2023-01-31 19:12:49

by Dai Ngo

Subject: [PATCH v3 1/1] NFSD: fix problems with cleanup on errors in nfsd4_copy

When nfsd4_copy fails to allocate memory for async_copy->cp_src, or
nfs4_init_copy_state fails, it calls cleanup_async_copy to do the
cleanup for the async_copy which causes page fault since async_copy
is not yet initialized.

This patche rearranges the order of initializing the fields in
async_copy and adds checks in cleanup_async_copy to skip un-initialized
fields.

Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Fixes: 87689df69491 ("NFSD: Shrink size of struct nfsd4_copy")
Signed-off-by: Dai Ngo <[email protected]>
---
v3: replace list_del with list_del_init

fs/nfsd/nfs4proc.c | 12 ++++++++----
fs/nfsd/nfs4state.c | 5 +++--
2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 57f791899de3..5ae670807449 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1687,9 +1687,12 @@ static void cleanup_async_copy(struct nfsd4_copy *copy)
{
nfs4_free_copy_state(copy);
release_copy_files(copy);
- spin_lock(&copy->cp_clp->async_lock);
- list_del(&copy->copies);
- spin_unlock(&copy->cp_clp->async_lock);
+ if (copy->cp_clp) {
+ spin_lock(&copy->cp_clp->async_lock);
+ if (!list_empty(&copy->copies))
+ list_del_init(&copy->copies);
+ spin_unlock(&copy->cp_clp->async_lock);
+ }
nfs4_put_copy(copy);
}

@@ -1786,12 +1789,13 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
if (!async_copy)
goto out_err;
+ INIT_LIST_HEAD(&async_copy->copies);
+ refcount_set(&async_copy->refcount, 1);
async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);
if (!async_copy->cp_src)
goto out_err;
if (!nfs4_init_copy_state(nn, copy))
goto out_err;
- refcount_set(&async_copy->refcount, 1);
memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid.cs_stid,
sizeof(copy->cp_res.cb_stateid));
dup_copy_fields(copy, async_copy);
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index ace02fd0d590..c39e43742dd6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -975,7 +975,6 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,

stid->cs_stid.si_opaque.so_clid.cl_boot = (u32)nn->boot_time;
stid->cs_stid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
- stid->cs_type = cs_type;

idr_preload(GFP_KERNEL);
spin_lock(&nn->s2s_cp_lock);
@@ -986,6 +985,7 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
idr_preload_end();
if (new_id < 0)
return 0;
+ stid->cs_type = cs_type;
return 1;
}

@@ -1019,7 +1019,8 @@ void nfs4_free_copy_state(struct nfsd4_copy *copy)
{
struct nfsd_net *nn;

- WARN_ON_ONCE(copy->cp_stateid.cs_type != NFS4_COPY_STID);
+ if (copy->cp_stateid.cs_type != NFS4_COPY_STID)
+ return;
nn = net_generic(copy->cp_clp->net, nfsd_net_id);
spin_lock(&nn->s2s_cp_lock);
idr_remove(&nn->s2s_cp_stateids,
--
2.9.5

2023-01-31 19:50:52

by Jeff Layton

Subject: Re: [PATCH v3 1/1] NFSD: fix problems with cleanup on errors in nfsd4_copy

On Tue, 2023-01-31 at 11:12 -0800, Dai Ngo wrote:
> When nfsd4_copy fails to allocate memory for async_copy->cp_src, or
> nfs4_init_copy_state fails, it calls cleanup_async_copy to do the
> cleanup for the async_copy which causes page fault since async_copy
> is not yet initialized.
>
> This patche rearranges the order of initializing the fields in
> async_copy and adds checks in cleanup_async_copy to skip un-initialized
> fields.
>
> Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
> Fixes: 87689df69491 ("NFSD: Shrink size of struct nfsd4_copy")
> Signed-off-by: Dai Ngo <[email protected]>
> ---
> v3: replace list_del with list_del_init
>
> fs/nfsd/nfs4proc.c | 12 ++++++++----
> fs/nfsd/nfs4state.c | 5 +++--
> 2 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 57f791899de3..5ae670807449 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1687,9 +1687,12 @@ static void cleanup_async_copy(struct nfsd4_copy *copy)
> {
> nfs4_free_copy_state(copy);
> release_copy_files(copy);
> - spin_lock(&copy->cp_clp->async_lock);
> - list_del(&copy->copies);
> - spin_unlock(&copy->cp_clp->async_lock);
> + if (copy->cp_clp) {
> + spin_lock(&copy->cp_clp->async_lock);
> + if (!list_empty(&copy->copies))
> + list_del_init(&copy->copies);
> + spin_unlock(&copy->cp_clp->async_lock);
> + }
> nfs4_put_copy(copy);
> }
>
> @@ -1786,12 +1789,13 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
> if (!async_copy)
> goto out_err;
> + INIT_LIST_HEAD(&async_copy->copies);
> + refcount_set(&async_copy->refcount, 1);
> async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);
> if (!async_copy->cp_src)
> goto out_err;
> if (!nfs4_init_copy_state(nn, copy))
> goto out_err;
> - refcount_set(&async_copy->refcount, 1);
> memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid.cs_stid,
> sizeof(copy->cp_res.cb_stateid));
> dup_copy_fields(copy, async_copy);
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index ace02fd0d590..c39e43742dd6 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -975,7 +975,6 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
>
> stid->cs_stid.si_opaque.so_clid.cl_boot = (u32)nn->boot_time;
> stid->cs_stid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
> - stid->cs_type = cs_type;
>
> idr_preload(GFP_KERNEL);
> spin_lock(&nn->s2s_cp_lock);
> @@ -986,6 +985,7 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
> idr_preload_end();
> if (new_id < 0)
> return 0;
> + stid->cs_type = cs_type;
> return 1;
> }
>
> @@ -1019,7 +1019,8 @@ void nfs4_free_copy_state(struct nfsd4_copy *copy)
> {
> struct nfsd_net *nn;
>
> - WARN_ON_ONCE(copy->cp_stateid.cs_type != NFS4_COPY_STID);
> + if (copy->cp_stateid.cs_type != NFS4_COPY_STID)
> + return;
> nn = net_generic(copy->cp_clp->net, nfsd_net_id);
> spin_lock(&nn->s2s_cp_lock);
> idr_remove(&nn->s2s_cp_stateids,

Reviewed-by: Jeff Layton <[email protected]>