linux/fs/lockd/xdr4.c
Jeff Layton 7ff84910c6 lockd: set file_lock start and end when decoding nlm4 testargs
Commit 6930bcbfb6 dropped the setting of the file_lock range when
decoding a nlm_lock off the wire. This causes the client side grant
callback to miss matching blocks and reject the lock, only to rerequest
it 30s later.

Add a helper function to set the file_lock range from the start and end
values that the protocol uses, and have the nlm_lock decoder call that to
set up the file_lock args properly.

Fixes: 6930bcbfb6 ("lockd: detect and reject lock arguments that overflow")
Reported-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Amir Goldstein <amir73il@gmail.com>
Cc: stable@vger.kernel.org #6.0
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-03-14 14:00:55 -04:00

350 lines
7.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/lockd/xdr4.c
*
* XDR support for lockd and the lock client.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
* Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/nfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>
#include "svcxdr.h"
static inline s64
loff_t_to_s64(loff_t offset)
{
s64 res;
if (offset > NLM4_OFFSET_MAX)
res = NLM4_OFFSET_MAX;
else if (offset < -NLM4_OFFSET_MAX)
res = -NLM4_OFFSET_MAX;
else
res = offset;
return res;
}
void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len)
{
s64 end = off + len - 1;
fl->fl_start = off;
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = end;
}
/*
* NLM file handles are defined by specification to be a variable-length
* XDR opaque no longer than 1024 bytes. However, this implementation
* limits their length to the size of an NFSv3 file handle.
*/
static bool
svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
{
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > NFS_MAXFHSIZE)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
fh->size = len;
memcpy(fh->data, p, len);
memset(fh->data + len, 0, sizeof(fh->data) - len);
return true;
}
static bool
svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
{
struct file_lock *fl = &lock->fl;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (!svcxdr_decode_fhandle(xdr, &lock->fh))
return false;
if (!svcxdr_decode_owner(xdr, &lock->oh))
return false;
if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
return false;
if (xdr_stream_decode_u64(xdr, &lock->lock_start) < 0)
return false;
if (xdr_stream_decode_u64(xdr, &lock->lock_len) < 0)
return false;
locks_init_lock(fl);
fl->fl_flags = FL_POSIX;
fl->fl_type = F_RDLCK;
nlm4svc_set_file_lock_range(fl, lock->lock_start, lock->lock_len);
return true;
}
static bool
svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
{
const struct file_lock *fl = &lock->fl;
s64 start, len;
/* exclusive */
if (xdr_stream_encode_bool(xdr, fl->fl_type != F_RDLCK) < 0)
return false;
if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
return false;
if (!svcxdr_encode_owner(xdr, &lock->oh))
return false;
start = loff_t_to_s64(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
len = 0;
else
len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
if (xdr_stream_encode_u64(xdr, start) < 0)
return false;
if (xdr_stream_encode_u64(xdr, len) < 0)
return false;
return true;
}
static bool
svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
{
if (!svcxdr_encode_stats(xdr, resp->status))
return false;
switch (resp->status) {
case nlm_lck_denied:
if (!svcxdr_encode_holder(xdr, &resp->lock))
return false;
}
return true;
}
/*
* Decode Call arguments
*/
bool
nlm4svc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
bool
nlm4svc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return true;
}
bool
nlm4svc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
argp->monitor = 1; /* monitor client by default */
return true;
}
bool
nlm4svc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return true;
}
bool
nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
argp->lock.fl.fl_type = F_UNLCK;
return true;
}
bool
nlm4svc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_argp;
if (!svcxdr_decode_cookie(xdr, &resp->cookie))
return false;
if (!svcxdr_decode_stats(xdr, &resp->status))
return false;
return true;
}
bool
nlm4svc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_reboot *argp = rqstp->rq_argp;
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > SM_MAXSTRLEN)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
argp->len = len;
argp->mon = (char *)p;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
if (!p)
return false;
memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
return true;
}
bool
nlm4svc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
struct nlm_lock *lock = &argp->lock;
memset(lock, 0, sizeof(*lock));
locks_init_lock(&lock->fl);
lock->svid = ~(u32)0;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (!svcxdr_decode_fhandle(xdr, &lock->fh))
return false;
if (!svcxdr_decode_owner(xdr, &lock->oh))
return false;
/* XXX: Range checks are missing in the original code */
if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
return false;
return true;
}
bool
nlm4svc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
struct nlm_lock *lock = &argp->lock;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
return true;
}
/*
* Encode Reply results
*/
bool
nlm4svc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
bool
nlm4svc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
return svcxdr_encode_cookie(xdr, &resp->cookie) &&
svcxdr_encode_testrply(xdr, resp);
}
bool
nlm4svc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
return svcxdr_encode_cookie(xdr, &resp->cookie) &&
svcxdr_encode_stats(xdr, resp->status);
}
bool
nlm4svc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
if (!svcxdr_encode_cookie(xdr, &resp->cookie))
return false;
if (!svcxdr_encode_stats(xdr, resp->status))
return false;
/* sequence */
if (xdr_stream_encode_u32(xdr, 0) < 0)
return false;
return true;
}