================================================================== BUG: KASAN: slab-use-after-free in super_90_validate+0x178b/0x18c0 drivers/md/md.c:1592 Read of size 4 at addr ffff88805b163390 by task syz.7.1110/10694 CPU: 0 UID: 0 PID: 10694 Comm: syz.7.1110 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 super_90_validate+0x178b/0x18c0 drivers/md/md.c:1592 add_bound_rdev+0x274/0x390 drivers/md/md.c:3012 md_add_new_disk+0xca1/0x1820 drivers/md/md.c:7666 md_ioctl+0x2cac/0x3700 drivers/md/md.c:8487 blkdev_ioctl+0x5ad/0x6f0 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:52 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4e6fda94d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4e70c24028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4e70026090 RCX: 00007f4e6fda94d9 RDX: 00002000000000c0 RSI: 0000000040140921 RDI: 000000000000002c RBP: 00007f4e6fe3804e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4e70026128 R14: 00007f4e70026090 R15: 00007ffd7b7e73a8 Allocated by task 7338: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:351 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:377 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:5033 [inline] kmem_cache_alloc_node_noprof+0x282/0x6e0 mm/slub.c:5105 __alloc_skb+0x140/0x710 net/core/skbuff.c:705 alloc_skb include/linux/skbuff.h:1390 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline] nsim_dev_trap_report_work+0x2af/0xd20 drivers/net/netdevsim/dev.c:847 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495 process_scheduled_works kernel/workqueue.c:3578 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 7338: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2780 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6757 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1137 __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb net/core/skbuff.c:1440 [inline] consume_skb+0xd1/0x110 net/core/skbuff.c:1434 nsim_dev_trap_report drivers/net/netdevsim/dev.c:817 [inline] nsim_dev_trap_report_work+0x8de/0xd20 drivers/net/netdevsim/dev.c:847 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495 process_scheduled_works kernel/workqueue.c:3578 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88805b1632c0 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 208 bytes inside of freed 240-byte region [ffff88805b1632c0, ffff88805b1633b0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805b163400 pfn:0x5b162 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff8881006d6140 ffffea0000b27410 ffffea00015af510 raw: ffff88805b163400 0000000200190010 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff8881006d6140 ffffea0000b27410 ffffea00015af510 head: ffff88805b163400 0000000200190010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 8738, tgid 8737 (syz.5.663), ts 120362486718 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1860 prep_new_page mm/page_alloc.c:1868 [inline] get_page_from_freelist+0xdae/0x2c80 mm/page_alloc.c:3950 __alloc_frozen_pages_noprof+0x2ad/0x31e0 mm/page_alloc.c:5492 alloc_slab_page mm/slub.c:3384 [inline] allocate_slab mm/slub.c:3499 [inline] new_slab+0xb1/0x6d0 mm/slub.c:3550 refill_objects+0xe3/0x410 mm/slub.c:7539 refill_sheaf mm/slub.c:2917 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811 alloc_from_pcs mm/slub.c:4887 [inline] slab_alloc_node mm/slub.c:5021 [inline] kmem_cache_alloc_node_noprof+0x4ed/0x6e0 mm/slub.c:5105 __alloc_skb+0x140/0x710 net/core/skbuff.c:705 alloc_skb include/linux/skbuff.h:1390 [inline] alloc_uevent_skb+0x7d/0x210 lib/kobject_uevent.c:289 uevent_net_broadcast_tagged lib/kobject_uevent.c:352 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:415 [inline] kobject_uevent_env+0x122c/0x18b0 lib/kobject_uevent.c:611 register_netdevice+0x1b3a/0x26b0 net/core/dev.c:11791 tun_set_iff drivers/net/tun.c:2988 [inline] __tun_chr_ioctl+0x1e6e/0x4970 drivers/net/tun.c:3271 vfs_ioctl fs/ioctl.c:52 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x7b0 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 64 tgid 64 ts 120350888747 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x7b1/0x10f0 mm/page_alloc.c:2958 rcu_do_batch kernel/rcu/tree.c:2650 [inline] rcu_core+0x5f0/0x1220 kernel/rcu/tree.c:2919 handle_softirqs+0x216/0xa20 kernel/softirq.c:669 __do_softirq kernel/softirq.c:703 [inline] invoke_softirq kernel/softirq.c:542 [inline] __irq_exit_rcu+0x178/0x220 kernel/softirq.c:786 irq_exit_rcu+0x9/0x30 kernel/softirq.c:809 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 Memory state around the buggy address: ffff88805b163280: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88805b163300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805b163380: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ^ ffff88805b163400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b163480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ==================================================================