================================================================== BUG: KASAN: use-after-free in rcu_seq_snap kernel/rcu/rcu.h:91 [inline] BUG: KASAN: use-after-free in srcu_invoke_callbacks+0x2e2/0x410 kernel/rcu/srcutree.c:1284 Read of size 8 at addr ffff888069e6abc8 by task kworker/1:7/3713 CPU: 1 PID: 3713 Comm: kworker/1:7 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp srcu_invoke_callbacks Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 print_address_description+0x65/0x3a0 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report+0x19a/0x1f0 mm/kasan/report.c:459 rcu_seq_snap kernel/rcu/rcu.h:91 [inline] srcu_invoke_callbacks+0x2e2/0x410 kernel/rcu/srcutree.c:1284 process_one_work+0x850/0x1130 kernel/workqueue.c:2307 worker_thread+0xab1/0x1300 kernel/workqueue.c:2454 kthread+0x2a3/0x2d0 kernel/kthread.c:359 ret_from_fork+0x1f/0x30 Allocated by task 29212: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:437 [inline] __kasan_slab_alloc+0xb6/0xf0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] kmem_cache_alloc_node+0x201/0x370 mm/slub.c:3266 blk_alloc_queue+0x3e/0x630 block/blk-core.c:446 blk_mq_init_queue_data block/blk-mq.c:3865 [inline] __blk_mq_alloc_disk+0x81/0x1b0 block/blk-mq.c:3889 nbd_dev_add+0x360/0xab0 drivers/block/nbd.c:1765 nbd_genl_connect+0xa66/0x1f50 drivers/block/nbd.c:1948 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x1032/0x1480 net/netlink/genetlink.c:792 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2494 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x81a/0x9f0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xaec/0xe60 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmsg+0x280/0x370 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 19: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x126/0x180 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xb6/0x1c0 mm/slub.c:3526 rcu_do_batch kernel/rcu/tree.c:2527 [inline] rcu_core+0xa85/0x1700 kernel/rcu/tree.c:2778 __do_softirq+0x392/0x7a3 kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3026 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3106 kobject_cleanup+0x1c0/0x280 lib/kobject.c:705 disk_release+0x15e/0x1b0 block/genhd.c:1116 device_release+0x98/0x1c0 kobject_cleanup+0x1c0/0x280 lib/kobject.c:705 nbd_dev_remove drivers/block/nbd.c:253 [inline] nbd_dev_remove_work+0x4f/0xe0 drivers/block/nbd.c:269 process_one_work+0x850/0x1130 kernel/workqueue.c:2307 worker_thread+0xab1/0x1300 kernel/workqueue.c:2454 kthread+0x2a3/0x2d0 kernel/kthread.c:359 ret_from_fork+0x1f/0x30 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:348 insert_work+0x54/0x400 kernel/workqueue.c:1368 __queue_work+0x928/0xc60 kernel/workqueue.c:1534 queue_delayed_work_on+0x135/0x230 kernel/workqueue.c:1718 queue_delayed_work include/linux/workqueue.h:517 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:682 [inline] srcu_gp_start_if_needed+0x603/0x930 kernel/rcu/srcutree.c:838 __call_srcu kernel/rcu/srcutree.c:883 [inline] __synchronize_srcu+0x2a2/0x350 kernel/rcu/srcutree.c:929 nbd_clear_que drivers/block/nbd.c:896 [inline] nbd_clear_sock drivers/block/nbd.c:1284 [inline] nbd_config_put+0x335/0x820 drivers/block/nbd.c:1307 nbd_genl_connect+0x1bbc/0x1f50 drivers/block/nbd.c:2074 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x1032/0x1480 net/netlink/genetlink.c:792 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2494 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x81a/0x9f0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xaec/0xe60 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmsg+0x280/0x370 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888069e69ed0 which belongs to the cache request_queue_srcu of size 3816 The buggy address is located 3320 bytes inside of 3816-byte region [ffff888069e69ed0, ffff888069e6adb8) The buggy address belongs to the page: page:ffffea0001a79a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x69e68 head:ffffea0001a79a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e64400 dead000000000004 ffff8880161e0780 raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 9517, ts 131559972677, free_ts 131537591558 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0x729/0x9e0 mm/page_alloc.c:4164 __alloc_pages+0x255/0x580 mm/page_alloc.c:5386 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0xce/0x3f0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x3fe/0xc30 mm/slub.c:3018 __slab_alloc mm/slub.c:3105 [inline] slab_alloc_node mm/slub.c:3196 [inline] kmem_cache_alloc_node+0x2bb/0x370 mm/slub.c:3266 blk_alloc_queue+0x3e/0x630 block/blk-core.c:446 blk_mq_init_queue_data block/blk-mq.c:3865 [inline] __blk_mq_alloc_disk+0x81/0x1b0 block/blk-mq.c:3889 nbd_dev_add+0x360/0xab0 drivers/block/nbd.c:1765 nbd_genl_connect+0xa66/0x1f50 drivers/block/nbd.c:1948 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x1032/0x1480 net/netlink/genetlink.c:792 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2494 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x81a/0x9f0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xaec/0xe60 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmsg+0x280/0x370 net/socket.c:2496 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1351 [inline] free_pcp_prepare+0xd1c/0xe00 mm/page_alloc.c:1403 free_unref_page_prepare mm/page_alloc.c:3324 [inline] free_unref_page+0x7d/0x580 mm/page_alloc.c:3403 free_slab mm/slub.c:2043 [inline] discard_slab mm/slub.c:2049 [inline] __unfreeze_partials+0x1ab/0x200 mm/slub.c:2536 put_cpu_partial+0x116/0x180 mm/slub.c:2612 do_slab_free mm/slub.c:3497 [inline] ___cache_free+0x107/0x160 mm/slub.c:3516 qlist_free_all mm/kasan/quarantine.c:176 [inline] kasan_quarantine_reduce+0x169/0x1f0 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x1c9/0x310 mm/slub.c:3243 getname_flags+0xba/0x650 fs/namei.c:138 user_path_at_empty+0x2a/0x1a0 fs/namei.c:2800 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1779 [inline] __do_sys_umount fs/namespace.c:1787 [inline] __se_sys_umount fs/namespace.c:1785 [inline] __x64_sys_umount+0xf0/0x170 fs/namespace.c:1785 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888069e6aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888069e6ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888069e6ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888069e6ac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888069e6ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================