* Issue in nfs-utils 1.2.3
@ 2011-01-12 11:31 sdrb
2011-01-12 13:51 ` sdrb
0 siblings, 1 reply; 5+ messages in thread
From: sdrb @ 2011-01-12 11:31 UTC (permalink / raw)
To: linux-nfs
Hello,
Recently I tried to upgrade nfs-utils to the newest nfs-utils 1.2.3.
During tests I noticed that in some circumstances rpc.mountd
crashes with segmentation fault.
I'm testing it with 2.6.36 linux kernel.
Configuration of nfs-server:
server# cat /etc/exports
/export *(rw)
/tmp/nfs *(rw)
The scenario how to reproduce the issue:
server# rpc.mountd -F -d all
server# showmount -a 127.0.0.1
host# umount /mnt/nfs2 ; mount -t nfs server:/tmp/nfs /mnt/nfs2 -o
nfsvers=3,nolock
server# showmount -a 127.0.0.1
and after spawning showmount for the second time I got two segmentation
faults: at showmount and at rpc.mountd.
Here is output from rpc.mountd:
rpc.mountd: Received DUMP request from 127.0.0.1
rpc.mountd: Received NULL request from host
rpc.mountd: Received UMNT(/tmp/nfs) request from host
rpc.mountd: authenticated unmount request from host:844 for /tmp/nfs
(/tmp/nfs)
rpc.mountd: Received NULL request from host
rpc.mountd: Received NULL request from host
rpc.mountd: Received MNT3(/tmp/nfs) request from host
rpc.mountd: authenticated mount request from host:729 for /tmp/nfs
(/tmp/nfs)
rpc.mountd: nfsd_fh: inbuf '* 7
\x0ab4100000000000dd2efb04e753f0980000000000000000'
rpc.mountd: nfsd_fh: found 0x1f13380 path /tmp/nfs
rpc.mountd: Received DUMP request from 127.0.0.1
Segmentation fault
.
To gather more info I run rpc.mountd in gdb:
Starting program: /usr/sbin/rpc.mountd -F
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b6f7a2 in xdr_string_internal () from /lib64/libc.so.6
#0 0x00007ffff7b6f7a2 in xdr_string_internal () from /lib64/libc.so.6
#1 0x0000000000409eee in xdr_name (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:83
#2 0x0000000000409ff9 in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b530) at mount_xdr.c:103
#3 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#4 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#5 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#6 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b590) at mount_xdr.c:107
#7 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#8 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#9 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#10 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b470) at mount_xdr.c:107
#11 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#12 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#13 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#14 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b4d0) at mount_xdr.c:107
#15 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#16 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#17 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#18 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b530) at mount_xdr.c:107
#19 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#20 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#21 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#22 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b590) at mount_xdr.c:107
#23 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#24 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#25 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#26 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b470) at mount_xdr.c:107
#27 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#28 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#29 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#30 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b4d0) at mount_xdr.c:107
#31 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#32 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#33 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#34 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b530) at mount_xdr.c:107
#35 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
#36 0x00007ffff7b70de1 in xdr_pointer () from /lib64/libc.so.6
#37 0x0000000000409ed3 in xdr_mountlist (xdrs=<value optimized out>,
objp=<value optimized out>) at mount_xdr.c:93
#38 0x000000000040a02c in xdr_mountbody (xdrs=0x63afd0,
objp=0x63b590) at mount_xdr.c:107
#39 0x00007ffff7b70e20 in xdr_reference_internal () from /lib64/libc.so.6
(...)
Seems like two procedures (xdr_mountlist and xdr_mountbody) call one
another infinitely until they fill the stack completely and then
segfault occures.
Is it known problem?
Maybe I misconfigured or missed something?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Issue in nfs-utils 1.2.3
2011-01-12 11:31 Issue in nfs-utils 1.2.3 sdrb
@ 2011-01-12 13:51 ` sdrb
2011-01-12 16:04 ` J. Bruce Fields
0 siblings, 1 reply; 5+ messages in thread
From: sdrb @ 2011-01-12 13:51 UTC (permalink / raw)
To: linux-nfs
[-- Attachment #1: Type: text/plain, Size: 2291 bytes --]
On 01/12/2011 12:31 PM, sdrb wrote:
> Hello,
>
>
> Recently I tried to upgrade nfs-utils to the newest nfs-utils 1.2.3.
> During tests I noticed that in some circumstances rpc.mountd
> crashes with segmentation fault.
> I'm testing it with 2.6.36 linux kernel.
