| Message ID | 20150526152138.GB4531@tucsk.suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 26, 2015 at 05:21:38PM +0200, Miklos Szeredi wrote: > On Fri, May 22, 2015 at 01:59:32PM -0500, Seth Forshee wrote: > > 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. > > Attaching updated patch against fuse.git for-next. Check namespace in both > device read and write. Check them at the start (doesn't matter if requests are > stuck in the queue, if server isn't playing by the rules, then all is lost > anyway). > > One thing: we return error if current tgid isn't valid in server's namespace. > That's looks good. However we silently succeed and set in.h.pid to zero if > current pid isn't representable in the server's namespace. That doesn't sound > quite right. > > Again the question is, does it make sense to allow access by tasks whose pid > isn't representable in the server. If not, then they should be rejected instead > of succeeding with an invalid PID, right? All of the fuse filesystems I looked at didn't pay any attention at all to in.h.pid, and I don't see any reason to make them unusable by processes outside the pid namespace. Filesystems which do care about pids can reject requests when in.h.pid is 0 if they wish. Of course it's a different matter if there are existing filesystems which could be broken by in.h.pid == 0. 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
Seth Forshee <seth.forshee@canonical.com> writes: > On Tue, May 26, 2015 at 05:21:38PM +0200, Miklos Szeredi wrote: >> On Fri, May 22, 2015 at 01:59:32PM -0500, Seth Forshee wrote: >> > 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. >> >> Attaching updated patch against fuse.git for-next. Check namespace in both >> device read and write. Check them at the start (doesn't matter if requests are >> stuck in the queue, if server isn't playing by the rules, then all is lost >> anyway). >> >> One thing: we return error if current tgid isn't valid in server's namespace. >> That's looks good. However we silently succeed and set in.h.pid to zero if >> current pid isn't representable in the server's namespace. That doesn't sound >> quite right. >> >> Again the question is, does it make sense to allow access by tasks whose pid >> isn't representable in the server. If not, then they should be rejected instead >> of succeeding with an invalid PID, right? > > All of the fuse filesystems I looked at didn't pay any attention at all > to in.h.pid, and I don't see any reason to make them unusable by > processes outside the pid namespace. Filesystems which do care about > pids can reject requests when in.h.pid is 0 if they wish. Well where we came in at was there is a fuse filesystem paying attention to pids and is having problems running in a container because the pids are not translated. > Of course it's a different matter if there are existing filesystems > which could be broken by in.h.pid == 0. It seems there is at least one filesystem being written that has that limitation. Given the way fuse works it does seem reasonable to deny access outside of a pid namespace that the fuse filesystem is in. Set I believe you implemented or were at least considering limiting the clients to the same user namespace as well. Unfortunately the test Miklos proposed is wrong. It tested for pid namespace identity which fails to account for nested pid namespaces. Instead of saying: + if (task_active_pid_ns(current) != fc->pid_ns) + return -EIO; The code should probably say: if (!pid_nr_ns(fc->pid_ns, task_pid(current))) return -EIO; Or possibly: static bool in_pid_ns(struct pid_namespace *ns, struct pid *pid) { return ns->level <= pid->level && pid->numbers[ns->level].ns == ns; } if (!in_pid_ns(fc->pid_ns, task_pid(current))) return -EIO; We don't have the in_pid_ns function but it would be easy enough to add. 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 Tue, May 26, 2015 at 10:31:40PM -0500, Eric W. Biederman wrote: > Seth Forshee <seth.forshee@canonical.com> writes: > > > On Tue, May 26, 2015 at 05:21:38PM +0200, Miklos Szeredi wrote: > >> On Fri, May 22, 2015 at 01:59:32PM -0500, Seth Forshee wrote: > >> > 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. > >> > >> Attaching updated patch against fuse.git for-next. Check namespace in both > >> device read and write. Check them at the start (doesn't matter if requests are > >> stuck in the queue, if server isn't playing by the rules, then all is lost > >> anyway). > >> > >> One thing: we return error if current tgid isn't valid in server's namespace. > >> That's looks good. However we silently succeed and set in.h.pid to zero if > >> current pid isn't representable in the server's namespace. That doesn't sound > >> quite right. > >> > >> Again the question is, does it make sense to allow access by tasks whose pid > >> isn't representable in the server. If not, then they should be rejected instead > >> of succeeding with an invalid PID, right? > > > > All of the fuse filesystems I looked at didn't pay any attention at all > > to in.h.pid, and I don't see any reason to make them unusable by > > processes outside the pid namespace. Filesystems which do care about > > pids can reject requests when in.h.pid is 0 if they wish. > > Well where we came in at was there is a fuse filesystem paying attention > to pids and is having problems running in a container because the pids > are not translated. > > > Of course it's a different matter if there are existing filesystems > > which could be broken by in.h.pid == 0. > > It seems there is at least one filesystem being written that has that > limitation. I haven't seen anything to indicate that this filesystem will be broken by this, just that it's broken by untranslated pids. Presumably it would just reject any requests which aren't representable in its namespace. > Given the way fuse works it does seem reasonable to deny access outside > of a pid namespace that the fuse filesystem is in. Set I believe you > implemented or were at least considering limiting the clients to the > same user namespace as well. With user namespaces there's potential (DoS) security concern. I'm not aware of any such concern with pid namespaces. If it's decided as a matter of policy that we won't allow requests when the pid can't be translated, that's fine. All I'm saying is that I know of no technical reason that it shouldn't be permitted. > Unfortunately the test Miklos proposed is wrong. It tested for pid > namespace identity which fails to account for nested pid namespaces. > > Instead of saying: > + if (task_active_pid_ns(current) != fc->pid_ns) > + return -EIO; > > The code should probably say: > if (!pid_nr_ns(fc->pid_ns, task_pid(current))) > return -EIO; > > Or possibly: > static bool in_pid_ns(struct pid_namespace *ns, struct pid *pid) > { > return ns->level <= pid->level && > pid->numbers[ns->level].ns == ns; > } > > > if (!in_pid_ns(fc->pid_ns, task_pid(current))) > return -EIO; > > We don't have the in_pid_ns function but it would be easy enough to add. The proposed checks are in the server's read/write path on /dev/fuse. I don't really think the server should be allowed to change to another pid namespace at all, otherwise fuse needs to delay translating the pid until the read path so it can be sure which namespace to use for the translation. On the other hand if requests are to be rejected based on the pid namespace then it definitely needs to be more like what you've shown here (the patch Miklos posted is not currently doing this). I'm pretty sure that lxcfs [1] is mounted outside of containers for use within them. Seth [1] https://github.com/lxc/lxcfs -- 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 Wed, May 27, 2015 at 2:55 PM, Seth Forshee <seth.forshee@canonical.com> wrote: > I haven't seen anything to indicate that this filesystem will be broken > by this, just that it's broken by untranslated pids. Presumably it would > just reject any requests which aren't representable in its namespace. Without failing the operation there never will be any indication that a filesystem is broken. So I guess the safe way would be - deny access for untranslated pids (uids, gids, etc). - if this becomes an issue (possibly a perfomance issue), then add a flag to disable pids (and/or uids, gids) completely. Thanks, Miklos -- 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
--- 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"); @@ -124,11 +125,11 @@ static void __fuse_put_request(struct fu atomic_dec(&req->count); } -static void fuse_req_init_context(struct fuse_req *req) +static void fuse_req_init_context(struct fuse_conn *fc, struct fuse_req *req) { req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid()); req->in.h.gid = from_kgid_munged(&init_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) @@ -181,7 +182,7 @@ static struct fuse_req *__fuse_get_req(s goto out; } - fuse_req_init_context(req); + fuse_req_init_context(fc, req); __set_bit(FR_WAITING, &req->flags); if (for_background) __set_bit(FR_BACKGROUND, &req->flags); @@ -274,7 +275,7 @@ struct fuse_req *fuse_get_req_nofail_nop if (!req) req = get_reserved_req(fc, file); - fuse_req_init_context(req); + fuse_req_init_context(fc, req); __set_bit(FR_WAITING, &req->flags); __clear_bit(FR_BACKGROUND, &req->flags); return req; @@ -1243,6 +1244,9 @@ static ssize_t fuse_dev_do_read(struct f struct fuse_in *in; unsigned reqsize; + if (task_active_pid_ns(current) != fc->pid_ns) + return -EIO; + restart: spin_lock(&fiq->waitq.lock); err = -EAGAIN; @@ -1872,6 +1876,9 @@ static ssize_t fuse_dev_do_write(struct struct fuse_req *req; struct fuse_out_header oh; + if (task_active_pid_ns(current) != fc->pid_ns) + return -EIO; + if (nbytes < sizeof(struct fuse_out_header)) return -EINVAL; --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -2061,7 +2061,8 @@ static int fuse_direct_mmap(struct file 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 +2077,14 @@ static int convert_fuse_file_lock(const fl->fl_start = ffl->start; fl->fl_end = ffl->end; - fl->fl_pid = ffl->pid; + + /* + * Convert pid into the caller'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 +2133,7 @@ static int fuse_getlk(struct file *file, 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 +2145,8 @@ static int fuse_setlk(struct file *file, 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 +2158,10 @@ static int fuse_setlk(struct file *file, 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 */ --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -22,6 +22,7 @@ #include <linux/rbtree.h> #include <linux/poll.h> #include <linux/workqueue.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 @@ -456,6 +457,9 @@ struct fuse_conn { /** The group id for this mount */ kgid_t group_id; + /** The pid namespace for this mount */ + struct pid_namespace *pid_ns; + /** The fuse mount flags for this mount */ unsigned flags; --- 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"); @@ -609,6 +610,7 @@ void fuse_conn_init(struct fuse_conn *fc fc->connected = 1; fc->attr_version = 1; get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); + fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); } EXPORT_SYMBOL_GPL(fuse_conn_init); @@ -617,6 +619,7 @@ void fuse_conn_put(struct fuse_conn *fc) if (atomic_dec_and_test(&fc->count)) { if (fc->destroy_req) fuse_request_free(fc->destroy_req); + put_pid_ns(fc->pid_ns); fc->release(fc); } }