[PATCH v3 1/1] NFSD: fix problems with cleanup on errors in nfsd4_copy
From: Dai Ngo <dai.ngo@oracle.com>
Date: 2023-01-31 19:12:49
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, Linus Torvalds
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 <dai.ngo@oracle.com>
---
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(©->cp_clp->async_lock); - list_del(©->copies); - spin_unlock(©->cp_clp->async_lock); + if (copy->cp_clp) { + spin_lock(©->cp_clp->async_lock); + if (!list_empty(©->copies)) + list_del_init(©->copies); + spin_unlock(©->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(©->cp_res.cb_stateid, ©->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