refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations.
Signed-off-by: Elena Reshetova <[email protected]> Signed-off-by: Hans Liljestrand <[email protected]> Signed-off-by: Kees Cook <[email protected]> Signed-off-by: David Windsor <[email protected]> --- fs/nfs/client.c | 12 ++++++------ fs/nfs/filelayout/filelayout.c | 12 ++++++------ fs/nfs/flexfilelayout/flexfilelayout.c | 12 ++++++------ fs/nfs/nfs4client.c | 16 ++++++++-------- fs/nfs/nfs4proc.c | 12 ++++++------ fs/nfs/nfs4state.c | 6 +++--- include/linux/nfs_fs_sb.h | 3 ++- 7 files changed, 37 insertions(+), 36 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 91a8d61..6c67d2e 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -163,7 +163,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) clp->rpc_ops = clp->cl_nfs_mod->rpc_ops; - atomic_set(&clp->cl_count, 1); + refcount_set(&clp->cl_count, 1); clp->cl_cons_state = NFS_CS_INITING; memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen); @@ -271,10 +271,10 @@ void nfs_put_client(struct nfs_client *clp) if (!clp) return; - dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count)); + dprintk("--> nfs_put_client({%d})\n", refcount_read(&clp->cl_count)); nn = net_generic(clp->cl_net, nfs_net_id); - if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) { + if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) { list_del(&clp->cl_share_link); nfs_cb_idr_remove_locked(clp); spin_unlock(&nn->nfs_client_lock); @@ -319,7 +319,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat sap)) continue; - atomic_inc(&clp->cl_count); + refcount_inc(&clp->cl_count); return clp; } return NULL; @@ -1029,7 +1029,7 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source, /* Copy data from the source */ server->nfs_client = source->nfs_client; server->destroy = source->destroy; - atomic_inc(&server->nfs_client->cl_count); + refcount_inc(&server->nfs_client->cl_count); nfs_server_copy_userdata(server, source); server->fsid = fattr->fsid; @@ -1195,7 +1195,7 @@ static int nfs_server_list_show(struct seq_file *m, void *v) clp->rpc_ops->version, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT), - atomic_read(&clp->cl_count), + refcount_read(&clp->cl_count), clp->cl_hostname); rcu_read_unlock(); diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c index 18f98e0..526bd6e 100644 --- a/fs/nfs/filelayout/filelayout.c +++ b/fs/nfs/filelayout/filelayout.c @@ -498,10 +498,10 @@ filelayout_read_pagelist(struct nfs_pgio_header *hdr) return PNFS_NOT_ATTEMPTED; dprintk("%s USE DS: %s cl_count %d\n", __func__, - ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count)); + ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count)); /* No multipath support. Use first DS */ - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); hdr->ds_clp = ds->ds_clp; hdr->ds_commit_idx = idx; fh = nfs4_fl_select_ds_fh(lseg, j); @@ -542,10 +542,10 @@ filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync) dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d\n", __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count, - offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count)); + offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count)); hdr->pgio_done_cb = filelayout_write_done_cb; - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); hdr->ds_clp = ds->ds_clp; hdr->ds_commit_idx = idx; fh = nfs4_fl_select_ds_fh(lseg, j); @@ -1038,9 +1038,9 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how) goto out_err; dprintk("%s ino %lu, how %d cl_count %d\n", __func__, - data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count)); + data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count)); data->commit_done_cb = filelayout_commit_done_cb; - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); data->ds_clp = ds->ds_clp; fh = select_ds_fh_from_commit(lseg, data->ds_commit_index); if (fh) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index 18d4c5a..341b02f 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -1771,10 +1771,10 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) vers = nfs4_ff_layout_ds_version(lseg, idx); dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__, - ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers); + ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers); hdr->pgio_done_cb = ff_layout_read_done_cb; - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); hdr->ds_clp = ds->ds_clp; fh = nfs4_ff_layout_select_ds_fh(lseg, idx); if (fh) @@ -1830,11 +1830,11 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n", __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count, - offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), + offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers); hdr->pgio_done_cb = ff_layout_write_done_cb; - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); hdr->ds_clp = ds->ds_clp; hdr->ds_commit_idx = idx; fh = nfs4_ff_layout_select_ds_fh(lseg, idx); @@ -1899,11 +1899,11 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) vers = nfs4_ff_layout_ds_version(lseg, idx); dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__, - data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count), + data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count), vers); data->commit_done_cb = ff_layout_commit_done_cb; data->cred = ds_cred; - atomic_inc(&ds->ds_clp->cl_count); + refcount_inc(&ds->ds_clp->cl_count); data->ds_clp = ds->ds_clp; fh = select_ds_fh_from_commit(lseg, data->ds_commit_index); if (fh) diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 5ae9d64..6984760 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -506,7 +506,7 @@ int nfs40_walk_client_list(struct nfs_client *new, /* If "pos" isn't marked ready, we can't trust the * remaining fields in "pos" */ if (pos->cl_cons_state > NFS_CS_READY) { - atomic_inc(&pos->cl_count); + refcount_inc(&pos->cl_count); spin_unlock(&nn->nfs_client_lock); nfs_put_client(prev); @@ -541,7 +541,7 @@ int nfs40_walk_client_list(struct nfs_client *new, * way that a SETCLIENTID_CONFIRM to pos can succeed is * if new and pos point to the same server: */ - atomic_inc(&pos->cl_count); + refcount_inc(&pos->cl_count); spin_unlock(&nn->nfs_client_lock); nfs_put_client(prev); @@ -558,7 +558,7 @@ int nfs40_walk_client_list(struct nfs_client *new, prev = NULL; *result = pos; dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n", - __func__, pos, atomic_read(&pos->cl_count)); + __func__, pos, refcount_read(&pos->cl_count)); goto out; case -ERESTARTSYS: case -ETIMEDOUT: @@ -750,7 +750,7 @@ int nfs41_walk_client_list(struct nfs_client *new, * ID and serverowner fields. Wait for CREATE_SESSION * to finish. */ if (pos->cl_cons_state > NFS_CS_READY) { - atomic_inc(&pos->cl_count); + refcount_inc(&pos->cl_count); spin_unlock(&nn->nfs_client_lock); nfs_put_client(prev); @@ -784,11 +784,11 @@ int nfs41_walk_client_list(struct nfs_client *new, if (!nfs4_match_client_owner_id(pos, new)) continue; found: - atomic_inc(&pos->cl_count); + refcount_inc(&pos->cl_count); *result = pos; status = 0; dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n", - __func__, pos, atomic_read(&pos->cl_count)); + __func__, pos, refcount_read(&pos->cl_count)); break; } @@ -820,7 +820,7 @@ nfs4_find_client_ident(struct net *net, int cb_ident) spin_lock(&nn->nfs_client_lock); clp = idr_find(&nn->cb_ident_idr, cb_ident); if (clp) - atomic_inc(&clp->cl_count); + refcount_inc(&clp->cl_count); spin_unlock(&nn->nfs_client_lock); return clp; } @@ -875,7 +875,7 @@ nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr, sid->data, NFS4_MAX_SESSIONID_LEN) != 0) continue; - atomic_inc(&clp->cl_count); + refcount_inc(&clp->cl_count); spin_unlock(&nn->nfs_client_lock); return clp; } diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 2c85c9f..7046e56 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4873,7 +4873,7 @@ static void nfs4_renew_release(void *calldata) struct nfs4_renewdata *data = calldata; struct nfs_client *clp = data->client; - if (atomic_read(&clp->cl_count) > 1) + if (refcount_read(&clp->cl_count) > 1) nfs4_schedule_state_renewal(clp); nfs_put_client(clp); kfree(data); @@ -4921,7 +4921,7 @@ static int nfs4_proc_async_renew(struct nfs_client *clp, struct rpc_cred *cred, if (renew_flags == 0) return 0; - if (!atomic_inc_not_zero(&clp->cl_count)) + if (!refcount_inc_not_zero(&clp->cl_count)) return -EIO; data = kmalloc(sizeof(*data), GFP_NOFS); if (data == NULL) @@ -7588,7 +7588,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred, struct rpc_task *task; int status = -EIO; - if (!atomic_inc_not_zero(&clp->cl_count)) + if (!refcount_inc_not_zero(&clp->cl_count)) goto out; status = -ENOMEM; @@ -8150,7 +8150,7 @@ static void nfs41_sequence_release(void *data) struct nfs4_sequence_data *calldata = data; struct nfs_client *clp = calldata->clp; - if (atomic_read(&clp->cl_count) > 1) + if (refcount_read(&clp->cl_count) > 1) nfs4_schedule_state_renewal(clp); nfs_put_client(clp); kfree(calldata); @@ -8179,7 +8179,7 @@ static void nfs41_sequence_call_done(struct rpc_task *task, void *data) trace_nfs4_sequence(clp, task->tk_status); if (task->tk_status < 0) { dprintk("%s ERROR %d\n", __func__, task->tk_status); - if (atomic_read(&clp->cl_count) == 1) + if (refcount_read(&clp->cl_count) == 1) goto out; if (nfs41_sequence_handle_errors(task, clp) == -EAGAIN) { @@ -8227,7 +8227,7 @@ static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp, .flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT, }; - if (!atomic_inc_not_zero(&clp->cl_count)) + if (!refcount_inc_not_zero(&clp->cl_count)) return ERR_PTR(-EIO); calldata = kzalloc(sizeof(*calldata), GFP_NOFS); if (calldata == NULL) { diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 347cb18..8dd2aef 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1171,7 +1171,7 @@ void nfs4_schedule_state_manager(struct nfs_client *clp) if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) return; __module_get(THIS_MODULE); - atomic_inc(&clp->cl_count); + refcount_inc(&clp->cl_count); /* The rcu_read_lock() is not strictly necessary, as the state * manager is the only thread that ever changes the rpc_xprt @@ -1263,7 +1263,7 @@ int nfs4_wait_clnt_recover(struct nfs_client *clp) might_sleep(); - atomic_inc(&clp->cl_count); + refcount_inc(&clp->cl_count); res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING, nfs_wait_bit_killable, TASK_KILLABLE); if (res) @@ -2498,7 +2498,7 @@ static void nfs4_state_manager(struct nfs_client *clp) break; if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) break; - } while (atomic_read(&clp->cl_count) > 1); + } while (refcount_read(&clp->cl_count) > 1); return; out_error: if (strlen(section)) diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index b34097c..8a2be4d 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -9,6 +9,7 @@ #include <linux/sunrpc/xprt.h> #include <linux/atomic.h> +#include <linux/refcount.h> struct nfs4_session; struct nfs_iostats; @@ -24,7 +25,7 @@ struct nfs41_impl_id; * The nfs_client identifies our client state to the server. */ struct nfs_client { - atomic_t cl_count; + refcount_t cl_count; atomic_t cl_mds_count; int cl_cons_state; /* current construction state (-ve: init error) */ #define NFS_CS_READY 0 /* ready to be used */ -- 2.7.4
