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.
polvi@return:~/sysops/experimental/polvi$ cat oopsmynfs.sh
#!/bin/bash
cd / # make sure we are not in the dir
PROG=${0##*/}
function usage {
cat <<EOF
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:[<c01d2322>] 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] [<c029ff7e>] _spin_lock+0xe/0x10
[ 204.388997] [<f88d82cf>] gss_pipe_release+0x1f/0x70 [auth_rpcgss]
[ 204.389075] [<f8cbd6a9>] rpc_close_pipes+0xe9/0x130 [sunrpc]
[ 204.389173] [<f8cbd91f>] rpc_depopulate+0xff/0x140 [sunrpc]
[ 204.389267] [<f8cbda8d>] rpc_rmdir+0x6d/0xa0 [sunrpc]
[ 204.389360] [<f8cac95e>] rpc_destroy_client+0xde/0x110 [sunrpc]
[ 204.389443] [<f8cac8e1>] rpc_destroy_client+0x61/0x110 [sunrpc]
[ 204.389524] [<f8cacab7>] rpc_shutdown_client+0xb7/0x120 [sunrpc]
[ 204.389605] [<f8b2643b>] nfs_kill_super+0x3b/0x90 [nfs]
[ 204.389692] [<c016e2c1>] deactivate_super+0x81/0xa0
[ 204.389858] [<c0185522>] mntput_no_expire+0x52/0x90
[ 204.390039] [<c01770da>] path_release+0x2a/0x30
[ 204.390211] [<c01715cb>] vfs_stat_fd+0x4b/0x60
[ 204.390378] [<c0171600>] vfs_stat+0x20/0x30
[ 204.390545] [<c0171fc9>] sys_stat64+0x19/0x30
[ 204.390712] [<c0102fb1>] sysenter_past_esp+0x56/0x79
[ 204.390787] [<b7fff410>] 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: [<c01d2322>] _raw_spin_lock+0x12/0x170 SS:ESP 0068:f7157cdc
Signed-off-by: Alex Polvi <[email protected]>
---
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 [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[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]
