From 1cef21842ff3b6043c459b6462183e70295b5b19 Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Fri, 21 Feb 2020 15:21:38 -0500 Subject: [PATCH 1/4] NFS: Ensure the fs_context has the correct fs_type before mounting This is necessary because unless userspace explicitly requests fstype "nfs4" (either via "mount -t nfs4" or by calling the "mount.nfs4" helper directly), the fstype will default to "nfs". This was fine on older kernels because the super_block->s_type was set via mount_info->nfs_mod->nfs_fs, which was set when parsing the mount options and subsequently passed in the "type" argument of sget(). After commit f2aedb713c28 ("NFS: Add fs_context support."), sget_fc(), which has no "type" argument, is called instead. In sget_fc(), the super_block->s_type is set via fs_context->fs_type, which was set when the filesystem context was initially created. Reported-by: Patrick Steinhardt Fixes: f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker --- fs/nfs/fs_context.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c index e1b938457ab9..b616263b0eb6 100644 --- a/fs/nfs/fs_context.c +++ b/fs/nfs/fs_context.c @@ -1240,6 +1240,13 @@ static int nfs_fs_context_validate(struct fs_context *fc) } ctx->nfs_mod = nfs_mod; } + + /* Ensure the filesystem context has the correct fs_type */ + if (fc->fs_type != ctx->nfs_mod->nfs_fs) { + module_put(fc->fs_type->owner); + __module_get(ctx->nfs_mod->nfs_fs->owner); + fc->fs_type = ctx->nfs_mod->nfs_fs; + } return 0; out_no_device_name: From 1821b26a1fed8fca57a96ef87bac7a6a48e78815 Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Thu, 20 Feb 2020 08:06:20 -0500 Subject: [PATCH 2/4] NFS: Don't hard-code the fs_type when submounting Hard-coding the fstype causes "nfs4" mounts to appear as "nfs", which breaks scripts that do "umount -at nfs4". Reported-by: Patrick Steinhardt Fixes: f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker --- fs/nfs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index ad6077404947..f3ece8ed3203 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -153,7 +153,7 @@ struct vfsmount *nfs_d_automount(struct path *path) /* Open a new filesystem context, transferring parameters from the * parent superblock, including the network namespace. */ - fc = fs_context_for_submount(&nfs_fs_type, path->dentry); + fc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry); if (IS_ERR(fc)) return ERR_CAST(fc); From 75a9b9176157f3095d3099adf512b5a233addbc7 Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Tue, 25 Feb 2020 11:05:22 -0500 Subject: [PATCH 3/4] NFS: Fix leak of ctx->nfs_server.hostname If userspace passes an nfs_mount_data struct in the data argument of mount(2), then nfs23_parse_monolithic() or nfs4_parse_monolithic() will allocate memory for ctx->nfs_server.hostname. This needs to be freed in nfs_parse_source(), which also allocates memory for ctx->nfs_server.hostname, otherwise a leak will occur. Reported-by: syzbot+193c375dcddb4f345091@syzkaller.appspotmail.com Fixes: f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker --- fs/nfs/fs_context.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c index b616263b0eb6..e113fcb4bb4c 100644 --- a/fs/nfs/fs_context.c +++ b/fs/nfs/fs_context.c @@ -832,6 +832,8 @@ static int nfs_parse_source(struct fs_context *fc, if (len > maxnamlen) goto out_hostname; + kfree(ctx->nfs_server.hostname); + /* N.B. caller will free nfs_server.hostname in all cases */ ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL); if (!ctx->nfs_server.hostname) From 55dee1bc0d72877b99805e42e0205087e98b9edd Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Mon, 24 Feb 2020 16:29:32 -0500 Subject: [PATCH 4/4] nfs: add minor version to nfs_server_key for fscache An NFS client that mounts multiple exports from the same NFS server with higher NFSv4 versions disabled (i.e. 4.2) and without forcing a specific NFS version results in fscache index cookie collisions and the following messages: [ 570.004348] FS-Cache: Duplicate cookie detected Each nfs_client structure should have its own fscache index cookie, so add the minorversion to nfs_server_key. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200145 Signed-off-by: Scott Mayhew Signed-off-by: Dave Wysochanski Signed-off-by: Anna Schumaker --- fs/nfs/client.c | 1 + fs/nfs/fscache.c | 2 ++ fs/nfs/nfs4client.c | 1 - 3 files changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 989c30c98511..f1ff3076e4a4 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -153,6 +153,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) goto error_0; + clp->cl_minorversion = cl_init->minorversion; clp->cl_nfs_mod = cl_init->nfs_mod; if (!try_module_get(clp->cl_nfs_mod->owner)) goto error_dealloc; diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c index 52270bfac120..1abf126c2df4 100644 --- a/fs/nfs/fscache.c +++ b/fs/nfs/fscache.c @@ -31,6 +31,7 @@ static DEFINE_SPINLOCK(nfs_fscache_keys_lock); struct nfs_server_key { struct { uint16_t nfsversion; /* NFS protocol version */ + uint32_t minorversion; /* NFSv4 minor version */ uint16_t family; /* address family */ __be16 port; /* IP port */ } hdr; @@ -55,6 +56,7 @@ void nfs_fscache_get_client_cookie(struct nfs_client *clp) memset(&key, 0, sizeof(key)); key.hdr.nfsversion = clp->rpc_ops->version; + key.hdr.minorversion = clp->cl_minorversion; key.hdr.family = clp->cl_addr.ss_family; switch (clp->cl_addr.ss_family) { diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 0cd767e5c977..0bd77cc1f639 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -216,7 +216,6 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init) INIT_LIST_HEAD(&clp->cl_ds_clients); rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client"); clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED; - clp->cl_minorversion = cl_init->minorversion; clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion]; clp->cl_mig_gen = 1; #if IS_ENABLED(CONFIG_NFS_V4_1)