block nbd2: Device being setup by another task ldm_validate_partition_table(): Disk read failed. Dev nbd4: unable to read RDB block 0 nbd4: unable to read partition table ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 lib/refcount.c:269 Read of size 4 at addr ffff888238b99158 by task syz-executor.4/25878 CPU: 0 PID: 25878 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report+0x8f/0xa0 mm/kasan/report.c:412 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_dec_not_one+0x71/0x1d0 lib/refcount.c:269 refcount_dec_and_mutex_lock+0x1c/0x80 lib/refcount.c:308 nbd_put drivers/block/nbd.c:228 [inline] nbd_genl_connect+0x11ee/0x1630 drivers/block/nbd.c:1913 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f7217029639 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f721557b168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f721714a050 RCX: 00007f7217029639 RDX: 0000000000000000 RSI: 0000000020000380 RDI: 000000000000000e RBP: 00007f7217084a41 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeb95c92cf R14: 00007f721557b300 R15: 0000000000022000 Allocated by task 1: kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] nbd_dev_add+0x44/0x890 drivers/block/nbd.c:1627 nbd_init+0x1a7/0x1c7 drivers/block/nbd.c:2321 do_one_initcall+0xf1/0x740 init/main.c:884 do_initcall_level init/main.c:952 [inline] do_initcalls init/main.c:960 [inline] do_basic_setup init/main.c:978 [inline] kernel_init_freeable+0x9c5/0xab7 init/main.c:1145 kernel_init+0xd/0x1ba init/main.c:1062 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Freed by task 25878: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 nbd_dev_remove drivers/block/nbd.c:223 [inline] nbd_put.part.0+0xfe/0x140 drivers/block/nbd.c:231 nbd_put drivers/block/nbd.c:275 [inline] nbd_config_put+0x6a0/0x870 drivers/block/nbd.c:1185 nbd_genl_connect+0x11bb/0x1630 drivers/block/nbd.c:1911 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888238b99080 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 216 bytes inside of 512-byte region [ffff888238b99080, ffff888238b99280) The buggy address belongs to the page: page:ffffea0008e2e640 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 flags: 0x57ff00000000100(slab) raw: 057ff00000000100 ffffea0008e2c348 ffffea0008e2edc8 ffff88813bff0940 raw: 0000000000000000 ffff888238b99080 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888238b99000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888238b99080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888238b99100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888238b99180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888238b99200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================