diff options
author | Li Nan <linan122@huawei.com> | 2023-09-11 10:33:08 +0800 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2023-11-21 07:42:04 -0700 |
commit | 98c598afc22d4e43c2ad91860b65996d0c099a5d (patch) | |
tree | aaf786b94e2bd128a5c4ad559a5970dc265da6ec | |
parent | db46cd1e0426f52999d50fa72cfa97fa39952885 (diff) | |
download | linux-98c598afc22d4e43c2ad91860b65996d0c099a5d.tar.gz linux-98c598afc22d4e43c2ad91860b65996d0c099a5d.tar.bz2 linux-98c598afc22d4e43c2ad91860b65996d0c099a5d.zip |
nbd: pass nbd_sock to nbd_read_reply() instead of index
If a socket is processing ioctl 'NBD_SET_SOCK', config->socks might be
krealloc in nbd_add_socket(), and a garbage request is received now, a UAF
may occurs.
T1
nbd_ioctl
__nbd_ioctl
nbd_add_socket
blk_mq_freeze_queue
T2
recv_work
nbd_read_reply
sock_xmit
krealloc config->socks
def config->socks
Pass nbd_sock to nbd_read_reply(). And introduce a new function
sock_xmit_recv(), which differs from sock_xmit only in the way it get
socket.
==================================================================
BUG: KASAN: use-after-free in sock_xmit+0x525/0x550
Read of size 8 at addr ffff8880188ec428 by task kworker/u12:1/18779
Workqueue: knbd4-recv recv_work
Call Trace:
__dump_stack
dump_stack+0xbe/0xfd
print_address_description.constprop.0+0x19/0x170
__kasan_report.cold+0x6c/0x84
kasan_report+0x3a/0x50
sock_xmit+0x525/0x550
nbd_read_reply+0xfe/0x2c0
recv_work+0x1c2/0x750
process_one_work+0x6b6/0xf10
worker_thread+0xdd/0xd80
kthread+0x30a/0x410
ret_from_fork+0x22/0x30
Allocated by task 18784:
kasan_save_stack+0x1b/0x40
kasan_set_track
set_alloc_info
__kasan_kmalloc
__kasan_kmalloc.constprop.0+0xf0/0x130
slab_post_alloc_hook
slab_alloc_node
slab_alloc
__kmalloc_track_caller+0x157/0x550
__do_krealloc
krealloc+0x37/0xb0
nbd_add_socket
+0x2d3/0x880
__nbd_ioctl
nbd_ioctl+0x584/0x8e0
__blkdev_driver_ioctl
blkdev_ioctl+0x2a0/0x6e0
block_ioctl+0xee/0x130
vfs_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x138/0x190
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x61/0xc6
Freed by task 18784:
kasan_save_stack+0x1b/0x40
kasan_set_track+0x1c/0x30
kasan_set_free_info+0x20/0x40
__kasan_slab_free.part.0+0x13f/0x1b0
slab_free_hook
slab_free_freelist_hook
slab_free
kfree+0xcb/0x6c0
krealloc+0x56/0xb0
nbd_add_socket+0x2d3/0x880
__nbd_ioctl
nbd_ioctl+0x584/0x8e0
__blkdev_driver_ioctl
blkdev_ioctl+0x2a0/0x6e0
block_ioctl+0xee/0x130
vfs_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x138/0x190
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x61/0xc6
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230911023308.3467802-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | drivers/block/nbd.c | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 3f03cb3dc33c..b6414e1e645b 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -67,6 +67,7 @@ struct nbd_sock { struct recv_thread_args { struct work_struct work; struct nbd_device *nbd; + struct nbd_sock *nsock; int index; }; @@ -505,15 +506,9 @@ done: return BLK_EH_DONE; } -/* - * Send or receive packet. Return a positive value on success and - * negtive value on failue, and never return 0. - */ -static int sock_xmit(struct nbd_device *nbd, int index, int send, - struct iov_iter *iter, int msg_flags, int *sent) +static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send, + struct iov_iter *iter, int msg_flags, int *sent) { - struct nbd_config *config = nbd->config; - struct socket *sock = config->socks[index]->sock; int result; struct msghdr msg; unsigned int noreclaim_flag; @@ -557,6 +552,19 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send, } /* + * Send or receive packet. Return a positive value on success and + * negtive value on failure, and never return 0. + */ +static int sock_xmit(struct nbd_device *nbd, int index, int send, + struct iov_iter *iter, int msg_flags, int *sent) +{ + struct nbd_config *config = nbd->config; + struct socket *sock = config->socks[index]->sock; + + return __sock_xmit(nbd, sock, send, iter, msg_flags, sent); +} + +/* * Different settings for sk->sk_sndtimeo can result in different return values * if there is a signal pending when we enter sendmsg, because reasons? */ @@ -712,7 +720,7 @@ out: return 0; } -static int nbd_read_reply(struct nbd_device *nbd, int index, +static int nbd_read_reply(struct nbd_device *nbd, struct socket *sock, struct nbd_reply *reply) { struct kvec iov = {.iov_base = reply, .iov_len = sizeof(*reply)}; @@ -721,7 +729,7 @@ static int nbd_read_reply(struct nbd_device *nbd, int index, reply->magic = 0; iov_iter_kvec(&to, ITER_DEST, &iov, 1, sizeof(*reply)); - result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL); + result = __sock_xmit(nbd, sock, 0, &to, MSG_WAITALL, NULL); if (result < 0) { if (!nbd_disconnected(nbd->config)) dev_err(disk_to_dev(nbd->disk), @@ -845,14 +853,14 @@ static void recv_work(struct work_struct *work) struct nbd_device *nbd = args->nbd; struct nbd_config *config = nbd->config; struct request_queue *q = nbd->disk->queue; - struct nbd_sock *nsock; + struct nbd_sock *nsock = args->nsock; struct nbd_cmd *cmd; struct request *rq; while (1) { struct nbd_reply reply; - if (nbd_read_reply(nbd, args->index, &reply)) + if (nbd_read_reply(nbd, nsock->sock, &reply)) break; /* @@ -887,7 +895,6 @@ static void recv_work(struct work_struct *work) percpu_ref_put(&q->q_usage_counter); } - nsock = config->socks[args->index]; mutex_lock(&nsock->tx_lock); nbd_mark_nsock_dead(nbd, nsock, 1); mutex_unlock(&nsock->tx_lock); @@ -1231,6 +1238,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) INIT_WORK(&args->work, recv_work); args->index = i; args->nbd = nbd; + args->nsock = nsock; nsock->cookie++; mutex_unlock(&nsock->tx_lock); sockfd_put(old); @@ -1413,6 +1421,7 @@ static int nbd_start_device(struct nbd_device *nbd) refcount_inc(&nbd->config_refs); INIT_WORK(&args->work, recv_work); args->nbd = nbd; + args->nsock = config->socks[i]; args->index = i; queue_work(nbd->recv_workq, &args->work); } |