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freebsd/sys/fs/coda/coda_venus.c
Robert Watson be80264279 Properly bounds check ioctl/pioctl data arguments for Coda:
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
2010-08-07 08:08:14 +00:00

706 lines
18 KiB
C

/*-
* Coda: an Experimental Distributed File System
* Release 3.1
*
* Copyright (c) 1987-1998 Carnegie Mellon University
* All Rights Reserved
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation, and
* that credit is given to Carnegie Mellon University in all documents
* and publicity pertaining to direct or indirect use of this code or its
* derivatives.
*
* CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
* SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
* FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
* DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
* RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
* ANY DERIVATIVE WORK.
*
* Carnegie Mellon encourages users of this software to return any
* improvements or extensions that they make, and to grant Carnegie
* Mellon the rights to redistribute these changes without encumbrance.
*
* @(#) src/sys/cfs/coda_venus.c,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sx.h>
#include <fs/coda/coda.h>
#include <fs/coda/cnode.h>
#include <fs/coda/coda_venus.h>
#include <fs/coda/coda_pioctl.h>
#define DECL_NO_IN(name) \
struct coda_in_hdr *inp; \
struct name ## _out *outp; \
int name ## _size = sizeof (struct coda_in_hdr); \
int Isize = sizeof (struct coda_in_hdr); \
int Osize = sizeof (struct name ## _out); \
int error
#define DECL(name) \
struct name ## _in *inp; \
struct name ## _out *outp; \
int name ## _size = sizeof (struct name ## _in); \
int Isize = sizeof (struct name ## _in); \
int Osize = sizeof (struct name ## _out); \
int error
#define DECL_NO_OUT(name) \
struct name ## _in *inp; \
struct coda_out_hdr *outp; \
int name ## _size = sizeof (struct name ## _in); \
int Isize = sizeof (struct name ## _in); \
int Osize = sizeof (struct coda_out_hdr); \
int error
#define ALLOC_NO_IN(name) \
if (Osize > name ## _size) \
name ## _size = Osize; \
CODA_ALLOC(inp, struct coda_in_hdr *, name ## _size); \
outp = (struct name ## _out *) inp
#define ALLOC(name) \
if (Osize > name ## _size) \
name ## _size = Osize; \
CODA_ALLOC(inp, struct name ## _in *, name ## _size); \
outp = (struct name ## _out *) inp
#define ALLOC_NO_OUT(name) \
if (Osize > name ## _size) \
name ## _size = Osize; \
CODA_ALLOC(inp, struct name ## _in *, name ## _size); \
outp = (struct coda_out_hdr *) inp
#define STRCPY(struc, name, len) \
bcopy(name, (char *)inp + (int)inp->struc, len); \
((char*)inp + (int)inp->struc)[len++] = 0; \
Isize += len
#ifdef CODA_COMPAT_5
#define INIT_IN(in, op, ident, p) do { \
(in)->opcode = (op); \
sx_slock(&proctree_lock); \
(in)->pid = p ? p->p_pid : -1; \
(in)->pgid = p ? p->p_pgid : -1; \
(in)->sid = (p && p->p_session && p->p_session->s_leader) ? \
(p->p_session->s_leader->p_pid) : -1; \
sx_sunlock(&proctree_lock); \
if (ident != NOCRED) { \
(in)->cred.cr_uid = ident->cr_uid; \
(in)->cred.cr_groupid = ident->cr_gid; \
} else { \
bzero(&((in)->cred),sizeof(struct coda_cred)); \
(in)->cred.cr_uid = -1; \
(in)->cred.cr_groupid = -1; \
} \
} while (0)
#else
#define INIT_IN(in, op, ident, p) do { \
