From d9d29a29669f96903d9950bb881c2a393fd33849 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 6 Jun 2005 13:36:11 -0700 Subject: [PATCH] [PATCH] namei fixes (15/19) Getting rid of sloppy logics: a) in do_follow_link() we have the wrong vfsmount dropped if our symlink had been mounted on something. Currently it worls only because we never get such situation (modulo filesystem playing dirty tricks on us). And it obfuscates already convoluted logics... b) same goes for open_namei(). c) in __link_path_walk() we have another "it should never happen" sloppiness - out_dput: there does double-free on underlying vfsmount and leaks the covering one if we hit it just after crossing a mountpoint. Again, wrong vfsmount getting dropped. d) another too-early-mntput() race - in do_follow_mount() we need to postpone conditional mntput(path->mnt) until after dput(path->dentry). Again, this one happens only in it-currently-never-happens-unless-some-fs-plays-dirty scenario... Signed-off-by: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/namei.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 411bb3243c36..6a884682b0a7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -544,15 +544,15 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd) current->total_link_count++; nd->depth++; if (path->mnt != nd->mnt) - mntput(nd->mnt); + mntput(path->mnt); err = __do_follow_link(path, nd); current->link_count--; nd->depth--; return err; loop: - if (path->mnt != nd->mnt) - mntput(nd->mnt); dput(path->dentry); + if (path->mnt != nd->mnt) + mntput(path->mnt); path_release(nd); return err; } @@ -906,7 +906,7 @@ return_base: out_dput: dput(next.dentry); if (nd->mnt != next.mnt) - mntput(nd->mnt); + mntput(next.mnt); break; } path_release(nd); @@ -1551,8 +1551,7 @@ do_link: if (error) goto exit_dput; if (nd->mnt != path.mnt) - mntput(nd->mnt); - nd->mnt = path.mnt; + mntput(path.mnt); error = __do_follow_link(&path, nd); if (error) return error; -- 2.39.2