diff options
| author | Aleksa Sarai <cyphar@cyphar.com> | 2019-12-07 01:13:28 +1100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-12-08 19:09:38 -0500 |
| commit | 1bc82070fa2763bdca626fa8bde72b35f11e8960 (patch) | |
| tree | c64975083207b96e9d763e592d0ac5432c1cc97d | |
| parent | ce623f89872df4253719be71531116751eeab85f (diff) | |
| download | linux-1bc82070fa2763bdca626fa8bde72b35f11e8960.tar.bz2 | |
namei: allow nd_jump_link() to produce errors
In preparation for LOOKUP_NO_MAGICLINKS, it's necessary to add the
ability for nd_jump_link() to return an error which the corresponding
get_link() caller must propogate back up to the VFS.
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>
| -rw-r--r-- | fs/namei.c | 3 | ||||
| -rw-r--r-- | fs/proc/base.c | 3 | ||||
| -rw-r--r-- | fs/proc/namespaces.c | 14 | ||||
| -rw-r--r-- | include/linux/namei.h | 2 | ||||
| -rw-r--r-- | security/apparmor/apparmorfs.c | 6 |
5 files changed, 17 insertions, 11 deletions
diff --git a/fs/namei.c b/fs/namei.c index 17ebaac2da49..fb8a36372376 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -859,7 +859,7 @@ static int nd_jump_root(struct nameidata *nd) * Helper to directly jump to a known parsed path from ->get_link, * caller must have taken a reference to path beforehand. */ -void nd_jump_link(struct path *path) +int nd_jump_link(struct path *path) { struct nameidata *nd = current->nameidata; path_put(&nd->path); @@ -867,6 +867,7 @@ void nd_jump_link(struct path *path) nd->path = *path; nd->inode = nd->path.dentry->d_inode; nd->flags |= LOOKUP_JUMPED; + return 0; } static inline void put_link(struct nameidata *nd) diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb8..ee97dd322f3e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1626,8 +1626,7 @@ static const char *proc_pid_get_link(struct dentry *dentry, if (error) goto out; - nd_jump_link(&path); - return NULL; + error = nd_jump_link(&path); out: return ERR_PTR(error); } diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 08dd94df1a66..a8cca516f1a9 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -51,11 +51,15 @@ static const char *proc_ns_get_link(struct dentry *dentry, if (!task) return ERR_PTR(-EACCES); - if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { - error = ns_get_path(&ns_path, task, ns_ops); - if (!error) - nd_jump_link(&ns_path); - } + if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) + goto out; + + error = ns_get_path(&ns_path, task, ns_ops); + if (error) + goto out; + + error = nd_jump_link(&ns_path); +out: put_task_struct(task); return ERR_PTR(error); } diff --git a/include/linux/namei.h b/include/linux/namei.h index 7fe7b87a3ded..b2479cc119c6 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -69,7 +69,7 @@ extern int follow_up(struct path *); extern struct dentry *lock_rename(struct dentry *, struct dentry *); extern void unlock_rename(struct dentry *, struct dentry *); -extern void nd_jump_link(struct path *path); +extern int __must_check nd_jump_link(struct path *path); static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) { diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 09996f2552ee..7f27ce2a0113 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -2573,16 +2573,18 @@ static const char *policy_get_link(struct dentry *dentry, { struct aa_ns *ns; struct path path; + int error; if (!dentry) return ERR_PTR(-ECHILD); + ns = aa_get_current_ns(); path.mnt = mntget(aafs_mnt); path.dentry = dget(ns_dir(ns)); - nd_jump_link(&path); + error = nd_jump_link(&path); aa_put_ns(ns); - return NULL; + return ERR_PTR(error); } static int policy_readlink(struct dentry *dentry, char __user *buffer, |