Revision eecc1e426d681351a6026a7d3e7d225f38955b6c authored by Hugh Dickins on 12 January 2014, 09:25:21 UTC, committed by Linus Torvalds on 12 January 2014, 09:47:15 UTC
We see General Protection Fault on RSI in copy_page_rep: that RSI is what you get from a NULL struct page pointer. RIP: 0010:[<ffffffff81154955>] [<ffffffff81154955>] copy_page_rep+0x5/0x10 RSP: 0000:ffff880136e15c00 EFLAGS: 00010286 RAX: ffff880000000000 RBX: ffff880136e14000 RCX: 0000000000000200 RDX: 6db6db6db6db6db7 RSI: db73880000000000 RDI: ffff880dd0c00000 RBP: ffff880136e15c18 R08: 0000000000000200 R09: 000000000005987c R10: 000000000005987c R11: 0000000000000200 R12: 0000000000000001 R13: ffffea00305aa000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f195752f700(0000) GS:ffff880c7fc20000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000093010000 CR3: 00000001458e1000 CR4: 00000000000027e0 Call Trace: copy_user_huge_page+0x93/0xab do_huge_pmd_wp_page+0x710/0x815 handle_mm_fault+0x15d8/0x1d70 __do_page_fault+0x14d/0x840 do_page_fault+0x2f/0x90 page_fault+0x22/0x30 do_huge_pmd_wp_page() tests is_huge_zero_pmd(orig_pmd) four times: but since shrink_huge_zero_page() can free the huge_zero_page, and we have no hold of our own on it here (except where the fourth test holds page_table_lock and has checked pmd_same), it's possible for it to answer yes the first time, but no to the second or third test. Change all those last three to tests for NULL page. (Note: this is not the same issue as trinity's DEBUG_PAGEALLOC BUG in copy_page_rep with RSI: ffff88009c422000, reported by Sasha Levin in https://lkml.org/lkml/2013/3/29/103. I believe that one is due to the source page being split, and a tail page freed, while copy is in progress; and not a problem without DEBUG_PAGEALLOC, since the pmd_same check will prevent a miscopy from being made visible.) Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org # v3.10 v3.11 v3.12 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 518d00b
aead.c
/*
* AEAD: Authenticated Encryption with Associated Data
*
* This file provides API support for AEAD algorithms.
*
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/internal/aead.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include "internal.h"
static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
unsigned int keylen)
{
struct aead_alg *aead = crypto_aead_alg(tfm);
unsigned long alignmask = crypto_aead_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = aead->setkey(tfm, alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
{
struct aead_alg *aead = crypto_aead_alg(tfm);
unsigned long alignmask = crypto_aead_alignmask(tfm);
if ((unsigned long)key & alignmask)
return setkey_unaligned(tfm, key, keylen);
return aead->setkey(tfm, key, keylen);
}
int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
struct aead_tfm *crt = crypto_aead_crt(tfm);
int err;
if (authsize > crypto_aead_alg(tfm)->maxauthsize)
return -EINVAL;
if (crypto_aead_alg(tfm)->setauthsize) {
err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
if (err)
return err;
}
crypto_aead_crt(crt->base)->authsize = authsize;
crt->authsize = authsize;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
return alg->cra_ctxsize;
}
static int no_givcrypt(struct aead_givcrypt_request *req)
{
return -ENOSYS;
}
static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
struct aead_tfm *crt = &tfm->crt_aead;
if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
alg->setkey : setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
crt->givencrypt = alg->givencrypt ?: no_givcrypt;
crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
crt->base = __crypto_aead_cast(tfm);
crt->ivsize = alg->ivsize;
crt->authsize = alg->maxauthsize;
return 0;
}
#ifdef CONFIG_NET
static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_aead raead;
struct aead_alg *aead = &alg->cra_aead;
