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Commit aaef3170 authored by Ilya Dryomov's avatar Ilya Dryomov
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libceph: do not crash on large auth tickets 

Large (greater than 32k, the value of PAGE_ALLOC_COSTLY_ORDER) auth
tickets will have their buffers vmalloc'ed, which leads to the
following crash in crypto:

[   28.685082] BUG: unable to handle kernel paging request at ffffeb04000032c0
[   28.686032] IP: [<ffffffff81392b42>] scatterwalk_pagedone+0x22/0x80
[   28.686032] PGD 0
[   28.688088] Oops: 0000 [#1] PREEMPT SMP
[   28.688088] Modules linked in:
[   28.688088] CPU: 0 PID: 878 Comm: kworker/0:2 Not tainted 3.17.0-vm+ #305
[   28.688088] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   28.688088] Workqueue: ceph-msgr con_work
[   28.688088] task: ffff88011a7f9030 ti: ffff8800d903c000 task.ti: ffff8800d903c000
[   28.688088] RIP: 0010:[<ffffffff81392b42>]  [<ffffffff81392b42>] scatterwalk_pagedone+0x22/0x80
[   28.688088] RSP: 0018:ffff8800d903f688  EFLAGS: 00010286
[   28.688088] RAX: ffffeb04000032c0 RBX: ffff8800d903f718 RCX: ffffeb04000032c0
[   28.688088] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8800d903f750
[   28.688088] RBP: ffff8800d903f688 R08: 00000000000007de R09: ffff8800d903f880
[   28.688088] R10: 18df467c72d6257b R11: 0000000000000000 R12: 0000000000000010
[   28.688088] R13: ffff8800d903f750 R14: ffff8800d903f8a0 R15: 0000000000000000
[   28.688088] FS:  00007f50a41c7700(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000
[   28.688088] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   28.688088] CR2: ffffeb04000032c0 CR3: 00000000da3f3000 CR4: 00000000000006b0
[   28.688088] Stack:
[   28.688088]  ffff8800d903f698 ffffffff81392ca8 ffff8800d903f6e8 ffffffff81395d32
[   28.688088]  ffff8800dac96000 ffff880000000000 ffff8800d903f980 ffff880119b7e020
[   28.688088]  ffff880119b7e010 0000000000000000 0000000000000010 0000000000000010
[   28.688088] Call Trace:
[   28.688088]  [<ffffffff81392ca8>] scatterwalk_done+0x38/0x40
[   28.688088]  [<ffffffff81392ca8>] scatterwalk_done+0x38/0x40
[   28.688088]  [<ffffffff81395d32>] blkcipher_walk_done+0x182/0x220
[   28.688088]  [<ffffffff813990bf>] crypto_cbc_encrypt+0x15f/0x180
[   28.688088]  [<ffffffff81399780>] ? crypto_aes_set_key+0x30/0x30
[   28.688088]  [<ffffffff8156c40c>] ceph_aes_encrypt2+0x29c/0x2e0
[   28.688088]  [<ffffffff8156d2a3>] ceph_encrypt2+0x93/0xb0
[   28.688088]  [<ffffffff8156d7da>] ceph_x_encrypt+0x4a/0x60
[   28.688088]  [<ffffffff8155b39d>] ? ceph_buffer_new+0x5d/0xf0
[   28.688088]  [<ffffffff8156e837>] ceph_x_build_authorizer.isra.6+0x297/0x360
[   28.688088]  [<ffffffff8112089b>] ? kmem_cache_alloc_trace+0x11b/0x1c0
[   28.688088]  [<ffffffff8156b496>] ? ceph_auth_create_authorizer+0x36/0x80
[   28.688088]  [<ffffffff8156ed83>] ceph_x_create_authorizer+0x63/0xd0
[   28.688088]  [<ffffffff8156b4b4>] ceph_auth_create_authorizer+0x54/0x80
[   28.688088]  [<ffffffff8155f7c0>] get_authorizer+0x80/0xd0
[   28.688088]  [<ffffffff81555a8b>] prepare_write_connect+0x18b/0x2b0
[   28.688088]  [<ffffffff81559289>] try_read+0x1e59/0x1f10

This is because we set up crypto scatterlists as if all buffers were
kmalloc'ed.  Fix it.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarIlya Dryomov <idryomov@redhat.com>
Reviewed-by: default avatarSage Weil <sage@redhat.com>
parent 3231300b
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Inline Side-by-side
Showing with 132 additions and 37 deletions
net/ceph/crypto.c
View file @ aaef3170
......@@ -90,11 +90,82 @@ static struct crypto_blkcipher *ceph_crypto_alloc_cipher(void)
static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
/*
* Should be used for buffers allocated with ceph_kvmalloc().
