================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007 Read of size 8 at addr ffff888012ebb018 by task syz.2.17/5514 CPU: 0 UID: 0 PID: 5514 Comm: syz.2.17 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #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 16 61 5e f6 48 89 df e8 1e de 5e f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 5a 50 f6 65 8b 05 16 f9 f8 74 85 c0 74 16 5b RSP: 0018:ffffc9000428f108 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff9a493bc8 RCX: 1ffffffff2023449 RDX: 0000000000000000 RSI: ffffffff8b4cd060 RDI: ffffffff8bb07fe0 RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9011e69f R11: 0000000000000000 R12: ffff88805594b000 R13: 0000000000000002 R14: 0000000000000002 R15: ffff88805594b000 __debug_check_no_obj_freed lib/debugobjects.c:999 [inline] debug_check_no_obj_freed+0x328/0x600 lib/debugobjects.c:1020 free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_folios+0x386/0x1390 mm/page_alloc.c:2667 folios_put_refs+0x560/0x760 mm/swap.c:1039 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x5a1/0x1160 mm/shmem.c:1023 shmem_truncate_range mm/shmem.c:1132 [inline] shmem_evict_inode+0x3a3/0xba0 mm/shmem.c:1260 evict+0x398/0x8c0 fs/inode.c:704 iput_final fs/inode.c:1838 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1864 iput+0x5c/0x80 fs/inode.c:1854 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:412 __dentry_kill+0x1d0/0x600 fs/dcache.c:615 dput.part.0+0x4b1/0x9b0 fs/dcache.c:857 dput+0x1f/0x30 fs/dcache.c:847 __fput+0x54e/0xbb0 fs/file_table.c:430 task_work_run+0x14e/0x250 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xaa3/0x2bb0 kernel/exit.c:882 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x2658/0x26d0 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fe5579 Code: Unable to access opcode bytes at 0xf7fe554f. RSP: 002b:00000000f573456c EFLAGS: 00000296 ORIG_RAX: 0000000000000151 RAX: 0000000000010106 RBX: 0000000000000007 RCX: 00000000200000c0 RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 5537: 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 5537: 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:2256 [inline] slab_free mm/slub.c:4477 [inline] kfree+0x12a/0x3b0 mm/slub.c:4598 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 ffff888012ebb000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888012ebb000, ffff888012ebb200) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12eb8 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000002 ffffea00004bae01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 11, tgid 11 (kworker/u32:0), ts 53895131217, free_ts 51781759407 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500 prep_new_page mm/page_alloc.c:1508 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3446 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702 __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:2325 allocate_slab mm/slub.c:2488 [inline] new_slab+0x84/0x260 mm/slub.c:2541 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817 __slab_alloc_node mm/slub.c:3870 [inline] slab_alloc_node mm/slub.c:4029 [inline] __do_kmalloc_node mm/slub.c:4161 [inline] __kmalloc_noprof+0x379/0x410 mm/slub.c:4174 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_prefix_route+0x2fe/0x510 net/ipv6/addrconf.c:2486 addrconf_add_linklocal+0x32a/0x620 net/ipv6/addrconf.c:3317 addrconf_addr_gen+0x37b/0x3d0 net/ipv6/addrconf.c:3446 addrconf_dev_config net/ipv6/addrconf.c:3492 [inline] addrconf_init_auto_addrs+0x446/0x820 net/ipv6/addrconf.c:3570 addrconf_notify+0x6ef/0x19d0 net/ipv6/addrconf.c:3743 page last free pid 5351 tgid 5351 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2619 __put_partials+0x14c/0x170 mm/slub.c:3055 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3992 [inline] slab_alloc_node mm/slub.c:4041 [inline] kmem_cache_alloc_node_noprof+0x153/0x310 mm/slub.c:4084 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:664 alloc_skb include/linux/skbuff.h:1320 [inline] netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1206 netlink_sendmsg+0x689/0xd70 net/netlink/af_netlink.c:1876 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2204 __do_compat_sys_socketcall+0x5e2/0x700 net/compat.c:475 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 Memory state around the buggy address: ffff888012ebaf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888012ebaf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888012ebb000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888012ebb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888012ebb100: 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 16 61 5e f6 call 0xf65e6129 13: 48 89 df mov %rbx,%rdi 16: e8 1e de 5e f6 call 0xf65ede39 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 e5 5a 50 f6 call 0xf6505b19 34: 65 8b 05 16 f9 f8 74 mov %gs:0x74f8f916(%rip),%eax # 0x74f8f951 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx