coda: Restrict coda messages to the initial user namespace
Remove the slight chance that uids and gids in coda messages will be
interpreted in the wrong user namespace.
- Only allow processes in the initial user namespace to open the coda
character device to communicate with coda filesystems.
- Explicitly convert the uids in the coda header into the initial user
namespace.
- In coda_vattr_to_attr make kuids and kgids from the initial user
namespace uids and gids in struct coda_vattr that just came from
userspace.
- In coda_iattr_to_vattr convert kuids and kgids into uids and gids
in the intial user namespace and store them in struct coda_vattr for
sending to coda userspace programs.
Nothing needs to be changed with mounts as coda does not support
being mounted in anything other than the initial user namespace.
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/coda/upcall.c b/fs/coda/upcall.c
index 5c6d2cd..3a73197 100644
--- a/fs/coda/upcall.c
+++ b/fs/coda/upcall.c
@@ -52,7 +52,7 @@
inp->ih.opcode = opcode;
inp->ih.pid = task_pid_nr_ns(current, &init_pid_ns);
inp->ih.pgid = task_pgrp_nr_ns(current, &init_pid_ns);
- inp->ih.uid = current_fsuid();
+ inp->ih.uid = from_kuid(&init_user_ns, current_fsuid());
return (void*)inp;
}
@@ -157,7 +157,7 @@
}
int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
- vuid_t uid)
+ kuid_t uid)
{
union inputArgs *inp;
union outputArgs *outp;
@@ -166,7 +166,7 @@
insize = SIZE(release);
UPARG(CODA_CLOSE);
- inp->ih.uid = uid;
+ inp->ih.uid = from_kuid(&init_user_ns, uid);
inp->coda_close.VFid = *fid;
inp->coda_close.flags = flags;
