From 553768d1169a48c0cd87c4eb4ab57534ee663415 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Wed, 29 May 2019 15:16:05 -0500 Subject: [PATCH] nbd: fix crash when the blksize is zero This will allow the blksize to be set zero and then use 1024 as default. Reviewed-by: Josef Bacik Signed-off-by: Xiubo Li [fix to use goto out instead of return in genl_connect] Signed-off-by: Mike Christie Signed-off-by: Jens Axboe --- drivers/block/nbd.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 3a9bca3..5c4e3f2 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -134,6 +134,8 @@ static struct dentry *nbd_dbg_dir; #define NBD_MAGIC 0x68797548 +#define NBD_DEF_BLKSIZE 1024 + static unsigned int nbds_max = 16; static int max_part = 16; static struct workqueue_struct *recv_workqueue; @@ -1236,6 +1238,14 @@ static void nbd_clear_sock_ioctl(struct nbd_device *nbd, nbd_config_put(nbd); } +static bool nbd_is_valid_blksize(unsigned long blksize) +{ + if (!blksize || !is_power_of_2(blksize) || blksize < 512 || + blksize > PAGE_SIZE) + return false; + return true; +} + /* Must be called with config_lock held */ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, unsigned int cmd, unsigned long arg) @@ -1251,8 +1261,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, case NBD_SET_SOCK: return nbd_add_socket(nbd, arg, false); case NBD_SET_BLKSIZE: - if (!arg || !is_power_of_2(arg) || arg < 512 || - arg > PAGE_SIZE) + if (!arg) + arg = NBD_DEF_BLKSIZE; + if (!nbd_is_valid_blksize(arg)) return -EINVAL; nbd_size_set(nbd, arg, div_s64(config->bytesize, arg)); @@ -1332,7 +1343,7 @@ static struct nbd_config *nbd_alloc_config(void) atomic_set(&config->recv_threads, 0); init_waitqueue_head(&config->recv_wq); init_waitqueue_head(&config->conn_wait); - config->blksize = 1024; + config->blksize = NBD_DEF_BLKSIZE; atomic_set(&config->live_connections, 0); try_module_get(THIS_MODULE); return config; @@ -1768,6 +1779,12 @@ again: if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]) { u64 bsize = nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]); + if (!bsize) + bsize = NBD_DEF_BLKSIZE; + if (!nbd_is_valid_blksize(bsize)) { + ret = -EINVAL; + goto out; + } nbd_size_set(nbd, bsize, div64_u64(config->bytesize, bsize)); } if (info->attrs[NBD_ATTR_TIMEOUT]) { -- 2.7.4