Hello, syzbot found the following issue on: HEAD commit: 3770333b3f8c Add linux-next specific files for 20220106 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=171aa4e3b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=f9eb40d9f910b474 dashboard link: https://syzkaller.appspot.com/bug?extid=4f789823c1abc5accf13 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12b08f53b00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4f789823c1abc5accf13@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in rcu_seq_snap kernel/rcu/rcu.h:91 [inline] BUG: KASAN: use-after-free in srcu_invoke_callbacks+0x391/0x3c0 kernel/rcu/srcutree.c:1283 Read of size 8 at addr ffff8880189b6968 by task kworker/0:1/7 CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.16.0-rc8-next-20220106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp srcu_invoke_callbacks Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xa5/0x3ed mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 rcu_seq_snap kernel/rcu/rcu.h:91 [inline] srcu_invoke_callbacks+0x391/0x3c0 kernel/rcu/srcutree.c:1283 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Allocated by task 19830: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:738 [inline] slab_alloc_node mm/slub.c:3230 [inline] kmem_cache_alloc_node+0x255/0x3e0 mm/slub.c:3266 blk_alloc_queue+0x5ad/0x870 block/blk-core.c:446 blk_mq_init_queue_data block/blk-mq.c:3878 [inline] __blk_mq_alloc_disk+0x8c/0x1c0 block/blk-mq.c:3902 nbd_dev_add+0x3b2/0xcd0 drivers/block/nbd.c:1765 nbd_genl_connect+0x11f3/0x1930 drivers/block/nbd.c:1948 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 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+0x533/0x7d0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2410 ___sys_sendmsg+0xf3/0x170 net/socket.c:2464 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2493 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 13: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xdb/0x3b0 mm/slub.c:3526 rcu_do_batch kernel/rcu/tree.c:2536 [inline] rcu_core+0x7b8/0x1540 kernel/rcu/tree.c:2787 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x99/0x730 kernel/rcu/tree.c:3072 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 disk_release+0x19a/0x260 block/genhd.c:1116 device_release+0x9f/0x240 drivers/base/core.c:2229 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 put_device+0x1b/0x30 drivers/base/core.c:3512 put_disk block/genhd.c:1368 [inline] blk_cleanup_disk+0x6b/0x80 block/genhd.c:1384 nbd_dev_remove+0x44/0xf0 drivers/block/nbd.c:253 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x370 kernel/workqueue.c:1368 __queue_work+0x5ca/0xf30 kernel/workqueue.c:1534 __queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1682 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1718 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff8880189b5c70 which belongs to the cache request_queue_srcu of size 3816 The buggy address is located 3320 bytes inside of 3816-byte region [ffff8880189b5c70, ffff8880189b6b58) The buggy address belongs to the page: page:ffffea0000626c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x189b0 head:ffffea0000626c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888012787140 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 14963, ts 196854875504, free_ts 196839673140 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f40 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5381 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x28d/0x380 mm/slub.c:2004 ___slab_alloc+0x6be/0xd60 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] kmem_cache_alloc_node+0x122/0x3e0 mm/slub.c:3266 blk_alloc_queue+0x5ad/0x870 block/blk-core.c:446 blk_mq_init_queue_data block/blk-mq.c:3878 [inline] __blk_mq_alloc_disk+0x8c/0x1c0 block/blk-mq.c:3902 nbd_dev_add+0x3b2/0xcd0 drivers/block/nbd.c:1765 nbd_genl_connect+0x11f3/0x1930 drivers/block/nbd.c:1948 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 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+0x533/0x7d0 net/netlink/af_netlink.c:1343 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x414/0xb60 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2536 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:738 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x1e7/0x340 mm/slub.c:4420 kmalloc include/linux/slab.h:586 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1326 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0x164/0x390 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat+0x96/0x120 fs/stat.c:412 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff8880189b6800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880189b6880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880189b6900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880189b6980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880189b6a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