strncpy(raead.type, "aead", sizeof(raead.type));
strncpy(raead.geniv, aead->geniv ?: "<built-in>", sizeof(raead.geniv));
raead.blocksize = alg->cra_blocksize;
raead.maxauthsize = aead->maxauthsize;
raead.ivsize = aead->ivsize;
if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
sizeof(struct crypto_report_aead), &raead))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
#else
static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
{
struct aead_alg *aead = &alg->cra_aead;
seq_printf(m, "type : aead\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "ivsize : %u\n", aead->ivsize);
seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
}
const struct crypto_type crypto_aead_type = {
.ctxsize = crypto_aead_ctxsize,
.init = crypto_init_aead_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_aead_show,
#endif
.report = crypto_aead_report,
};
EXPORT_SYMBOL_GPL(crypto_aead_type);
static int aead_null_givencrypt(struct aead_givcrypt_request *req)
{
return crypto_aead_encrypt(&req->areq);
}
static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
{
return crypto_aead_decrypt(&req->areq);
}
static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
struct aead_tfm *crt = &tfm->crt_aead;
if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
if (!alg->ivsize) {
crt->givencrypt = aead_null_givencrypt;
crt->givdecrypt = aead_null_givdecrypt;
}
crt->base = __crypto_aead_cast(tfm);
crt->ivsize = alg->ivsize;
crt->authsize = alg->maxauthsize;
return 0;
}
#ifdef CONFIG_NET
static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_aead raead;
struct aead_alg *aead = &alg->cra_aead;
strncpy(raead.type, "nivaead", sizeof(raead.type));
strncpy(raead.geniv, aead->geniv, sizeof(raead.geniv));
raead.blocksize = alg->cra_blocksize;
raead.maxauthsize = aead->maxauthsize;
raead.ivsize = aead->ivsize;
if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
sizeof(struct crypto_report_aead), &raead))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
#else
static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
{
struct aead_alg *aead = &alg->cra_aead;
seq_printf(m, "type : nivaead\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "ivsize : %u\n", aead->ivsize);
seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
seq_printf(m, "geniv : %s\n", aead->geniv);
}
const struct crypto_type crypto_nivaead_type = {
.ctxsize = crypto_aead_ctxsize,
.init = crypto_init_nivaead_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_nivaead_show,
#endif
.report = crypto_nivaead_report,
};
EXPORT_SYMBOL_GPL(crypto_nivaead_type);
static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
const char *name, u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;
type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);
err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}
struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
struct rtattr **tb, u32 type,
u32 mask)
{
const char *name;
struct crypto_aead_spawn *spawn;
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_alg *alg;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_CAST(algt);
if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
algt->mask)
return ERR_PTR(-EINVAL);
name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(name))
return ERR_CAST(name);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);
spawn = crypto_instance_ctx(inst);
/* Ignore async algorithms if necessary. */
mask |= crypto_requires_sync(algt->type, algt->mask);
crypto_set_aead_spawn(spawn, inst);
err = crypto_grab_nivaead(spawn, name, type, mask);
if (err)
goto err_free_inst;
alg = crypto_aead_spawn_alg(spawn);
err = -EINVAL;
if (!alg->cra_aead.ivsize)
goto err_drop_alg;
/*
* This is only true if we're constructing an algorithm with its
* default IV generator. For the default generator we elide the
* template name and double-check the IV generator.
