From: Mikulas Patocka Date: Wed, 22 Aug 2018 16:45:51 +0000 (-0400) Subject: dm verity: fix crash on bufio buffer that was allocated with vmalloc X-Git-Tag: v4.19~194^2~7 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e4b069e0945fa14c71cf8b5b89f8b1b2aa68dbc2;p=platform%2Fkernel%2Flinux-rpi3.git dm verity: fix crash on bufio buffer that was allocated with vmalloc Since commit d1ac3ff008fb ("dm verity: switch to using asynchronous hash crypto API") dm-verity uses asynchronous crypto calls for verification, so that it can use hardware with asynchronous processing of crypto operations. These asynchronous calls don't support vmalloc memory, but the buffer data can be allocated with vmalloc if dm-bufio is short of memory and uses a reserved buffer that was preallocated in dm_bufio_client_create(). Fix verity_hash_update() so that it deals with vmalloc'd memory correctly. Reported-by: "Xiao, Jin" Signed-off-by: Mikulas Patocka Fixes: d1ac3ff008fb ("dm verity: switch to using asynchronous hash crypto API") Cc: stable@vger.kernel.org # 4.12+ Signed-off-by: Mike Snitzer --- diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 12decdbd7..fc65f0d 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -99,10 +99,26 @@ static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, { struct scatterlist sg; - sg_init_one(&sg, data, len); - ahash_request_set_crypt(req, &sg, NULL, len); - - return crypto_wait_req(crypto_ahash_update(req), wait); + if (likely(!is_vmalloc_addr(data))) { + sg_init_one(&sg, data, len); + ahash_request_set_crypt(req, &sg, NULL, len); + return crypto_wait_req(crypto_ahash_update(req), wait); + } else { + do { + int r; + size_t this_step = min_t(size_t, len, PAGE_SIZE - offset_in_page(data)); + flush_kernel_vmap_range((void *)data, this_step); + sg_init_table(&sg, 1); + sg_set_page(&sg, vmalloc_to_page(data), this_step, offset_in_page(data)); + ahash_request_set_crypt(req, &sg, NULL, this_step); + r = crypto_wait_req(crypto_ahash_update(req), wait); + if (unlikely(r)) + return r; + data += this_step; + len -= this_step; + } while (len); + return 0; + } } /*