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>
98c598afc2