This is a note to let you know that I've just added the patch titled

dm integrity: don't store cipher request on the stack

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: dm-integrity-don-t-store-cipher-request-on-the-stack.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 717f4b1c52135f279112df82583e0c77e80f90de Mon Sep 17 00:00:00 2001

From: Mikulas Patocka mpatocka@redhat.com Date: Wed, 10 Jan 2018 09:32:47 -0500 Subject: dm integrity: don't store cipher request on the stack

From: Mikulas Patocka mpatocka@redhat.com

commit 717f4b1c52135f279112df82583e0c77e80f90de upstream.

Some asynchronous cipher implementations may use DMA. The stack may be mapped in the vmalloc area that doesn't support DMA. Therefore, the cipher request and initialization vector shouldn't be on the stack.

Fix this by allocating the request and iv with kmalloc.

Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/md/dm-integrity.c | 49 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 12 deletions(-)

--- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -2558,7 +2558,8 @@ static int create_journal(struct dm_inte int r = 0; unsigned i; __u64 journal_pages, journal_desc_size, journal_tree_size; - unsigned char *crypt_data = NULL; + unsigned char *crypt_data = NULL, *crypt_iv = NULL; + struct skcipher_request *req = NULL;

ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL); ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL); @@ -2616,9 +2617,20 @@ static int create_journal(struct dm_inte

if (blocksize == 1) { struct scatterlist *sg; - SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt); - unsigned char iv[ivsize]; - skcipher_request_set_tfm(req, ic->journal_crypt); + + req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL); + if (!req) { + *error = "Could not allocate crypt request"; + r = -ENOMEM; + goto bad; + } + + crypt_iv = kmalloc(ivsize, GFP_KERNEL); + if (!crypt_iv) { + *error = "Could not allocate iv"; + r = -ENOMEM; + goto bad; + }

ic->journal_xor = dm_integrity_alloc_page_list(ic); if (!ic->journal_xor) { @@ -2640,9 +2652,9 @@ static int create_journal(struct dm_inte sg_set_buf(&sg[i], va, PAGE_SIZE); } sg_set_buf(&sg[i], &ic->commit_ids, sizeof ic->commit_ids); - memset(iv, 0x00, ivsize); + memset(crypt_iv, 0x00, ivsize);

- skcipher_request_set_crypt(req, sg, sg, PAGE_SIZE * ic->journal_pages + sizeof ic->commit_ids, iv); + skcipher_request_set_crypt(req, sg, sg, PAGE_SIZE * ic->journal_pages + sizeof ic->commit_ids, crypt_iv); init_completion(&comp.comp); comp.in_flight = (atomic_t)ATOMIC_INIT(1); if (do_crypt(true, req, &comp)) @@ -2658,10 +2670,22 @@ static int create_journal(struct dm_inte crypto_free_skcipher(ic->journal_crypt); ic->journal_crypt = NULL; } else { - SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt); - unsigned char iv[ivsize]; unsigned crypt_len = roundup(ivsize, blocksize);

+ req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL); + if (!req) { + *error = "Could not allocate crypt request"; + r = -ENOMEM; + goto bad; + } + + crypt_iv = kmalloc(ivsize, GFP_KERNEL); + if (!crypt_iv) { + *error = "Could not allocate iv"; + r = -ENOMEM; + goto bad; + } + crypt_data = kmalloc(crypt_len, GFP_KERNEL); if (!crypt_data) { *error = "Unable to allocate crypt data"; @@ -2669,8 +2693,6 @@ static int create_journal(struct dm_inte goto bad; }

- skcipher_request_set_tfm(req, ic->journal_crypt); - ic->journal_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal); if (!ic->journal_scatterlist) { *error = "Unable to allocate sg list"; @@ -2694,12 +2716,12 @@ static int create_journal(struct dm_inte struct skcipher_request *section_req; __u32 section_le = cpu_to_le32(i);

- memset(iv, 0x00, ivsize); + memset(crypt_iv, 0x00, ivsize); memset(crypt_data, 0x00, crypt_len); memcpy(crypt_data, &section_le, min((size_t)crypt_len, sizeof(section_le)));

sg_init_one(&sg, crypt_data, crypt_len); - skcipher_request_set_crypt(req, &sg, &sg, crypt_len, iv); + skcipher_request_set_crypt(req, &sg, &sg, crypt_len, crypt_iv); init_completion(&comp.comp); comp.in_flight = (atomic_t)ATOMIC_INIT(1); if (do_crypt(true, req, &comp)) @@ -2757,6 +2779,9 @@ retest_commit_id: } bad: kfree(crypt_data); + kfree(crypt_iv); + skcipher_request_free(req); + return r; }

Patches currently in stable-queue which might be from mpatocka@redhat.com are

queue-4.14/pipe-avoid-round_pipe_size-nr_pages-overflow-on-32-bit.patch queue-4.14/dm-integrity-don-t-store-cipher-request-on-the-stack.patch