From e9cc6c234bfe414ef36f484e3ad8be621854c440 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 2 Jan 2008 13:28:57 -0500 Subject: [PATCH] NFS: Fix a possible Oops in fs/nfs/super.c Sigh... commit 4584f520e1f773082ef44ff4f8969a5d992b16ec (NFS: Fix NFS mountpoint crossing...) had a slight flaw: server can be NULL if sget() returned an existing superblock. Fix the fix by dereferencing s->s_fs_info. Thanks to Coverity/Adrian Bunk and Frank Filz for spotting the bug. (See http://bugzilla.kernel.org/show_bug.cgi?id=9647) Also add in the same namespace Oops fix for NFSv4 in both the mountpoint crossing case, and the referral case. Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index ea92920..0b0c72a 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1475,7 +1475,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags, error = PTR_ERR(mntroot); goto error_splat_super; } - if (mntroot->d_inode->i_op != server->nfs_client->rpc_ops->dir_inode_ops) { + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { dput(mntroot); error = -ESTALE; goto error_splat_super; @@ -1826,6 +1826,11 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags, error = PTR_ERR(mntroot); goto error_splat_super; } + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { + dput(mntroot); + error = -ESTALE; + goto error_splat_super; + } s->s_flags |= MS_ACTIVE; mnt->mnt_sb = s; @@ -1900,6 +1905,11 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags, error = PTR_ERR(mntroot); goto error_splat_super; } + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { + dput(mntroot); + error = -ESTALE; + goto error_splat_super; + } s->s_flags |= MS_ACTIVE; mnt->mnt_sb = s; -- 2.7.4