The patch titled
user_ns: handle file sigio
has been removed from the -mm tree. Its filename was
user_ns-handle-file-sigio.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: user_ns: handle file sigio
A process in one user namespace could set a fowner and sigio on a file in a
shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the fown_struct, and
enforcing that a process causing a signal to be sent be in the same user
namespace as the file owner.
Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx>
Cc: Herbert Poetzl <herbert@xxxxxxxxxxxx>
Cc: Kirill Korotaev <dev@xxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/fcntl.c | 13 ++++++++++---
fs/file_table.c | 2 ++
include/linux/fs.h | 1 +
include/linux/sched.h | 4 +---
include/linux/user_namespace.h | 2 +-
5 files changed, 15 insertions(+), 7 deletions(-)
diff -puN fs/fcntl.c~user_ns-handle-file-sigio fs/fcntl.c
--- a/fs/fcntl.c~user_ns-handle-file-sigio
+++ a/fs/fcntl.c
@@ -18,6 +18,7 @@
#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/rcupdate.h>
+#include <linux/user_namespace.h>
#include <asm/poll.h>
#include <asm/siginfo.h>
@@ -250,15 +251,18 @@ static int setfl(int fd, struct file * f
}
static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
- uid_t uid, uid_t euid, int force)
+ uid_t uid, uid_t euid, struct user_namespace *user_ns,
+ int force)
{
write_lock_irq(&filp->f_owner.lock);
if (force || !filp->f_owner.pid) {
put_pid(filp->f_owner.pid);
+ put_user_ns(filp->f_owner.user_ns);
filp->f_owner.pid = get_pid(pid);
filp->f_owner.pid_type = type;
filp->f_owner.uid = uid;
filp->f_owner.euid = euid;
+ filp->f_owner.user_ns = get_user_ns(user_ns);
}
write_unlock_irq(&filp->f_owner.lock);
}
@@ -272,7 +276,8 @@ int __f_setown(struct file *filp, struct
if (err)
return err;
- f_modown(filp, pid, type, current->uid, current->euid, force);
+ f_modown(filp, pid, type, current->uid, current->euid,
+ current->nsproxy->user_ns, force);
return 0;
}
EXPORT_SYMBOL(__f_setown);
@@ -298,7 +303,7 @@ EXPORT_SYMBOL(f_setown);
void f_delown(struct file *filp)
{
- f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
+ f_modown(filp, NULL, PIDTYPE_PID, 0, 0, NULL, 1);
}
pid_t f_getown(struct file *filp)
@@ -455,6 +460,8 @@ static const long band_table[NSIGPOLL] =
static inline int sigio_perm(struct task_struct *p,
struct fown_struct *fown, int sig)
{
+ if (fown->user_ns != p->nsproxy->user_ns)
+ return 0;
return (((fown->euid == 0) ||
(fown->euid == p->suid) || (fown->euid == p->uid) ||
(fown->uid == p->suid) || (fown->uid == p->uid)) &&
diff -puN fs/file_table.c~user_ns-handle-file-sigio fs/file_table.c
--- a/fs/file_table.c~user_ns-handle-file-sigio
+++ a/fs/file_table.c
@@ -21,6 +21,7 @@
#include <linux/fsnotify.h>
#include <linux/sysctl.h>
#include <linux/percpu_counter.h>
+#include <linux/user_namespace.h>
#include <asm/atomic.h>
@@ -175,6 +176,7 @@ void fastcall __fput(struct file *file)
if (file->f_mode & FMODE_WRITE)
put_write_access(inode);
put_pid(file->f_owner.pid);
+ put_user_ns(file->f_owner.user_ns);
file_kill(file);
file->f_path.dentry = NULL;
file->f_path.mnt = NULL;
diff -puN include/linux/fs.h~user_ns-handle-file-sigio include/linux/fs.h
--- a/include/linux/fs.h~user_ns-handle-file-sigio
+++ a/include/linux/fs.h
@@ -686,6 +686,7 @@ struct fown_struct {
struct pid *pid; /* pid or -pgrp where SIGIO should be sent */
enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
uid_t uid, euid; /* uid/euid of process setting the owner */
+ struct user_namespace *user_ns; /* namespace to which uid belongs */
int signum; /* posix.1b rt signal to be delivered on IO */
};
diff -puN include/linux/user_namespace.h~user_ns-handle-file-sigio include/linux/user_namespace.h
--- a/include/linux/user_namespace.h~user_ns-handle-file-sigio
+++ a/include/linux/user_namespace.h
@@ -48,7 +48,7 @@ static inline int clone_mnt_userns_permi
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
- return NULL;
+ return &init_user_ns;
}
static inline int copy_user_ns(int flags, struct task_struct *tsk)
diff -puN include/linux/sched.h~user_ns-handle-file-sigio include/linux/sched.h
--- a/include/linux/sched.h~user_ns-handle-file-sigio
+++ a/include/linux/sched.h
@@ -1611,12 +1611,10 @@ extern int cond_resched_softirq(void);
static inline int task_mnt_same_uidns(struct task_struct *tsk,
struct vfsmount *mnt)
{
- if (tsk->nsproxy == init_task.nsproxy)
+ if (mnt->mnt_user_ns == tsk->nsproxy->user_ns)
return 1;
if (mnt->mnt_flags & MNT_SHARE_NS)
return 1;
- if (mnt->mnt_user_ns == tsk->nsproxy->user_ns)
- return 1;
return 0;
}
#else
_
Patches currently in -mm which might be from serue@xxxxxxxxxx are
implement-file-posix-capabilities.patch
file-capabilities-dont-do-file-caps-if-mnt_nosuid.patch
file-capabilities-honor-secure_noroot.patch
user_ns-handle-file-sigio.patch
user-ns-implement-user-ns-unshare.patch
rename-attach_pid-to-find_attach_pid.patch
attach_pid-with-struct-pid-parameter.patch
remove-find_attach_pid.patch
statically-initialize-struct-pid-for-swapper.patch
explicitly-set-pgid-sid-of-init.patch
uts-namespace-remove-config_uts_ns.patch
integrity-service-api-and-dummy-provider-fix.patch
sysctl-move-utsname-sysctls-to-their-own-file.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file.patch
-
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