>
>
> Configuration of nfs-server:
>
> server# cat /etc/exports
> /export *(rw)
> /tmp/nfs *(rw)
>
>
> The scenario how to reproduce the issue:
>
> server# rpc.mountd -F -d all
> server# showmount -a 127.0.0.1
> host# umount /mnt/nfs2 ; mount -t nfs server:/tmp/nfs /mnt/nfs2 -o
> nfsvers=3,nolock
> server# showmount -a 127.0.0.1
>
>
> and after spawning showmount for the second time I got two segmentation
> faults: at showmount and at rpc.mountd.
>
> Here is output from rpc.mountd:
> rpc.mountd: Received DUMP request from 127.0.0.1
> rpc.mountd: Received NULL request from host
> rpc.mountd: Received UMNT(/tmp/nfs) request from host
> rpc.mountd: authenticated unmount request from host:844 for /tmp/nfs
> (/tmp/nfs)
> rpc.mountd: Received NULL request from host
> rpc.mountd: Received NULL request from host
> rpc.mountd: Received MNT3(/tmp/nfs) request from host
> rpc.mountd: authenticated mount request from host:729 for /tmp/nfs
> (/tmp/nfs)
> rpc.mountd: nfsd_fh: inbuf '* 7
> \x0ab4100000000000dd2efb04e753f0980000000000000000'
> rpc.mountd: nfsd_fh: found 0x1f13380 path /tmp/nfs
> rpc.mountd: Received DUMP request from 127.0.0.1
> Segmentation fault
> .
>
>
> To gather more info I run rpc.mountd in gdb:
>
>
> Starting program: /usr/sbin/rpc.mountd -F
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x00007ffff7b6f7a2 in xdr_string_internal () from /lib64/libc.so.6
>
> #0 0x00007ffff7b6f7a2 in xdr_string_internal () from /lib64/libc.so.6
> #1 0x0000000000409eee in xdr_name (xdrs=<value optimized out>,
> objp=<value optimized out>) at mount_xdr.c:83
> (...)
>
> Seems like two procedures (xdr_mountlist and xdr_mountbody) call one
> another infinitely until they fill the stack completely and then
> segfault occures.
>
> Is it known problem?
> Maybe I misconfigured or missed something?
I've investigated a little the sources and I noticed that probably there
should be some pointer NULL-ed in mountlist_list() procedure like in
patch I've attached.
Anyone can confirm that such a fix is ok?
[-- Attachment #2: d1.diff --]
[-- Type: text/x-patch, Size: 422 bytes --]
diff -rNup nfs-utils-1.2.3_orig/utils/mountd/rmtab.c nfs-utils-1.2.3/utils/mountd/rmtab.c
--- nfs-utils-1.2.3/utils/mountd/rmtab.c 2010-09-28 14:24:16.000000000 +0200
+++ nfs-utils-1.2.3/utils/mountd/rmtab.c 2011-01-12 14:44:22.320000000 +0100
@@ -205,6 +205,7 @@ mountlist_list(void)
}
if (stb.st_mtime != last_mtime) {
mountlist_freeall(mlist);
+ mlist=NULL;
last_mtime = stb.st_mtime;
setrmtabent("r");
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: Issue in nfs-utils 1.2.3
2011-01-12 13:51 ` sdrb
@ 2011-01-12 16:04 ` J. Bruce Fields
2011-01-13 15:47 ` Chuck Lever
0 siblings, 1 reply; 5+ messages in thread
From: J. Bruce Fields @ 2011-01-12 16:04 UTC (permalink / raw)
To: sdrb; +Cc: linux-nfs, steved, chuck.lever
On Wed, Jan 12, 2011 at 02:51:20PM +0100, sdrb wrote:
> I've investigated a little the sources and I noticed that probably
> there should be some pointer NULL-ed in mountlist_list() procedure
> like in patch I've attached.
>
> Anyone can confirm that such a fix is ok?
Thanks for the report.
I haven't tried to verify that it could cause the backtrace you saw, but
clearly mlist is used after that mountlist_freeall(mlist), so your patch
is necessary.
Looks like this was introduced with a8348c2c4 "mountd: Add
mountlist_freeall()".
--b.
> diff -rNup nfs-utils-1.2.3_orig/utils/mountd/rmtab.c nfs-utils-1.2.3/utils/mountd/rmtab.c
> --- nfs-utils-1.2.3/utils/mountd/rmtab.c 2010-09-28 14:24:16.000000000 +0200
> +++ nfs-utils-1.2.3/utils/mountd/rmtab.c 2011-01-12 14:44:22.320000000 +0100
> @@ -205,6 +205,7 @@ mountlist_list(void)
> }
> if (stb.st_mtime != last_mtime) {
> mountlist_freeall(mlist);
> + mlist=NULL;
> last_mtime = stb.st_mtime;
>
> setrmtabent("r");
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: Issue in nfs-utils 1.2.3
2011-01-12 16:04 ` J. Bruce Fields
@ 2011-01-13 15:47 ` Chuck Lever
2011-01-13 15:52 ` J. Bruce Fields
0 siblings, 1 reply; 5+ messages in thread
From: Chuck Lever @ 2011-01-13 15:47 UTC (permalink / raw)
To: J. Bruce Fields, sdrb; +Cc: Linux NFS Mailing List, Steve Dickson
On Jan 12, 2011, at 11:04 AM, J. Bruce Fields wrote:
> On Wed, Jan 12, 2011 at 02:51:20PM +0100, sdrb wrote:
>> I've investigated a little the sources and I noticed that probably
>> there should be some pointer NULL-ed in mountlist_list() procedure
>> like in patch I've attached.