(in)->opcode = (op); \
(in)->pid = p ? p->p_pid : -1; \
(in)->pgid = p ? p->p_pgid : -1; \
if (ident != NOCRED) \
(in)->uid = ident->cr_uid; \
else \
(in)->uid = -1; \
} while (0)
#endif
#define CNV_OFLAG(to, from) do { \
to = 0; \
if (from & FREAD) to |= C_O_READ; \
if (from & FWRITE) to |= C_O_WRITE; \
if (from & O_TRUNC) to |= C_O_TRUNC; \
if (from & O_EXCL) to |= C_O_EXCL; \
if (from & O_CREAT) to |= C_O_CREAT; \
} while (0)
#define CNV_VV2V_ATTR(top, fromp) do { \
(top)->va_type = (fromp)->va_type; \
(top)->va_mode = (fromp)->va_mode; \
(top)->va_nlink = (fromp)->va_nlink; \
(top)->va_uid = (fromp)->va_uid; \
(top)->va_gid = (fromp)->va_gid; \
(top)->va_fsid = VNOVAL; \
(top)->va_fileid = (fromp)->va_fileid; \
(top)->va_size = (fromp)->va_size; \
(top)->va_blocksize = (fromp)->va_blocksize; \
(top)->va_atime = (fromp)->va_atime; \
(top)->va_mtime = (fromp)->va_mtime; \
(top)->va_ctime = (fromp)->va_ctime; \
(top)->va_gen = (fromp)->va_gen; \
(top)->va_flags = (fromp)->va_flags; \
(top)->va_rdev = (fromp)->va_rdev; \
(top)->va_bytes = (fromp)->va_bytes; \
(top)->va_filerev = (fromp)->va_filerev; \
(top)->va_vaflags = VNOVAL; \
(top)->va_spare = VNOVAL; \
} while (0)
#define CNV_V2VV_ATTR(top, fromp) do { \
(top)->va_type = (fromp)->va_type; \
(top)->va_mode = (fromp)->va_mode; \
(top)->va_nlink = (fromp)->va_nlink; \
(top)->va_uid = (fromp)->va_uid; \
(top)->va_gid = (fromp)->va_gid; \
(top)->va_fileid = (fromp)->va_fileid; \
(top)->va_size = (fromp)->va_size; \
(top)->va_blocksize = (fromp)->va_blocksize; \
(top)->va_atime = (fromp)->va_atime; \
(top)->va_mtime = (fromp)->va_mtime; \
(top)->va_ctime = (fromp)->va_ctime; \
(top)->va_gen = (fromp)->va_gen; \
(top)->va_flags = (fromp)->va_flags; \
(top)->va_rdev = (fromp)->va_rdev; \
(top)->va_bytes = (fromp)->va_bytes; \
(top)->va_filerev = (fromp)->va_filerev; \
} while (0)
int coda_kernel_version = CODA_KERNEL_VERSION;
int
venus_root(void *mdp, struct ucred *cred, struct proc *p,
/*out*/ struct CodaFid *VFid)
{
DECL_NO_IN(coda_root); /* sets Isize & Osize */
ALLOC_NO_IN(coda_root); /* sets inp & outp */
/* send the open to venus. */
INIT_IN(inp, CODA_ROOT, cred, p);
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error)
*VFid = outp->Fid;
CODA_FREE(inp, coda_root_size);
return (error);
}
int
venus_open(void *mdp, struct CodaFid *fid, int flag, struct ucred *cred,
struct proc *p, /*out*/ struct vnode **vp)
{
int cflag;
DECL(coda_open_by_fd); /* sets Isize & Osize */
ALLOC(coda_open_by_fd); /* sets inp & outp */
/* send the open to venus. */
INIT_IN(&inp->ih, CODA_OPEN_BY_FD, cred, p);
inp->Fid = *fid;
CNV_OFLAG(cflag, flag);
inp->flags = cflag;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
*vp = error ? NULL : outp->vp;
CODA_FREE(inp, coda_open_by_fd_size);
return (error);
}
int
venus_close(void *mdp, struct CodaFid *fid, int flag, struct ucred *cred,
struct proc *p)
{
int cflag;
DECL_NO_OUT(coda_close); /* sets Isize & Osize */
ALLOC_NO_OUT(coda_close); /* sets inp & outp */
INIT_IN(&inp->ih, CODA_CLOSE, cred, p);
inp->Fid = *fid;
CNV_OFLAG(cflag, flag);
inp->flags = cflag;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_close_size);
return (error);
}
/*
* These two calls will not exist!!! The container file is read/written
* directly.
