================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 Read of size 1 at addr ffff888012dbc018 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 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:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:580 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5825 __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+0x1dc/0x2e0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2718 [inline] vring_interrupt+0x31e/0x400 drivers/virtio/virtio_ring.c:2693 __handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:310 [inline] __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:325 common_interrupt+0x61/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:handle_softirqs+0x1dd/0x8e0 kernel/softirq.c:608 Code: 88 6c 24 26 4c 89 7c 24 18 48 c7 c7 20 ce 8b 8b e8 68 ef e0 09 65 66 c7 05 46 54 24 12 00 00 e8 79 7c 47 00 fb bb ff ff ff ff <49> c7 c7 c0 c0 00 8e 41 0f bc dc 83 c3 01 0f 85 a4 00 00 00 e9 b1 RSP: 0018:ffffc90000007f28 EFLAGS: 00000202 RAX: 00000000001cc754 RBX: 00000000ffffffff RCX: ffffffff81c4576f RDX: 0000000000000000 RSI: ffffffff8da29704 RDI: ffffffff8bf078c0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff908251d7 R11: 0000000000000001 R12: 0000000000000280 R13: 000000000000000a R14: 1ffff92000000fed R15: fffffbfff1c12f40 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:sched_core_balance+0xa0/0xeb0 kernel/sched/core.c:6350 Code: 45 3c 8e e8 a2 2f 0d 00 e8 fd 93 d2 09 41 5b 85 c0 0f 85 31 0a 00 00 4c 89 e7 e8 eb 72 fe ff e8 16 35 39 00 fb 48 63 44 24 50 <48> c7 c3 c0 d4 a2 93 48 89 44 24 08 48 83 f8 07 0f 87 9c 0c 00 00 RSP: 0018:ffffffff8e007b00 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff88802b223f10 RCX: ffffffff81c4576f RDX: 0000000000000000 RSI: ffffffff8da29704 RDI: ffffffff8bf078c0 RBP: ffffffff8e007c20 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff908251d7 R11: 0000000000000001 R12: ffff88802b23a4c0 R13: ffff888024178000 R14: 0000000000000000 R15: dffffc0000000000 do_balance_callbacks kernel/sched/core.c:4979 [inline] __balance_callbacks kernel/sched/core.c:5033 [inline] finish_lock_switch kernel/sched/core.c:5072 [inline] finish_task_switch.isra.0+0x472/0xc10 kernel/sched/core.c:5191 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6929 schedule_idle+0x5c/0x90 kernel/sched/core.c:7052 do_idle+0x2b3/0x500 kernel/sched/idle.c:358 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 Allocated by task 6303: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] p9_client_create+0xc7/0x11d0 net/9p/client.c:985 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663 vfs_get_tree+0x8e/0x340 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount fs/namespace.c:3718 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount fs/namespace.c:4206 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:4206 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 6303: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6849 p9_client_create+0xa28/0x11d0 net/9p/client.c:1064 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663 vfs_get_tree+0x8e/0x340 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount fs/namespace.c:3718 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount fs/namespace.c:4206 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:4206 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888012dbc000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888012dbc000, ffff888012dbc200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12dbc 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: f5(slab) raw: 00fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00004b6f01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5951, tgid 5951 (syz-executor), ts 53801398882, free_ts 52308823338 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5178 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab mm/slub.c:3232 [inline] new_slab+0x24a/0x360 mm/slub.c:3286 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4655 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0x501/0x880 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3809 addrconf_f6i_alloc+0x2da/0x660 net/ipv6/route.c:4678 ipv6_add_addr+0x531/0x1fe0 net/ipv6/addrconf.c:1126 inet6_addr_add+0x256/0x960 net/ipv6/addrconf.c:3050 inet6_rtm_newaddr+0x1619/0x1c70 net/ipv6/addrconf.c:5059 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6951 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 page last free pid 111 tgid 111 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xa31/0x1610 mm/page_alloc.c:2958 shrink_folio_list+0x35c7/0x4800 mm/vmscan.c:1569 evict_folios+0x79c/0x1b30 mm/vmscan.c:4745 try_to_shrink_lruvec+0x585/0x9b0 mm/vmscan.c:4908 shrink_one+0x3e3/0x7a0 mm/vmscan.c:4953 shrink_many mm/vmscan.c:5016 [inline] lru_gen_shrink_node mm/vmscan.c:5094 [inline] shrink_node+0x26cb/0x3d80 mm/vmscan.c:6081 kswapd_shrink_node mm/vmscan.c:6941 [inline] balance_pgdat+0xbb8/0x1a50 mm/vmscan.c:7124 kswapd+0x590/0xb90 mm/vmscan.c:7389 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888012dbbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888012dbbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888012dbc000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888012dbc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888012dbc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 88 6c 24 26 mov %ch,0x26(%rsp) 4: 4c 89 7c 24 18 mov %r15,0x18(%rsp) 9: 48 c7 c7 20 ce 8b 8b mov $0xffffffff8b8bce20,%rdi 10: e8 68 ef e0 09 call 0x9e0ef7d 15: 65 66 c7 05 46 54 24 movw $0x0,%gs:0x12245446(%rip) # 0x12245465 1c: 12 00 00 1f: e8 79 7c 47 00 call 0x477c9d 24: fb sti 25: bb ff ff ff ff mov $0xffffffff,%ebx * 2a: 49 c7 c7 c0 c0 00 8e mov $0xffffffff8e00c0c0,%r15 <-- trapping instruction 31: 41 0f bc dc bsf %r12d,%ebx 35: 83 c3 01 add $0x1,%ebx 38: 0f 85 a4 00 00 00 jne 0xe2 3e: e9 .byte 0xe9 3f: b1 .byte 0xb1