Hi-
> On Dec 21, 2021, at 1:55 PM, Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> wrote:
>
> Pointer nf can be NULL. It should be validated before dereferencing it.
>
> Fixes: 8628027ba8 ("nfs: block notification on fs with its own ->lock")
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Thanks. To avoid confusion I've squashed this into 8628027 and
refreshed my for-next branch.
Btw, b4 complained about collabora.com's DKIM:
[cel@bazille linux]$ b4 am https://lore.kernel.org/linux-nfs/YcIjJ4jN3ax1rqaE@debian-BULLSEYE-live-builder-AMD64/raw
Grabbing thread from lore.kernel.org/linux-nfs/YcIjJ4jN3ax1rqaE%40debian-BULLSEYE-live-builder-AMD64/t.mbox.gz
Analyzing 1 messages in the thread
Checking attestation on all messages, may take a moment...
---
✗ [PATCH] nfs: check nf pointer for validity before use
---
✗ BADSIG: DKIM/collabora.com
---
Total patches: 1
---
Link: https://lore.kernel.org/r/YcIjJ4jN3ax1rqaE@debian-BULLSEYE-live-builder-AMD64
Base: not specified
git am ./20211221_usama_anjum_nfs_check_nf_pointer_for_validity_before_use.mbx
[cel@bazille linux]$
The patch is obviously correct, so I applied it despite the
attestation failure.
> ---
> fs/nfsd/nfs4state.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index a526d4183348..bdd30988e615 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -6947,6 +6947,11 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> goto out;
> }
>
> + if (!nf) {
> + status = nfserr_openmode;
> + goto out;
> + }
> +
> /*
> * Most filesystems with their own ->lock operations will block
> * the nfsd thread waiting to acquire the lock. That leads to
> @@ -6957,11 +6962,6 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> if (nf->nf_file->f_op->lock)
> fl_flags &= ~FL_SLEEP;
>
> - if (!nf) {
> - status = nfserr_openmode;
> - goto out;
> - }
> -
> nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn);
> if (!nbl) {
> dprintk("NFSD: %s: unable to allocate block!\n", __func__);
> --
> 2.30.2
>
--
Chuck Lever