*/
void
venus_read(void)
{
}
void
venus_write(void)
{
}
/*
* This is a bit sad too. the ioctl's are for the control file, not for
* normal files.
*/
int
venus_ioctl(void *mdp, struct CodaFid *fid, int com, int flag, caddr_t data,
struct ucred *cred, struct proc *p)
{
DECL(coda_ioctl); /* sets Isize & Osize */
struct PioctlData *iap = (struct PioctlData *)data;
int tmp;
coda_ioctl_size = VC_MAXMSGSIZE;
ALLOC(coda_ioctl); /* sets inp & outp */
INIT_IN(&inp->ih, CODA_IOCTL, cred, p);
inp->Fid = *fid;
/*
* Command was mutated by increasing its size field to reflect the
* path and follow args. we need to subtract that out before sending
* the command to venus.
*/
inp->cmd = (com & ~(IOCPARM_MASK << 16));
tmp = ((com >> 16) & IOCPARM_MASK) - sizeof (char *) - sizeof (int);
inp->cmd |= (tmp & IOCPARM_MASK) << 16;
if (iap->vi.in_size > VC_MAXMSGSIZE ||
iap->vi.out_size > VC_MAXMSGSIZE) {
CODA_FREE(inp, coda_ioctl_size);
return (EINVAL);
}
inp->rwflag = flag;
inp->len = iap->vi.in_size;
inp->data = (char *)(sizeof (struct coda_ioctl_in));
error = copyin(iap->vi.in, (char*)inp + (long)inp->data,
iap->vi.in_size);
if (error) {
CODA_FREE(inp, coda_ioctl_size);
return (error);
}
Osize = VC_MAXMSGSIZE;
error = coda_call(mdp, Isize + iap->vi.in_size, &Osize, (char *)inp);
/*
* Copy out the out buffer.
*/
if (!error) {
if (outp->len > iap->vi.out_size)
error = EINVAL;
else
error = copyout((char *)outp + (long)outp->data,
iap->vi.out, iap->vi.out_size);
}
CODA_FREE(inp, coda_ioctl_size);
return (error);
}
int
venus_getattr(void *mdp, struct CodaFid *fid, struct ucred *cred,
struct vattr *vap)
{
struct proc *p;
DECL(coda_getattr); /* sets Isize & Osize */
ALLOC(coda_getattr); /* sets inp & outp */
/*
* Send the open to venus.
*/
p = curthread->td_proc;
INIT_IN(&inp->ih, CODA_GETATTR, cred, p);
inp->Fid = *fid;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error)
CNV_VV2V_ATTR(vap, &outp->attr);
CODA_FREE(inp, coda_getattr_size);
return (error);
}
int
venus_setattr(void *mdp, struct CodaFid *fid, struct vattr *vap,
struct ucred *cred)
{
struct proc *p;
DECL_NO_OUT(coda_setattr); /* sets Isize & Osize */
ALLOC_NO_OUT(coda_setattr); /* sets inp & outp */
/*
* Send the open to venus.
*/
p = curthread->td_proc;
INIT_IN(&inp->ih, CODA_SETATTR, cred, p);
inp->Fid = *fid;
CNV_V2VV_ATTR(&inp->attr, vap);
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_setattr_size);
return (error);
}
int
venus_access(void *mdp, struct CodaFid *fid, accmode_t accmode,
struct ucred *cred, struct proc *p)
{
DECL_NO_OUT(coda_access); /* sets Isize & Osize */
ALLOC_NO_OUT(coda_access); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_ACCESS, cred, p);
inp->Fid = *fid;
/*
* NOTE: FreeBSD and Venus internals use the "data" in the low 3
* bits. Hence, the conversion.
*
* XXX: We cast accmode_t variable into an int.
