| Message ID | 20150522144702.GA126334@ubuntu-hedt (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Seth Forshee <seth.forshee@canonical.com> writes: > On Fri, May 22, 2015 at 04:23:55PM +0200, Miklos Szeredi wrote: >> On Sat, May 2, 2015 at 5:56 PM, <alexey@kurnosov.spb.ru> wrote: >> > >> > 3.10.0-229 form Scientific Linux and native 4.0.1-1 (from elrepo). >> > SL 7.1 on the host and SL 6.6 on the LXC guest. At least in 3.10 >> > the 499dcf2024092e5cce41d05599a5b51d1f92031a is present. >> > Steps to reproduce: >> > >> > On first console: >> > [root@sl7test ~]# lxc-start -n test-2 /bin/su - >> > [root@test-2 ~]# diff -u hello.py /usr/share/doc/fuse-python-0.2.1/example/hello.py >> > --- hello.py 2015-05-02 11:12:13.963093580 -0400 >> > +++ /usr/share/doc/fuse-python-0.2.1/example/hello.py 2010-04-14 18:29:21.000000000 -0400 >> > @@ -41,8 +41,6 @@ >> > class HelloFS(Fuse): >> > >> > def getattr(self, path): >> > - dic = Fuse.GetContext(self) >> > - print dic >> > st = MyStat() >> > if path == '/': >> > st.st_mode = stat.S_IFDIR | 0755 >> > [root@test-2 ~]# python hello.py -f /mnt/ >> > >> > On second console: >> > [root@test-2 ~]# echo $$ >> > 41 >> > [root@test-2 ~]# ls /mnt/ >> > hello >> > >> > Output of first console: >> > {'gid': 0, 'pid': 12083, 'uid': 0} >> >> Thanks. >> >> Digging in mailbox... There was a thread last year about adding >> support for running fuse daemon in a container: >> >> http://thread.gmane.org/gmane.linux.kernel/1811658 >> >> Not sure what happened, but no updated patches have been posted or >> maybe I just missed them. > > I haven't sent updated patches in a while. I still intend to, but I > shifted focus to first getting general support for mounts from user > namespaces into the vfs (which will give a clearer direction for some of > the concerns raised about the fuse patches). > > All of this code is available in the userns-mounts branch of > git://kernel.ubuntu.com/sforshee/linux.git, and I don't think the fuse > patches actually depend on any of the stuff that precedes them. I'm > planning to start submitting some of the earlier patches from that > branch soon, and eventually get back to resubmitting the fuse patches. > > This is about pid namespaces though, and the fuse pid namespace patch > from that series (see below) should be more or less independent of the > rest of the patches. Potentially that could be merged separately from > the user namespae stuff. [snip] > @@ -2076,7 +2077,15 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, > > fl->fl_start = ffl->start; > fl->fl_end = ffl->end; > - fl->fl_pid = ffl->pid; > + > + /* > + * Convert pid into the connection's pid namespace. If the > + * pid does not map into the namespace fl_pid will get set > + * to 0. > + */ > + rcu_read_lock(); > + fl->fl_pid = pid_vnr(find_pid_ns(ffl->pid, fc->pid_ns)); > + rcu_read_unlock(); Scratches my head. This looks wrong. I would have expected pid_nr_ns. Am I missing something reading this patch quickly? Eric -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, May 22, 2015 at 12:44:35PM -0500, Eric W. Biederman wrote: > Seth Forshee <seth.forshee@canonical.com> writes: > > > On Fri, May 22, 2015 at 04:23:55PM +0200, Miklos Szeredi wrote: > >> On Sat, May 2, 2015 at 5:56 PM, <alexey@kurnosov.spb.ru> wrote: > >> > > >> > 3.10.0-229 form Scientific Linux and native 4.0.1-1 (from elrepo). > >> > SL 7.1 on the host and SL 6.6 on the LXC guest. At least in 3.10 > >> > the 499dcf2024092e5cce41d05599a5b51d1f92031a is present. > >> > Steps to reproduce: > >> > > >> > On first console: > >> > [root@sl7test ~]# lxc-start -n test-2 /bin/su - > >> > [root@test-2 ~]# diff -u hello.py /usr/share/doc/fuse-python-0.2.1/example/hello.py > >> > --- hello.py 2015-05-02 11:12:13.963093580 -0400 > >> > +++ /usr/share/doc/fuse-python-0.2.1/example/hello.py 2010-04-14 18:29:21.000000000 -0400 > >> > @@ -41,8 +41,6 @@ > >> > class HelloFS(Fuse): > >> > > >> > def getattr(self, path): > >> > - dic = Fuse.GetContext(self) > >> > - print dic > >> > st = MyStat() > >> > if path == '/': > >> > st.st_mode = stat.S_IFDIR | 0755 > >> > [root@test-2 ~]# python hello.py -f /mnt/ > >> > > >> > On second console: > >> > [root@test-2 ~]# echo $$ > >> > 41 > >> > [root@test-2 ~]# ls /mnt/ > >> > hello > >> > > >> > Output of first console: > >> > {'gid': 0, 'pid': 12083, 'uid': 0} > >> > >> Thanks. > >> > >> Digging in mailbox... There was a thread last year about adding > >> support for running fuse daemon in a container: > >> > >> http://thread.gmane.org/gmane.linux.kernel/1811658 > >> > >> Not sure what happened, but no updated patches have been posted or > >> maybe I just missed them. > > > > I haven't sent updated patches in a while. I still intend to, but I > > shifted focus to first getting general support for mounts from user > > namespaces into the vfs (which will give a clearer direction for some of > > the concerns raised about the fuse patches). > > > > All of this code is available in the userns-mounts branch of > > git://kernel.ubuntu.com/sforshee/linux.git, and I don't think the fuse > > patches actually depend on any of the stuff that precedes them. I'm > > planning to start submitting some of the earlier patches from that > > branch soon, and eventually get back to resubmitting the fuse patches. > > > > This is about pid namespaces though, and the fuse pid namespace patch > > from that series (see below) should be more or less independent of the > > rest of the patches. Potentially that could be merged separately from > > the user namespae stuff. > > [snip] > > > @@ -2076,7 +2077,15 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, > > > > fl->fl_start = ffl->start; > > fl->fl_end = ffl->end; > > - fl->fl_pid = ffl->pid; > > + > > + /* > > + * Convert pid into the connection's pid namespace. If the > > + * pid does not map into the namespace fl_pid will get set > > + * to 0. > > + */ > > + rcu_read_lock(); > > + fl->fl_pid = pid_vnr(find_pid_ns(ffl->pid, fc->pid_ns)); > > + rcu_read_unlock(); > > Scratches my head. This looks wrong. > > I would have expected pid_nr_ns. Am I missing something reading this > patch quickly? Here we're in the context of a F_GETLK operation. We've requested the lock information from the fuse process, and ffl->pid is the pid number in that process's pid namespace so it needs to be translated into current's namespace. First we have to look up the struct pid, then pid_vnr is just a wrapper for pid_nr_ns in the current pid namespace: pid_t pid_vnr(struct pid *pid) { return pid_nr_ns(pid, task_active_pid_ns(current)); } Oh, but the comment is wrong, so maybe that's what confused you. s/connection/caller/ there and it should make more sense. Seth -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 2ee0a7376e0e..627cbdbc63a3 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -19,6 +19,7 @@ #include <linux/pipe_fs_i.h> #include <linux/swap.h> #include <linux/splice.h> +#include <linux/sched.h> MODULE_ALIAS_MISCDEV(FUSE_MINOR); MODULE_ALIAS("devname:fuse"); @@ -127,7 +128,7 @@ static void fuse_req_init_context(struct fuse_conn *fc, struct fuse_req *req) { req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid()); req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid()); - req->in.h.pid = current->pid; + req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); } void fuse_set_initialized(struct fuse_conn *fc) @@ -1124,7 +1125,8 @@ __releases(fc->lock) arg.unique = req->in.h.unique; spin_unlock(&fc->lock); - if (fc->user_ns != current_user_ns()) + if (fc->user_ns != current_user_ns() || + fc->pid_ns != task_active_pid_ns(current)) return -EIO; if (nbytes < reqsize) return -EINVAL; @@ -1178,7 +1180,8 @@ __releases(fc->lock) spin_unlock(&fc->lock); kfree(forget); - if (fc->user_ns != current_user_ns()) + if (fc->user_ns != current_user_ns() || + fc->pid_ns != task_active_pid_ns(current)) return -EIO; if (nbytes < ih.len) return -EINVAL; @@ -1218,7 +1221,8 @@ __releases(fc->lock) head = dequeue_forget(fc, max_forgets, &count); spin_unlock(&fc->lock); - if (fc->user_ns != current_user_ns()) + if (fc->user_ns != current_user_ns() || + fc->pid_ns != task_active_pid_ns(current)) return -EIO; arg.count = count; @@ -1306,7 +1310,8 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file, req->state = FUSE_REQ_READING; list_move(&req->list, &fc->io); - if (fc->user_ns != current_user_ns()) { + if (fc->user_ns != current_user_ns() || + fc->pid_ns != task_active_pid_ns(current)) { req->out.h.error = -EIO; request_end(fc, req); return -EPERM; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 5ef05b5c4cff..126b1568dc4c 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -2061,7 +2061,8 @@ static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) return generic_file_mmap(file, vma); } -static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, +static int convert_fuse_file_lock(struct fuse_conn *fc, + const struct fuse_file_lock *ffl, struct file_lock *fl) { switch (ffl->type) { @@ -2076,7 +2077,15 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, fl->fl_start = ffl->start; fl->fl_end = ffl->end; - fl->fl_pid = ffl->pid; + + /* + * Convert pid into the connection's pid namespace. If the + * pid does not map into the namespace fl_pid will get set + * to 0. + */ + rcu_read_lock(); + fl->fl_pid = pid_vnr(find_pid_ns(ffl->pid, fc->pid_ns)); + rcu_read_unlock(); break; default: @@ -2125,7 +2134,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl) args.out.args[0].value = &outarg; err = fuse_simple_request(fc, &args); if (!err) - err = convert_fuse_file_lock(&outarg.lk, fl); + err = convert_fuse_file_lock(fc, &outarg.lk, fl); return err; } @@ -2137,7 +2146,8 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) FUSE_ARGS(args); struct fuse_lk_in inarg; int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK; - pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0; + struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL; + pid_t pid_nr = pid_nr_ns(pid, fc->pid_ns); int err; if (fl->fl_lmops && fl->fl_lmops->lm_grant) { @@ -2149,7 +2159,10 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) if (fl->fl_flags & FL_CLOSE) return 0; - fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg); + if (pid && pid_nr == 0) + return -EOVERFLOW; + + fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg); err = fuse_simple_request(fc, &args); /* locking is restartable */ diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index f6eddd8a2e06..3b7a301c0999 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -23,6 +23,7 @@ #include <linux/poll.h> #include <linux/workqueue.h> #include <linux/user_namespace.h> +#include <linux/pid_namespace.h> /** Max number of pages that can be used in a single read request */ #define FUSE_MAX_PAGES_PER_REQ 32 @@ -406,6 +407,9 @@ struct fuse_conn { /** The user namespace for this mount */ struct user_namespace *user_ns; + /** The pid namespace for this mount */ + struct pid_namespace *pid_ns; + /** The fuse mount flags for this mount */ unsigned flags; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 0e2a35507f1a..d190ce2c9d8f 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -20,6 +20,7 @@ #include <linux/random.h> #include <linux/sched.h> #include <linux/exportfs.h> +#include <linux/pid_namespace.h> MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); MODULE_DESCRIPTION("Filesystem in Userspace"); @@ -627,6 +628,7 @@ void fuse_conn_init(struct fuse_conn *fc) fc->attr_version = 1; get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); fc->user_ns = get_user_ns(current_user_ns()); + fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); } EXPORT_SYMBOL_GPL(fuse_conn_init); @@ -636,6 +638,7 @@ void fuse_conn_put(struct fuse_conn *fc) if (fc->destroy_req) fuse_request_free(fc->destroy_req); put_user_ns(fc->user_ns); + put_pid_ns(fc->pid_ns); fc->release(fc); } }