[PATCH openEuler-1.0-LTS 1/2] nbd: validate the block size in nbd_set_size
From: Christoph Hellwig <hch@lst.de> mainline inclusion from mainline-v5.1-rc1 commit dcbddf541f18e367ac9cdad8e223d382cd303161 category: bugfix bugzilla: 188268, https://gitee.com/openeuler/kernel/issues/I6DC67 CVE: NA ---------------------------------------- Move the validation of the block from the callers into nbd_set_size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> conflict: drivers/block/nbd.c Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/block/nbd.c | 46 +++++++++++++++++---------------------------- 1 file changed, 17 insertions(+), 29 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index a08f35946718..41bafd5094c3 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -298,16 +298,21 @@ static void nbd_size_clear(struct nbd_device *nbd) } } -static void nbd_set_size(struct nbd_device *nbd, loff_t bytesize, +static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, loff_t blksize) { struct block_device *bdev; + if (!blksize) + blksize = NBD_DEF_BLKSIZE; + if (blksize < 512 || blksize > PAGE_SIZE || !is_power_of_2(blksize)) + return -EINVAL; + nbd->config->bytesize = bytesize; nbd->config->blksize = blksize; if (!nbd->pid) - return; + return 0; if (nbd->config->flags & NBD_FLAG_SEND_TRIM) { nbd->disk->queue->limits.discard_granularity = blksize; @@ -327,6 +332,7 @@ static void nbd_set_size(struct nbd_device *nbd, loff_t bytesize, bdput(bdev); } kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); + return 0; } static void nbd_complete_rq(struct request *req) @@ -1329,8 +1335,7 @@ static int nbd_start_device(struct nbd_device *nbd) args->index = i; queue_work(nbd->recv_workq, &args->work); } - nbd_set_size(nbd, config->bytesize, config->blksize); - return error; + return nbd_set_size(nbd, config->bytesize, config->blksize); } static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *bdev) @@ -1377,14 +1382,6 @@ 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) @@ -1401,20 +1398,13 @@ 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) - arg = NBD_DEF_BLKSIZE; - if (!nbd_is_valid_blksize(arg)) - return -EINVAL; - nbd_set_size(nbd, config->bytesize, arg); - return 0; + return nbd_set_size(nbd, config->bytesize, arg); case NBD_SET_SIZE: - nbd_set_size(nbd, arg, config->blksize); - return 0; + return nbd_set_size(nbd, arg, config->blksize); case NBD_SET_SIZE_BLOCKS: if (check_mul_overflow((loff_t)arg, config->blksize, &bytesize)) return -EINVAL; - nbd_set_size(nbd, bytesize, config->blksize); - return 0; + return nbd_set_size(nbd, bytesize, config->blksize); case NBD_SET_TIMEOUT: if (arg) { nbd->tag_set.timeout = arg * HZ; @@ -1946,18 +1936,16 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) if (info->attrs[NBD_ATTR_SIZE_BYTES]) { u64 bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]); - nbd_set_size(nbd, bytes, config->blksize); + ret = nbd_set_size(nbd, bytes, config->blksize); + if (ret) + goto out; } 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; + ret = nbd_set_size(nbd, config->bytesize, bsize); + if (ret) goto out; - } - nbd_set_size(nbd, config->bytesize, bsize); } if (info->attrs[NBD_ATTR_TIMEOUT]) { u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]); -- 2.25.1
From: Zhong Jinghua <zhongjinghua@huawei.com> mainline inclusion from mainline-v6.4-rc1 commit 55793ea54d77719a071b1ccc05a05056e3b5e009 category: bugfix bugzilla: 188268, https://gitee.com/openeuler/kernel/issues/I6DC67 CVE: NA ---------------------------------------- We tested and found an alarm caused by nbd_ioctl arg without verification. The UBSAN warning calltrace like below: UBSAN: Undefined behaviour in fs/buffer.c:1709:35 signed integer overflow: -9223372036854775808 - 1 cannot be represented in type 'long long int' CPU: 3 PID: 2523 Comm: syz-executor.0 Not tainted 4.19.90 #1 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x3f0 arch/arm64/kernel/time.c:78 show_stack+0x28/0x38 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x170/0x1dc lib/dump_stack.c:118 ubsan_epilogue+0x18/0xb4 lib/ubsan.c:161 handle_overflow+0x188/0x1dc lib/ubsan.c:192 __ubsan_handle_sub_overflow+0x34/0x44 lib/ubsan.c:206 __block_write_full_page+0x94c/0xa20 fs/buffer.c:1709 block_write_full_page+0x1f0/0x280 fs/buffer.c:2934 blkdev_writepage+0x34/0x40 fs/block_dev.c:607 __writepage+0x68/0xe8 mm/page-writeback.c:2305 write_cache_pages+0x44c/0xc70 mm/page-writeback.c:2240 generic_writepages+0xdc/0x148 mm/page-writeback.c:2329 blkdev_writepages+0x2c/0x38 fs/block_dev.c:2114 do_writepages+0xd4/0x250 mm/page-writeback.c:2344 The reason for triggering this warning is __block_write_full_page() -> i_size_read(inode) - 1 overflow. inode->i_size is assigned in __nbd_ioctl() -> nbd_set_size() -> bytesize. We think it is necessary to limit the size of arg to prevent errors. Moreover, __nbd_ioctl() -> nbd_add_socket(), arg will be cast to int. Assuming the value of arg is 0x80000000000000001) (on a 64-bit machine), it will become 1 after the coercion, which will return unexpected results. Fix it by adding checks to prevent passing in too large numbers. Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/r/20230206145805.2645671-1-zhongjinghua@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/block/nbd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 41bafd5094c3..c306e9ffdd08 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -308,6 +308,9 @@ static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize, if (blksize < 512 || blksize > PAGE_SIZE || !is_power_of_2(blksize)) return -EINVAL; + if (bytesize < 0) + return -EINVAL; + nbd->config->bytesize = bytesize; nbd->config->blksize = blksize; @@ -1043,6 +1046,9 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, struct nbd_sock *nsock; int err; + /* Arg will be cast to int, check it to avoid overflow */ + if (arg > INT_MAX) + return -EINVAL; sock = nbd_get_socket(nbd, arg, &err); if (!sock) return err; -- 2.25.1
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Yongqiang Liu