* Currently these are encrypt out-buffer (ceph_buffer) and decrypt
* in-buffer (msg front).
*
* Dispose of @sgt with teardown_sgtable().
*
* @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
* in cases where a single sg is sufficient. No attempt to reduce the
* number of sgs by squeezing physically contiguous pages together is
* made though, for simplicity.
*/
static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
const void *buf, unsigned int buf_len)
{
struct scatterlist *sg;
const bool is_vmalloc = is_vmalloc_addr(buf);
unsigned int off = offset_in_page(buf);
unsigned int chunk_cnt = 1;
unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
int i;
int ret;
if (buf_len == 0) {
memset(sgt, 0, sizeof(*sgt));
return -EINVAL;
}
if (is_vmalloc) {
chunk_cnt = chunk_len >> PAGE_SHIFT;
chunk_len = PAGE_SIZE;
}
if (chunk_cnt > 1) {
ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
if (ret)
return ret;
} else {
WARN_ON(chunk_cnt != 1);
sg_init_table(prealloc_sg, 1);
sgt->sgl = prealloc_sg;
sgt->nents = sgt->orig_nents = 1;
}
for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
struct page *page;
unsigned int len = min(chunk_len - off, buf_len);
if (is_vmalloc)
page = vmalloc_to_page(buf);
else
page = virt_to_page(buf);
sg_set_page(sg, page, len, off);
off = 0;
buf += len;
buf_len -= len;
}
WARN_ON(buf_len != 0);
return 0;
}
static void teardown_sgtable(struct sg_table *sgt)
{
if (sgt->orig_nents > 1)
sg_free_table(sgt);
}
static int ceph_aes_encrypt(const void *key, int key_len,
void *dst, size_t *dst_len,
const void *src, size_t src_len)
{
struct scatterlist sg_in[2], sg_out[1];
struct scatterlist sg_in[2], prealloc_sg;
struct sg_table sg_out;
struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
int ret;
......@@ -110,16 +181,18 @@ static int ceph_aes_encrypt(const void *key, int key_len,
*dst_len = src_len + zero_padding;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
sg_init_table(sg_in, 2);
sg_set_buf(&sg_in[0], src, src_len);
sg_set_buf(&sg_in[1], pad, zero_padding);
sg_init_table(sg_out, 1);
sg_set_buf(sg_out, dst, *dst_len);
ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
if (ret)
goto out_tfm;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
iv = crypto_blkcipher_crt(tfm)->iv;
ivsize = crypto_blkcipher_ivsize(tfm);
memcpy(iv, aes_iv, ivsize);
/*
print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1,
key, key_len, 1);
......@@ -128,16 +201,22 @@ static int ceph_aes_encrypt(const void *key, int key_len,
print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1,
pad, zero_padding, 1);
*/
ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in,
ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
src_len + zero_padding);
crypto_free_blkcipher(tfm);
if (ret < 0)
if (ret < 0) {
pr_err("ceph_aes_crypt failed %d\n", ret);
goto out_sg;
}
/*
print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1,
dst, *dst_len, 1);
*/
return 0;
out_sg:
teardown_sgtable(&sg_out);
out_tfm:
crypto_free_blkcipher(tfm);
return ret;
}
static int ceph_aes_encrypt2(const void *key, int key_len, void *dst,
......@@ -145,7 +224,8 @@ static int ceph_aes_encrypt2(const void *key, int key_len, void *dst,
const void *src1, size_t src1_len,
const void *src2, size_t src2_len)
{
struct scatterlist sg_in[3], sg_out[1];
struct scatterlist sg_in[3], prealloc_sg;
struct sg_table sg_out;
struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
int ret;
......@@ -161,17 +241,19 @@ static int ceph_aes_encrypt2(const void *key, int key_len, void *dst,
*dst_len = src1_len + src2_len + zero_padding;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
sg_init_table(sg_in, 3);
sg_set_buf(&sg_in[0], src1, src1_len);
sg_set_buf(&sg_in[1], src2, src2_len);
sg_set_buf(&sg_in[2], pad, zero_padding);
sg_init_table(sg_out, 1);
sg_set_buf(sg_out, dst, *dst_len);
ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
if (ret)
goto out_tfm;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
iv = crypto_blkcipher_crt(tfm)->iv;
ivsize = crypto_blkcipher_ivsize(tfm);