*/
inp->flags = (int)accmode>>6;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_access_size);
return (error);
}
int
venus_readlink(void *mdp, struct CodaFid *fid, struct ucred *cred,
struct proc *p, /*out*/ char **str, int *len)
{
DECL(coda_readlink); /* sets Isize & Osize */
coda_readlink_size += CODA_MAXPATHLEN;
ALLOC(coda_readlink); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_READLINK, cred, p);
inp->Fid = *fid;
Osize += CODA_MAXPATHLEN;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
CODA_ALLOC(*str, char *, outp->count);
*len = outp->count;
bcopy((char *)outp + (long)outp->data, *str, *len);
}
CODA_FREE(inp, coda_readlink_size);
return (error);
}
int
venus_fsync(void *mdp, struct CodaFid *fid, struct proc *p)
{
DECL_NO_OUT(coda_fsync); /* sets Isize & Osize */
ALLOC_NO_OUT(coda_fsync); /* sets inp & outp */
/*
* Send the open to venus.
*
* XXX: should be cached mount cred.
*/
INIT_IN(&inp->ih, CODA_FSYNC, NOCRED, p);
inp->Fid = *fid;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_fsync_size);
return (error);
}
int
venus_lookup(void *mdp, struct CodaFid *fid, const char *nm, int len,
struct ucred *cred, struct proc *p, /*out*/ struct CodaFid *VFid,
int *vtype)
{
DECL(coda_lookup); /* sets Isize & Osize */
coda_lookup_size += len + 1;
ALLOC(coda_lookup); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_LOOKUP, cred, p);
inp->Fid = *fid;
/*
* NOTE: Between version 1 and version 2 we have added an extra flag
* field to this structure. But because the string was at the end
* and because of the wierd way we represent strings by having the
* slot point to where the string characters are in the "heap", we
* can just slip the flag parameter in after the string slot pointer
* and veni that don't know better won't see this new flag field ...
* Otherwise we'd need two different venus_lookup functions.
*/
inp->name = Isize;
inp->flags = CLU_CASE_SENSITIVE; /* doesn't really matter for BSD */
STRCPY(name, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
*VFid = outp->Fid;
*vtype = outp->vtype;
}
CODA_FREE(inp, coda_lookup_size);
return (error);
}
int
venus_create(void *mdp, struct CodaFid *fid, const char *nm, int len,
int exclusive, int mode, struct vattr *va, struct ucred *cred,
struct proc *p, /*out*/ struct CodaFid *VFid, struct vattr *attr)
{
DECL(coda_create); /* sets Isize & Osize */
coda_create_size += len + 1;
ALLOC(coda_create); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_CREATE, cred, p);
inp->Fid = *fid;
inp->excl = exclusive ? C_O_EXCL : 0;
inp->mode = mode;
CNV_V2VV_ATTR(&inp->attr, va);
inp->name = Isize;
STRCPY(name, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
*VFid = outp->Fid;
CNV_VV2V_ATTR(attr, &outp->attr);
}
CODA_FREE(inp, coda_create_size);
return (error);
}
int
venus_remove(void *mdp, struct CodaFid *fid, const char *nm, int len,
struct ucred *cred, struct proc *p)
{
DECL_NO_OUT(coda_remove); /* sets Isize & Osize */
coda_remove_size += len + 1;
ALLOC_NO_OUT(coda_remove); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_REMOVE, cred, p);
inp->Fid = *fid;
inp->name = Isize;
STRCPY(name, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_remove_size);
return (error);
}
int
venus_link(void *mdp, struct CodaFid *fid, struct CodaFid *tfid,
const char *nm, int len, struct ucred *cred, struct proc *p)
{
DECL_NO_OUT(coda_link); /* sets Isize & Osize */
coda_link_size += len + 1;
ALLOC_NO_OUT(coda_link); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_LINK, cred, p);
