1. Use unsigned rather than signed lengths
2. Bound messages to/from Venus to VC_MAXMSGSIZE
3. Bound messages to/from general user processes to VC_MAXDATASIZE
4. Update comment regarding data limits for pioctl
Without (1) and (3), it may be possible for unprivileged user processes to
read sensitive portions of kernel memory. This issue is only present if
the Coda kernel module is loaded and venus (the userspace Coda daemon) is
running and has /coda mounted.
As Coda is considered experimental and production use is warned against in
the coda(4) man page, and because Coda must be explicitly configured for a
configuration to be vulnerable, we won't be issuing a security advisory.
However, if you are using Coda, then you are advised to apply these fixes.
Reported by: Dan J. Rosenberg <drosenberg at vsecurity.com>
Obtained from: NetBSD (Christos Zoulas)
Security: Kernel memory disclosure; no advisory as feature experimental
MFC after: 3 days
coda.h:
- CodaFid typdef -> struct CodaFid throughout.
- Use unsigned int instead of unsigned long for venus_dirent and other
cosmetic fixes.
- Introduce cuid_t and cgid_t and use instead of uid_t and gid_t in RPCs.
- Synchronize comments and macros.
- Use u_int32_t instead of unsigned long for coda_out_hdr.
With these changes, a 64-bit Coda kernel module now works with
coda6_client, whereas previous userspace and kernel versions of RPCs
differed sufficiently to prevent using the file system. This has been
verified only with casual testing, but /coda is now usable for at least
basic operations on amd64.
MFC after: 1 week
we can't open container files by device/inode number pair anymore.
Replace the CODA_OPEN upcall with CODA_OPEN_BY_FD, where venus returns
an open file descriptor for the container file. We can then grab a
reference on the vnode coda_psdev.c:vc_nb_write and use this vnode for
further accesses to the container file.
Submitted by: Jan Harkes <jaharkes@cs.cmu.edu>
Approved by: re (kensmith)
Otherwise a kernel build would break in the coda5 module if the main
kernel conf file enabled CODA_COMPAT_5, too. Redefined symbols are
strictly disallowed by -Werror.
To overcome this issue, introduce a different symbol indicating coda5
build, CODA5_MODULE, and translate it to CODA_COMPAT_5 appropriately
in /sys/coda/coda.h.
MFC after: 3 days
The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
FIDs to be 128-bits wide and adds support for realms.
Add a new CODA_COMPAT_5 option, which requests support for the old
Coda 5.x interface instead of the new one.
Create a new coda5.ko module that supports the 5.x interface, and make
the existing coda.ko module use the new 6.x interface. These modules
cannot both be loaded at the same time.
Obtained from: Jan Harkes & the coda-6.0.2 distribution,
NetBSD (drochner) (CODA_COMPAT_5 option).
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.
udev_t in the kernel but still called dev_t in userland.
Provide functions to manipulate both types:
major() umajor()
minor() uminor()
makedev() umakedev()
dev2udev() udev2dev()
For now they're functions, they will become in-line functions
after one of the next two steps in this process.
Return major/minor/makedev to macro-hood for userland.
Register a name in cdevsw[] for the "filedescriptor" driver.
In the kernel the udev_t appears in places where we have the
major/minor number combination, (ie: a potential device: we
may not have the driver nor the device), like in inodes, vattr,
cdevsw registration and so on, whereas the dev_t appears where
we carry around a reference to a actual device.
In the future the cdevsw and the aliased-from vnode will be hung
directly from the dev_t, along with up to two softc pointers for
the device driver and a few houskeeping bits. This will essentially
replace the current "alias" check code (same buck, bigger bang).
A little stunt has been provided to try to catch places where the
wrong type is being used (dev_t vs udev_t), if you see something
not working, #undef DEVT_FASCIST in kern/kern_conf.c and see if
it makes a difference. If it does, please try to track it down
(many hands make light work) or at least try to reproduce it
as simply as possible, and describe how to do that.
Without DEVT_FASCIST I belive this patch is a no-op.
Stylistic/posixoid comments about the userland view of the <sys/*.h>
files welcome now, from userland they now contain the end result.
Next planned step: make all dev_t's refer to the same devsw[] which
means convert BLK's to CHR's at the perimeter of the vnodes and
other places where they enter the game (bootdev, mknod, sysctl).