*/
if (algt->mask & CRYPTO_ALG_GENIV) {
if (strcmp(tmpl->name, alg->cra_aead.geniv))
goto err_drop_alg;
memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
CRYPTO_MAX_ALG_NAME);
} else {
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"%s(%s)", tmpl->name, alg->cra_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_alg;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"%s(%s)", tmpl->name, alg->cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_alg;
}
inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_aead_type;
inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
out:
return inst;
err_drop_alg:
crypto_drop_aead(spawn);
err_free_inst:
kfree(inst);
inst = ERR_PTR(err);
goto out;
}
EXPORT_SYMBOL_GPL(aead_geniv_alloc);
void aead_geniv_free(struct crypto_instance *inst)
{
crypto_drop_aead(crypto_instance_ctx(inst));
kfree(inst);
}
EXPORT_SYMBOL_GPL(aead_geniv_free);
int aead_geniv_init(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_aead *aead;
aead = crypto_spawn_aead(crypto_instance_ctx(inst));
if (IS_ERR(aead))
return PTR_ERR(aead);
tfm->crt_aead.base = aead;
tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
return 0;
}
EXPORT_SYMBOL_GPL(aead_geniv_init);
void aead_geniv_exit(struct crypto_tfm *tfm)
{
crypto_free_aead(tfm->crt_aead.base);
}
EXPORT_SYMBOL_GPL(aead_geniv_exit);
static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
{
struct rtattr *tb[3];
struct {
struct rtattr attr;
struct crypto_attr_type data;
} ptype;
struct {
struct rtattr attr;
struct crypto_attr_alg data;
} palg;
struct crypto_template *tmpl;
struct crypto_instance *inst;
struct crypto_alg *larval;
const char *geniv;
int err;
larval = crypto_larval_lookup(alg->cra_driver_name,
CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
err = PTR_ERR(larval);
if (IS_ERR(larval))
goto out;
err = -EAGAIN;
if (!crypto_is_larval(larval))
goto drop_larval;
ptype.attr.rta_len = sizeof(ptype);
ptype.attr.rta_type = CRYPTOA_TYPE;
ptype.data.type = type | CRYPTO_ALG_GENIV;
/* GENIV tells the template that we're making a default geniv. */
ptype.data.mask = mask | CRYPTO_ALG_GENIV;
tb[0] = &ptype.attr;
palg.attr.rta_len = sizeof(palg);
palg.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
tb[1] = &palg.attr;
tb[2] = NULL;
geniv = alg->cra_aead.geniv;
tmpl = crypto_lookup_template(geniv);
err = -ENOENT;
if (!tmpl)
goto kill_larval;
inst = tmpl->alloc(tb);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto put_tmpl;
if ((err = crypto_register_instance(tmpl, inst))) {
tmpl->free(inst);
goto put_tmpl;
}
/* Redo the lookup to use the instance we just registered. */
err = -EAGAIN;
put_tmpl:
crypto_tmpl_put(tmpl);
kill_larval:
crypto_larval_kill(larval);
drop_larval:
crypto_mod_put(larval);
out:
crypto_mod_put(alg);
return err;
}
struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask)
{
struct crypto_alg *alg;
alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return alg;
if (alg->cra_type == &crypto_aead_type)
return alg;
if (!alg->cra_aead.ivsize)
return alg;
crypto_mod_put(alg);
alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
mask & ~CRYPTO_ALG_TESTED);
if (IS_ERR(alg))
return alg;
if (alg->cra_type == &crypto_aead_type) {
if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
crypto_mod_put(alg);
alg = ERR_PTR(-ENOENT);
}
return alg;
}
BUG_ON(!alg->cra_aead.ivsize);
return ERR_PTR(crypto_nivaead_default(alg, type, mask));
}
EXPORT_SYMBOL_GPL(crypto_lookup_aead);
int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;
type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
mask |= CRYPTO_ALG_TYPE_MASK;
alg = crypto_lookup_aead(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);
err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_aead);
struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
{
struct crypto_tfm *tfm;
int err;
type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
type |= CRYPTO_ALG_TYPE_AEAD;
mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
mask |= CRYPTO_ALG_TYPE_MASK;
for (;;) {
struct crypto_alg *alg;
alg = crypto_lookup_aead(alg_name, type, mask);
if (IS_ERR(alg)) {
err = PTR_ERR(alg);
goto err;
}
tfm = __crypto_alloc_tfm(alg, type, mask);
if (!IS_ERR(tfm))
return __crypto_aead_cast(tfm);
crypto_mod_put(alg);
err = PTR_ERR(tfm);
err:
if (err != -EAGAIN)
break;
if (signal_pending(current)) {
err = -EINTR;
break;
}
}
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_aead);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
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