[PATCH] vfs: avoid hang caused by attempting to rmdir an invalid file system
From: Theodore Ts'o <tytso@mit.edu>
Date: 2012-05-28 17:33:42
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
If we rmdir a directory which is a hard link to '.', we will deadlock trying to grab the directory's i_mutex. Check for this condition and return EINVAL, which is what we return if the user attempts to rmdir "/foo/bar/." Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> --- fs/namei.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 0062dd1..081f872 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -2774,6 +2774,17 @@ static long do_rmdir(int dfd, const char __user *pathname) error = -ENOENT; goto exit3; } + if (nd.path.dentry->d_inode == dentry->d_inode) { + /* + * Corrupt file system where there is a symlink to + * '.'; treat it as if we are trying to rmdir '.' + * + * XXX Should we call into the low-level file system + * to request that the file system be marked corrupt? + */ + error = -EINVAL; + goto exit3; + } error = mnt_want_write(nd.path.mnt); if (error) goto exit3;
--
1.7.10.2.552.gaa3bb87