inp->sourceFid = *fid;
inp->destFid = *tfid;
inp->tname = Isize;
STRCPY(tname, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_link_size);
return (error);
}
int
venus_rename(void *mdp, struct CodaFid *fid, struct CodaFid *tfid,
const char *nm, int len, const char *tnm, int tlen, struct ucred *cred,
struct proc *p)
{
DECL_NO_OUT(coda_rename); /* sets Isize & Osize */
coda_rename_size += len + 1 + tlen + 1;
ALLOC_NO_OUT(coda_rename); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_RENAME, cred, p);
inp->sourceFid = *fid;
inp->destFid = *tfid;
inp->srcname = Isize;
STRCPY(srcname, nm, len); /* increments Isize */
inp->destname = Isize;
STRCPY(destname, tnm, tlen); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_rename_size);
return (error);
}
int
venus_mkdir(void *mdp, struct CodaFid *fid, const char *nm, int len,
struct vattr *va, struct ucred *cred, struct proc *p,
/*out*/ struct CodaFid *VFid, struct vattr *ova)
{
DECL(coda_mkdir); /* sets Isize & Osize */
coda_mkdir_size += len + 1;
ALLOC(coda_mkdir); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_MKDIR, cred, p);
inp->Fid = *fid;
CNV_V2VV_ATTR(&inp->attr, va);
inp->name = Isize;
STRCPY(name, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
*VFid = outp->Fid;
CNV_VV2V_ATTR(ova, &outp->attr);
}
CODA_FREE(inp, coda_mkdir_size);
return (error);
}
int
venus_rmdir(void *mdp, struct CodaFid *fid, const char *nm, int len,
struct ucred *cred, struct proc *p)
{
DECL_NO_OUT(coda_rmdir); /* sets Isize & Osize */
coda_rmdir_size += len + 1;
ALLOC_NO_OUT(coda_rmdir); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_RMDIR, cred, p);
inp->Fid = *fid;
inp->name = Isize;
STRCPY(name, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_rmdir_size);
return (error);
}
int
venus_symlink(void *mdp, struct CodaFid *fid, const char *lnm, int llen,
const char *nm, int len, struct vattr *va, struct ucred *cred,
struct proc *p)
{
DECL_NO_OUT(coda_symlink); /* sets Isize & Osize */
coda_symlink_size += llen + 1 + len + 1;
ALLOC_NO_OUT(coda_symlink); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_SYMLINK, cred, p);
inp->Fid = *fid;
CNV_V2VV_ATTR(&inp->attr, va);
inp->srcname = Isize;
STRCPY(srcname, lnm, llen); /* increments Isize */
inp->tname = Isize;
STRCPY(tname, nm, len); /* increments Isize */
error = coda_call(mdp, Isize, &Osize, (char *)inp);
CODA_FREE(inp, coda_symlink_size);
return (error);
}
/*
* XXX: Unused.
*/
int
venus_readdir(void *mdp, struct CodaFid *fid, int count, int offset,
struct ucred *cred, struct proc *p, /*out*/ char *buffer, int *len)
{
DECL(coda_readdir); /* sets Isize & Osize */
coda_readdir_size = VC_MAXMSGSIZE;
ALLOC(coda_readdir); /* sets inp & outp */
/*
* Send the open to venus.
*/
INIT_IN(&inp->ih, CODA_READDIR, cred, p);
inp->Fid = *fid;
inp->count = count;
inp->offset = offset;
Osize = VC_MAXMSGSIZE;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
bcopy((char *)outp + (long)outp->data, buffer, outp->size);
*len = outp->size;
}
CODA_FREE(inp, coda_readdir_size);
return (error);
}
int
venus_fhtovp(void *mdp, struct CodaFid *fid, struct ucred *cred,
struct proc *p, /*out*/ struct CodaFid *VFid, int *vtype)
{
DECL(coda_vget); /* sets Isize & Osize */
ALLOC(coda_vget); /* sets inp & outp */
/*
* Send the open to Venus.
*/
INIT_IN(&inp->ih, CODA_VGET, cred, p);
inp->Fid = *fid;
error = coda_call(mdp, Isize, &Osize, (char *)inp);
if (!error) {
*VFid = outp->Fid;
*vtype = outp->vtype;
}
CODA_FREE(inp, coda_vget_size);
return (error);
}