freebsd-dev/sys/geom/eli/g_eli_privacy.c
Pawel Jakub Dawidek 5ee9ea19fe After crypto_dispatch() bio might be already delivered and destroyed,
so we cannot access it anymore. Setting an error later lead to memory
corruption.

Assert that crypto_dispatch() was successful. It can fail only if we pass a
bogus crypto request, which is a bug in the program, not a runtime condition.

PR:		199705
Submitted by:	luke.tw
Reviewed by:	emaste
MFC after:	3 days
2015-08-06 17:13:34 +00:00

315 lines
9.0 KiB
C

/*-
* Copyright (c) 2005-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/bio.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/kthread.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/vnode.h>
#include <vm/uma.h>
#include <geom/geom.h>
#include <geom/eli/g_eli.h>
#include <geom/eli/pkcs5v2.h>
/*
* Code paths:
* BIO_READ:
* g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
* BIO_WRITE:
* g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
*/
MALLOC_DECLARE(M_ELI);
/*
* The function is called after we read and decrypt data.
*
* g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> G_ELI_CRYPTO_READ_DONE -> g_io_deliver
*/
static int
g_eli_crypto_read_done(struct cryptop *crp)
{
struct g_eli_softc *sc;
struct bio *bp;
if (crp->crp_etype == EAGAIN) {
if (g_eli_crypto_rerun(crp) == 0)
return (0);
}
bp = (struct bio *)crp->crp_opaque;
bp->bio_inbed++;
if (crp->crp_etype == 0) {
G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
bp->bio_inbed, bp->bio_children);
bp->bio_completed += crp->crp_olen;
} else {
G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
bp->bio_inbed, bp->bio_children, crp->crp_etype);
if (bp->bio_error == 0)
bp->bio_error = crp->crp_etype;
}
sc = bp->bio_to->geom->softc;
g_eli_key_drop(sc, crp->crp_desc->crd_key);
/*
* Do we have all sectors already?
*/
if (bp->bio_inbed < bp->bio_children)
return (0);
free(bp->bio_driver2, M_ELI);
bp->bio_driver2 = NULL;
if (bp->bio_error != 0) {
G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
bp->bio_error);
bp->bio_completed = 0;
}
/*
* Read is finished, send it up.
*/
g_io_deliver(bp, bp->bio_error);
atomic_subtract_int(&sc->sc_inflight, 1);
return (0);
}
/*
* The function is called after data encryption.
*
* g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
*/
static int
g_eli_crypto_write_done(struct cryptop *crp)
{
struct g_eli_softc *sc;
struct g_geom *gp;
struct g_consumer *cp;
struct bio *bp, *cbp;
if (crp->crp_etype == EAGAIN) {
if (g_eli_crypto_rerun(crp) == 0)
return (0);
}
bp = (struct bio *)crp->crp_opaque;
bp->bio_inbed++;
if (crp->crp_etype == 0) {
G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
bp->bio_inbed, bp->bio_children);
} else {
G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
bp->bio_inbed, bp->bio_children, crp->crp_etype);
if (bp->bio_error == 0)
bp->bio_error = crp->crp_etype;
}
gp = bp->bio_to->geom;
sc = gp->softc;
g_eli_key_drop(sc, crp->crp_desc->crd_key);
/*
* All sectors are already encrypted?
*/
if (bp->bio_inbed < bp->bio_children)
return (0);
bp->bio_inbed = 0;
bp->bio_children = 1;
cbp = bp->bio_driver1;
bp->bio_driver1 = NULL;
if (bp->bio_error != 0) {
G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
bp->bio_error);
free(bp->bio_driver2, M_ELI);
bp->bio_driver2 = NULL;
g_destroy_bio(cbp);
g_io_deliver(bp, bp->bio_error);
atomic_subtract_int(&sc->sc_inflight, 1);
return (0);
}
cbp->bio_data = bp->bio_driver2;
cbp->bio_done = g_eli_write_done;
cp = LIST_FIRST(&gp->consumer);
cbp->bio_to = cp->provider;
G_ELI_LOGREQ(2, cbp, "Sending request.");
/*
* Send encrypted data to the provider.
*/
g_io_request(cbp, cp);
return (0);
}
/*
