From 899bf2ceb3963b04fa412d7967480578311b1bc7 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Sat, 23 Jan 2021 12:00:02 +0100 Subject: nfs: do not export idmapped mounts Prevent nfs from exporting idmapped mounts until we have ported it to support exporting idmapped mounts. Link: https://lore.kernel.org/linux-api/20210123130958.3t6kvgkl634njpsm@wittgenstein Cc: Christoph Hellwig Cc: David Howells Cc: "J. Bruce Fields" Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- fs/nfsd/export.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'fs/nfsd/export.c') diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 81e7bb12aca6..e456421f68b4 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -369,8 +369,9 @@ static struct svc_export *svc_export_update(struct svc_export *new, struct svc_export *old); static struct svc_export *svc_export_lookup(struct svc_export *); -static int check_export(struct inode *inode, int *flags, unsigned char *uuid) +static int check_export(struct path *path, int *flags, unsigned char *uuid) { + struct inode *inode = d_inode(path->dentry); /* * We currently export only dirs, regular files, and (for v4 @@ -394,6 +395,7 @@ static int check_export(struct inode *inode, int *flags, unsigned char *uuid) * or an FSID number (so NFSEXP_FSID or ->uuid is needed). * 2: We must be able to find an inode from a filehandle. * This means that s_export_op must be set. + * 3: We must not currently be on an idmapped mount. */ if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) && !(*flags & NFSEXP_FSID) && @@ -408,6 +410,11 @@ static int check_export(struct inode *inode, int *flags, unsigned char *uuid) return -EINVAL; } + if (mnt_user_ns(path->mnt) != &init_user_ns) { + dprintk("exp_export: export of idmapped mounts not yet supported.\n"); + return -EINVAL; + } + if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK && !(*flags & NFSEXP_NOSUBTREECHECK)) { dprintk("%s: %s does not support subtree checking!\n", @@ -636,8 +643,7 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) goto out4; } - err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags, - exp.ex_uuid); + err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid); if (err) goto out4; /* -- cgit v1.2.3