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| author | Aleksa Sarai <cyphar@cyphar.com> | 2019-12-06 17:13:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-05 18:42:20 +0300 |
| commit | 94b4120facdd85e1849caf31b44992182222dffd (patch) | |
| tree | 1d7df6ec560df00bfec949d71b7fff254ae24371 | |
| parent | c5521f96a745379079ef07bcf3d3133d6740c4dd (diff) | |
| download | linux-94b4120facdd85e1849caf31b44992182222dffd.tar.xz | |
namei: only return -ECHILD from follow_dotdot_rcu()
commit 2b98149c2377bff12be5dd3ce02ae0506e2dd613 upstream.
It's over-zealous to return hard errors under RCU-walk here, given that
a REF-walk will be triggered for all other cases handling ".." under
RCU.
The original purpose of this check was to ensure that if a rename occurs
such that a directory is moved outside of the bind-mount which the
resolution started in, it would be detected and blocked to avoid being
able to mess with paths outside of the bind-mount. However, triggering a
new REF-walk is just as effective a solution.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/namei.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/namei.c b/fs/namei.c index c00a7e1da4c0..327844fedf3d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1368,7 +1368,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) nd->path.dentry = parent; nd->seq = seq; if (unlikely(!path_connected(&nd->path))) - return -ENOENT; + return -ECHILD; break; } else { struct mount *mnt = real_mount(nd->path.mnt); |