>>
>> Anyone can confirm that such a fix is ok?
>
> Thanks for the report.
>
> I haven't tried to verify that it could cause the backtrace you saw, but
> clearly mlist is used after that mountlist_freeall(mlist), so your patch
> is necessary.
>
> Looks like this was introduced with a8348c2c4 "mountd: Add
> mountlist_freeall()".
Is your theory that the introduction of a function call ( mountlist_freeall() ) hides the side-effects of that while loop, leaving the mlist variable in the mountlist_list() scope pointing at freed memory?
> --b.
>
>> diff -rNup nfs-utils-1.2.3_orig/utils/mountd/rmtab.c nfs-utils-1.2.3/utils/mountd/rmtab.c
>> --- nfs-utils-1.2.3/utils/mountd/rmtab.c 2010-09-28 14:24:16.000000000 +0200
>> +++ nfs-utils-1.2.3/utils/mountd/rmtab.c 2011-01-12 14:44:22.320000000 +0100
>> @@ -205,6 +205,7 @@ mountlist_list(void)
>> }
>> if (stb.st_mtime != last_mtime) {
>> mountlist_freeall(mlist);
>> + mlist=NULL;
Nit: Please use white space conventions which match the rest of the file (single blanks around "=").
>> last_mtime = stb.st_mtime;
>>
>> setrmtabent("r");
>
--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: Issue in nfs-utils 1.2.3
2011-01-13 15:47 ` Chuck Lever
@ 2011-01-13 15:52 ` J. Bruce Fields
0 siblings, 0 replies; 5+ messages in thread
From: J. Bruce Fields @ 2011-01-13 15:52 UTC (permalink / raw)
To: Chuck Lever; +Cc: sdrb, Linux NFS Mailing List, Steve Dickson
On Thu, Jan 13, 2011 at 10:47:42AM -0500, Chuck Lever wrote:
>
> On Jan 12, 2011, at 11:04 AM, J. Bruce Fields wrote:
>
> > On Wed, Jan 12, 2011 at 02:51:20PM +0100, sdrb wrote:
> >> I've investigated a little the sources and I noticed that probably
> >> there should be some pointer NULL-ed in mountlist_list() procedure
> >> like in patch I've attached.
> >>
> >> Anyone can confirm that such a fix is ok?
> >
> > Thanks for the report.
> >
> > I haven't tried to verify that it could cause the backtrace you saw, but
> > clearly mlist is used after that mountlist_freeall(mlist), so your patch
> > is necessary.
> >
> > Looks like this was introduced with a8348c2c4 "mountd: Add
> > mountlist_freeall()".
>
> Is your theory that the introduction of a function call ( mountlist_freeall() ) hides the side-effects of that while loop, leaving the mlist variable in the mountlist_list() scope pointing at freed memory?
Yup.--b.
>
> > --b.
> >
> >> diff -rNup nfs-utils-1.2.3_orig/utils/mountd/rmtab.c nfs-utils-1.2.3/utils/mountd/rmtab.c
> >> --- nfs-utils-1.2.3/utils/mountd/rmtab.c 2010-09-28 14:24:16.000000000 +0200
> >> +++ nfs-utils-1.2.3/utils/mountd/rmtab.c 2011-01-12 14:44:22.320000000 +0100
> >> @@ -205,6 +205,7 @@ mountlist_list(void)
> >> }
> >> if (stb.st_mtime != last_mtime) {
> >> mountlist_freeall(mlist);
> >> + mlist=NULL;
>
> Nit: Please use white space conventions which match the rest of the file (single blanks around "=").
>
> >> last_mtime = stb.st_mtime;
> >>
> >> setrmtabent("r");
> >
>
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
>
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
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2011-01-12 11:31 Issue in nfs-utils 1.2.3 sdrb
2011-01-12 13:51 ` sdrb
2011-01-12 16:04 ` J. Bruce Fields
2011-01-13 15:47 ` Chuck Lever
2011-01-13 15:52 ` J. Bruce Fields
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