* The function is called to read encrypted data.
*
* g_eli_start -> G_ELI_CRYPTO_READ -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
*/
void
g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
{
struct g_consumer *cp;
struct bio *cbp;
if (!fromworker) {
/*
* We are not called from the worker thread, so check if
* device is suspended.
*/
mtx_lock(&sc->sc_queue_mtx);
if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
/*
* If device is suspended, we place the request onto
* the queue, so it can be handled after resume.
*/
G_ELI_DEBUG(0, "device suspended, move onto queue");
bioq_insert_tail(&sc->sc_queue, bp);
mtx_unlock(&sc->sc_queue_mtx);
wakeup(sc);
return;
}
atomic_add_int(&sc->sc_inflight, 1);
mtx_unlock(&sc->sc_queue_mtx);
}
bp->bio_pflags = 0;
bp->bio_driver2 = NULL;
cbp = bp->bio_driver1;
cbp->bio_done = g_eli_read_done;
cp = LIST_FIRST(&sc->sc_geom->consumer);
cbp->bio_to = cp->provider;
G_ELI_LOGREQ(2, cbp, "Sending request.");
/*
* Read encrypted data from provider.
*/
g_io_request(cbp, cp);
}
/*
* This is the main function responsible for cryptography (ie. communication
* with crypto(9) subsystem).
*
* BIO_READ:
* g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> G_ELI_CRYPTO_RUN -> g_eli_crypto_read_done -> g_io_deliver
* BIO_WRITE:
* g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
*/
void
g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
{
struct g_eli_softc *sc;
struct cryptop *crp;
struct cryptodesc *crd;
u_int i, nsec, secsize;
off_t dstoff;
size_t size;
u_char *p, *data;
int error;
G_ELI_LOGREQ(3, bp, "%s", __func__);
bp->bio_pflags = wr->w_number;
sc = wr->w_softc;
secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
nsec = bp->bio_length / secsize;
/*
* Calculate how much memory do we need.
* We need separate crypto operation for every single sector.
* It is much faster to calculate total amount of needed memory here and
* do the allocation once instead of allocating memory in pieces (many,
* many pieces).
*/
size = sizeof(*crp) * nsec;
size += sizeof(*crd) * nsec;
/*
* If we write the data we cannot destroy current bio_data content,
* so we need to allocate more memory for encrypted data.
*/
if (bp->bio_cmd == BIO_WRITE)
size += bp->bio_length;
p = malloc(size, M_ELI, M_WAITOK);
bp->bio_inbed = 0;
bp->bio_children = nsec;
bp->bio_driver2 = p;
if (bp->bio_cmd == BIO_READ)
data = bp->bio_data;
else {
data = p;
p += bp->bio_length;
bcopy(bp->bio_data, data, bp->bio_length);
}
for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
crp = (struct cryptop *)p; p += sizeof(*crp);
crd = (struct cryptodesc *)p; p += sizeof(*crd);
crp->crp_sid = wr->w_sid;
crp->crp_ilen = secsize;
crp->crp_olen = secsize;
crp->crp_opaque = (void *)bp;
crp->crp_buf = (void *)data;
data += secsize;
if (bp->bio_cmd == BIO_WRITE)
crp->crp_callback = g_eli_crypto_write_done;
else /* if (bp->bio_cmd == BIO_READ) */
crp->crp_callback = g_eli_crypto_read_done;
crp->crp_flags = CRYPTO_F_CBIFSYNC;
if (g_eli_batch)
crp->crp_flags |= CRYPTO_F_BATCH;
crp->crp_desc = crd;
crd->crd_skip = 0;
crd->crd_len = secsize;
crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0)
crd->crd_flags |= CRD_F_KEY_EXPLICIT;
if (bp->bio_cmd == BIO_WRITE)
crd->crd_flags |= CRD_F_ENCRYPT;
crd->crd_alg = sc->sc_ealgo;
crd->crd_key = g_eli_key_hold(sc, dstoff, secsize);
crd->crd_klen = sc->sc_ekeylen;
if (sc->sc_ealgo == CRYPTO_AES_XTS)
crd->crd_klen <<= 1;
g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
sizeof(crd->crd_iv));
crd->crd_next = NULL;
crp->crp_etype = 0;
error = crypto_dispatch(crp);
KASSERT(error == 0, ("crypto_dispatch() failed (error=%d)",
error));
}
}