================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007 Read of size 8 at addr ffff888000cc9818 by task syz-executor/5467 CPU: 0 UID: 0 PID: 5467 Comm: syz-executor Not tainted 6.11.0-rc4-syzkaller-00255-gd2bafcf224f3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:397 [inline] p9_req_put net/9p/client.c:405 [inline] p9_req_put+0xaf/0x250 net/9p/client.c:402 req_done+0x1e7/0x2f0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2595 [inline] vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2570 __handle_irq_event_percpu+0x229/0x7c0 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x263/0xd10 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285 common_interrupt+0xab/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 f6 27 61 f6 48 89 df e8 ee a4 61 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 c5 21 53 f6 65 8b 05 16 bd fb 74 85 c0 74 16 5b RSP: 0018:ffffc9000321fc10 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888023c5ae40 RCX: 1ffffffff2021fd9 RDX: 0000000000000000 RSI: ffffffff8b4cd020 RDI: ffffffff8bb055e0 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9011431f R11: ffff88802c328a40 R12: 1ffff92000643f8a R13: ffff888027e14000 R14: ffff888023c5a6f0 R15: ffff88802c33fb58 task_rq_unlock kernel/sched/sched.h:1689 [inline] wake_up_new_task+0x7b5/0xd30 kernel/sched/core.c:4703 kernel_clone+0x5fd/0x960 kernel/fork.c:2831 __do_compat_sys_ia32_clone+0xb7/0x100 arch/x86/kernel/sys_ia32.c:254 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f21579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ffca32fc EFLAGS: 00000292 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000056a424a8 RBP: 00000000f73b0ff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7618: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:681 [inline] p9_client_create+0xcf/0x11b0 net/9p/client.c:983 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1800 do_new_mount fs/namespace.c:3472 [inline] path_mount+0x6e1/0x1f10 fs/namespace.c:3799 do_mount fs/namespace.c:3812 [inline] __do_sys_mount fs/namespace.c:4020 [inline] __se_sys_mount fs/namespace.c:3997 [inline] __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 7618: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x12a/0x3b0 mm/slub.c:4594 p9_client_create+0x9ca/0x11b0 net/9p/client.c:1054 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1800 do_new_mount fs/namespace.c:3472 [inline] path_mount+0x6e1/0x1f10 fs/namespace.c:3799 do_mount fs/namespace.c:3812 [inline] __do_sys_mount fs/namespace.c:4020 [inline] __se_sys_mount fs/namespace.c:3997 [inline] __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888000cc9800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888000cc9800, ffff888000cc9a00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xcc8 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0x7ff00000000040(head|node=0|zone=0|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 007ff00000000040 ffff888015842c80 ffffea0000ad6700 dead000000000003 raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 007ff00000000040 ffff888015842c80 ffffea0000ad6700 dead000000000003 head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 007ff00000000002 ffffea0000033201 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5463, tgid 5463 (syz-executor), ts 87800381473, free_ts 87597042558 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3439 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x4e/0xf0 mm/slub.c:2321 allocate_slab mm/slub.c:2484 [inline] new_slab+0x84/0x260 mm/slub.c:2537 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_noprof+0x379/0x410 mm/slub.c:4170 kmalloc_noprof include/linux/slab.h:685 [inline] kzalloc_noprof include/linux/slab.h:807 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1aa0 net/ipv6/route.c:3761 ip6_route_add+0x26/0x1c0 net/ipv6/route.c:3853 addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2550 addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2568 addrconf_dev_config net/ipv6/addrconf.c:3482 [inline] addrconf_init_auto_addrs+0x380/0x820 net/ipv6/addrconf.c:3570 addrconf_notify+0xe9e/0x19d0 net/ipv6/addrconf.c:3743 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 page last free pid 113 tgid 113 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_folios+0x9e9/0x1390 mm/page_alloc.c:2660 shrink_folio_list+0x3584/0x41e0 mm/vmscan.c:1463 evict_folios+0x6e0/0x1b30 mm/vmscan.c:4580 try_to_shrink_lruvec+0x612/0x9b0 mm/vmscan.c:4775 shrink_one+0x3e3/0x7b0 mm/vmscan.c:4813 shrink_many mm/vmscan.c:4876 [inline] lru_gen_shrink_node+0x69f/0x1510 mm/vmscan.c:4954 shrink_node mm/vmscan.c:5934 [inline] kswapd_shrink_node mm/vmscan.c:6762 [inline] balance_pgdat+0x110f/0x1950 mm/vmscan.c:6954 kswapd+0x5ea/0xbf0 mm/vmscan.c:7223 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff888000cc9700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888000cc9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888000cc9800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888000cc9880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888000cc9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 f6 27 61 f6 call 0xf6612809 13: 48 89 df mov %rbx,%rdi 16: e8 ee a4 61 f6 call 0xf661a509 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 c5 21 53 f6 call 0xf65321f9 34: 65 8b 05 16 bd fb 74 mov %gs:0x74fbbd16(%rip),%eax # 0x74fbbd51 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx