Miklos Szeredi 5d6d3a301c fuse: allow server to run in different pid_ns ... Commit 0b6e9ea041 ("fuse: Add support for pid namespaces") broke Sandstorm.io development tools, which have been sending FUSE file descriptors across PID namespace boundaries since early 2014. The above patch added a check that prevented I/O on the fuse device file descriptor if the pid namespace of the reader/writer was different from the pid namespace of the mounter. With this change passing the device file descriptor to a different pid namespace simply doesn't work. The check was added because pids are transferred to/from the fuse userspace server in the namespace registered at mount time. To fix this regression, remove the checks and do the following: 1) the pid in the request header (the pid of the task that initiated the filesystem operation) is translated to the reader's pid namespace. If a mapping doesn't exist for this pid, then a zero pid is used. Note: even if a mapping would exist between the initiator task's pid namespace and the reader's pid namespace the pid will be zero if either mapping from initator's to mounter's namespace or mapping from mounter's to reader's namespace doesn't exist. 2) The lk.pid value in setlk/setlkw requests and getlk reply is left alone. Userspace should not interpret this value anyway. Also allow the setlk/setlkw operations if the pid of the task cannot be represented in the mounter's namespace (pid being zero in that case). Reported-by: Kenton Varda <kenton@sandstorm.io> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 0b6e9ea041 ("fuse: Add support for pid namespaces") Cc: <stable@vger.kernel.org> # v4.12+ Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Seth Forshee <seth.forshee@canonical.com>		2017-09-12 16:57:53 +02:00
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acl.c	fuse: Add posix ACL support	2016-10-01 07:32:32 +02:00
control.c	fs: constify tree_descr arrays passed to simple_fill_super()	2017-04-26 23:54:06 -04:00
cuse.c	fuse: Add reference counting for fuse_io_priv	2016-03-14 15:02:51 +01:00
dev.c	fuse: allow server to run in different pid_ns	2017-09-12 16:57:53 +02:00
dir.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse	2017-03-03 12:14:13 -08:00
file.c	fuse: allow server to run in different pid_ns	2017-09-12 16:57:53 +02:00
fuse_i.h	fuse: Dont call set_page_dirty_lock() for ITER_BVEC pages for async_dio	2017-08-03 17:55:58 +02:00
inode.c	Merge branch 'for-linus' of git://git.kernel.dk/linux-block	2017-05-20 16:12:30 -07:00
Kconfig	fuse: Add posix ACL support	2016-10-01 07:32:32 +02:00
Makefile	fuse: Use generic xattr ops	2016-10-01 07:32:32 +02:00
xattr.c	fuse: limit xattr returned size	2016-10-03 11:06:05 +02:00