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SubjectRe: [PATCH] nfsd: wrong index used in inner loop


J. Bruce Fields:
> On Tue, Mar 08, 2011 at 10:32:26PM +0100, roel wrote:
>> Index i was already used in the outer loop
>>
>> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
>> ---
>> fs/nfsd/nfs4xdr.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> Not 100% sure this one is needed but it looks suspicious.
>
> Looks bad to me, thanks.
>
> nfsd4_decode_create_session should probably really be broken up a little
> bit; if it wasn't so long this would have been more obvious.
>
> I'll see if I can slip this into 2.6.38 with a couple other last-minute
> patches.... Otherwise, it'll be in 2.6.39.
>
> --b.
>
>> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
>> index 1275b86..615f0a9 100644
>> --- a/fs/nfsd/nfs4xdr.c
>> +++ b/fs/nfsd/nfs4xdr.c
>> @@ -1142,7 +1142,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
>>
>> u32 dummy;
>> char *machine_name;
>> - int i;
>> + int i, j;
>> int nr_secflavs;
>>
>> READ_BUF(16);
>> @@ -1215,7 +1215,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
>> READ_BUF(4);
>> READ32(dummy);
>> READ_BUF(dummy * 4);
>> - for (i = 0; i < dummy; ++i)
>> + for (j = 0; j < dummy; ++j)
>> READ32(dummy);

We must not use dummy for index here.
After the first index, READ32(dummy) will change dummy!!!!

The following patch fix this problem.

--
thanks,
Mi Jinlong
============================================================

We must not use dummy for index.
After the first index, READ32(dummy) will change dummy!!!!

Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
---
fs/nfsd/nfs4xdr.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 615f0a9..8dd70d0 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1140,7 +1140,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
{
DECODE_HEAD;

- u32 dummy;
+ u32 dummy, tmp;
char *machine_name;
int i, j;
int nr_secflavs;
@@ -1216,7 +1216,7 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
READ32(dummy);
READ_BUF(dummy * 4);
for (j = 0; j < dummy; ++j)
- READ32(dummy);
+ READ32(tmp);
break;
case RPC_AUTH_GSS:
dprintk("RPC_AUTH_GSS callback secflavor "
--
1.7.4.1



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