 204.392662] EIP: [] _raw_spin_lock+0x12/0x170 SS:ESP 0068:f7157cdc > > > > Signed-off-by: Alex Polvi > > --- > > diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c > > index 4a9aa93..2db3bd1 100644 > > --- a/net/sunrpc/auth_gss/auth_gss.c > > +++ b/net/sunrpc/auth_gss/auth_gss.c > > @@ -607,6 +607,9 @@ gss_pipe_release(struct inode *inode) > > struct rpc_auth *auth; > > struct gss_auth *gss_auth; > > > > + if (rpci->ops == NULL) > > + return; > > + > > clnt = rpci->private; > > auth = clnt->cl_auth; > > gss_auth = container_of(auth, struct gss_auth, rpc_auth); > > - > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > >