From 0b6e9ea041e6c932f5b3a86fae2d60cbcfad4dd2 Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Wed, 2 Jul 2014 16:29:19 -0500 Subject: fuse: Add support for pid namespaces When the userspace process servicing fuse requests is running in a pid namespace then pids passed via the fuse fd are not being translated into that process' namespace. Translation is necessary for the pid to be useful to that process. Since no use case currently exists for changing namespaces all translations can be done relative to the pid namespace in use when fuse_conn_init() is called. For fuse this translates to mount time, and for cuse this is when /dev/cuse is opened. IO for this connection from another namespace will return errors. Requests from processes whose pid cannot be translated into the target namespace will have a value of 0 for in.h.pid. File locking changes based on previous work done by Eric Biederman. Signed-off-by: Seth Forshee Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'fs/fuse/dev.c') diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 5e815072be1b..f95682115bc2 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -20,6 +20,7 @@ #include #include #include +#include MODULE_ALIAS_MISCDEV(FUSE_MINOR); MODULE_ALIAS("devname:fuse"); @@ -111,11 +112,11 @@ static void __fuse_put_request(struct fuse_req *req) refcount_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) @@ -162,7 +163,7 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages, 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); @@ -255,7 +256,7 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, 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; @@ -1222,6 +1223,9 @@ static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, 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; @@ -1820,6 +1824,9 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud, 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; -- cgit v1.2.3