memcpy(iv, aes_iv, ivsize);
/*
print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1,
key, key_len, 1);
......@@ -182,23 +264,30 @@ static int ceph_aes_encrypt2(const void *key, int key_len, void *dst,
print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1,
pad, zero_padding, 1);
*/
ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in,
ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
src1_len + src2_len + zero_padding);
crypto_free_blkcipher(tfm);
if (ret < 0)
if (ret < 0) {
pr_err("ceph_aes_crypt2 failed %d\n", ret);
goto out_sg;
}
/*
print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1,
dst, *dst_len, 1);
*/
return 0;
out_sg:
teardown_sgtable(&sg_out);
out_tfm:
crypto_free_blkcipher(tfm);
return ret;
}
static int ceph_aes_decrypt(const void *key, int key_len,
void *dst, size_t *dst_len,
const void *src, size_t src_len)
{
struct scatterlist sg_in[1], sg_out[2];
struct sg_table sg_in;
struct scatterlist sg_out[2], prealloc_sg;
struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
struct blkcipher_desc desc = { .tfm = tfm };
char pad[16];
......@@ -210,16 +299,16 @@ static int ceph_aes_decrypt(const void *key, int key_len,
if (IS_ERR(tfm))
return PTR_ERR(tfm);
crypto_blkcipher_setkey((void *)tfm, key, key_len);
sg_init_table(sg_in, 1);
sg_init_table(sg_out, 2);
sg_set_buf(sg_in, src, src_len);
sg_set_buf(&sg_out[0], dst, *dst_len);
sg_set_buf(&sg_out[1], pad, sizeof(pad));
ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
if (ret)
goto out_tfm;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
iv = crypto_blkcipher_crt(tfm)->iv;
ivsize = crypto_blkcipher_ivsize(tfm);
memcpy(iv, aes_iv, ivsize);
/*
......@@ -228,12 +317,10 @@ static int ceph_aes_decrypt(const void *key, int key_len,
print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1,
src, src_len, 1);
*/
ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, src_len);
crypto_free_blkcipher(tfm);
ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
if (ret < 0) {
pr_err("ceph_aes_decrypt failed %d\n", ret);
return ret;
goto out_sg;
}
if (src_len <= *dst_len)
......@@ -251,7 +338,12 @@ static int ceph_aes_decrypt(const void *key, int key_len,
print_hex_dump(KERN_ERR, "dec out: ", DUMP_PREFIX_NONE, 16, 1,
dst, *dst_len, 1);
*/
return 0;
out_sg:
teardown_sgtable(&sg_in);
out_tfm:
crypto_free_blkcipher(tfm);
return ret;
}
static int ceph_aes_decrypt2(const void *key, int key_len,
......@@ -259,7 +351,8 @@ static int ceph_aes_decrypt2(const void *key, int key_len,
void *dst2, size_t *dst2_len,
const void *src, size_t src_len)
{
struct scatterlist sg_in[1], sg_out[3];
struct sg_table sg_in;
struct scatterlist sg_out[3], prealloc_sg;
struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
struct blkcipher_desc desc = { .tfm = tfm };
char pad[16];
......@@ -271,17 +364,17 @@ static int ceph_aes_decrypt2(const void *key, int key_len,
if (IS_ERR(tfm))
return PTR_ERR(tfm);
sg_init_table(sg_in, 1);
sg_set_buf(sg_in, src, src_len);
sg_init_table(sg_out, 3);
sg_set_buf(&sg_out[0], dst1, *dst1_len);
sg_set_buf(&sg_out[1], dst2, *dst2_len);
sg_set_buf(&sg_out[2], pad, sizeof(pad));
ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
if (ret)
goto out_tfm;
crypto_blkcipher_setkey((void *)tfm, key, key_len);
iv = crypto_blkcipher_crt(tfm)->iv;
ivsize = crypto_blkcipher_ivsize(tfm);
memcpy(iv, aes_iv, ivsize);
/*
......@@ -290,12 +383,10 @@ static int ceph_aes_decrypt2(const void *key, int key_len,
print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1,
src, src_len, 1);
*/
ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, src_len);
crypto_free_blkcipher(tfm);
ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
if (ret < 0) {
pr_err("ceph_aes_decrypt failed %d\n", ret);
return ret;
goto out_sg;
}
if (src_len <= *dst1_len)
......@@ -325,7 +416,11 @@ static int ceph_aes_decrypt2(const void *key, int key_len,
dst2, *dst2_len, 1);
*/
return 0;
out_sg:
teardown_sgtable(&sg_in);
out_tfm:
crypto_free_blkcipher(tfm);
return ret;
}
......
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