================================================================== 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 ffff888024679818 by task swapper/3/0 CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.15.0-rc1-syzkaller-00065-g3b07108ada81 #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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:557 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire kernel/locking/lockdep.c:5840 [inline] lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5823 __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:2715 [inline] vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2690 __handle_irq_event_percpu+0x229/0x7d0 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:254 [inline] call_irq_handler arch/x86/kernel/irq.c:266 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:292 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 Code: 95 5d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 bc 17 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 00000286 RAX: 0000000000043421 RBX: 0000000000000003 RCX: ffffffff8b723439 RDX: 0000000000000000 RSI: ffffffff8dbeef8e RDI: ffffffff8bf465c0 RBP: ffffed1003bd3000 R08: 0000000000000001 R09: ffffed100d4e65bd R10: ffff88806a732deb R11: 0000000000000000 R12: 0000000000000003 R13: ffff88801de98000 R14: ffffffff90865310 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 Allocated by task 6136: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] p9_client_create+0xc7/0x11c0 net/9p/client.c:985 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1759 do_new_mount fs/namespace.c:3879 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4206 do_mount fs/namespace.c:4219 [inline] __do_sys_mount fs/namespace.c:4430 [inline] __se_sys_mount fs/namespace.c:4407 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4407 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6136: 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:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4845 p9_client_create+0xa28/0x11c0 net/9p/client.c:1064 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc5/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1759 do_new_mount fs/namespace.c:3879 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4206 do_mount fs/namespace.c:4219 [inline] __do_sys_mount fs/namespace.c:4430 [inline] __se_sys_mount fs/namespace.c:4407 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4407 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888024679800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888024679800, ffff888024679a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24678 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b442c80 ffffea0000ab0700 0000000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442c80 ffffea0000ab0700 0000000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000919e01 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 46, tgid 46 (kworker/u32:2), ts 95404725445, free_ts 95221513519 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1717 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x1193/0x39b0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4934 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2459 [inline] allocate_slab mm/slub.c:2623 [inline] new_slab+0x23c/0x330 mm/slub.c:2676 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3862 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3952 __slab_alloc_node mm/slub.c:4027 [inline] slab_alloc_node mm/slub.c:4188 [inline] __do_kmalloc_node mm/slub.c:4330 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4343 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x33f/0x18e0 net/ipv6/route.c:3801 ip6_route_add+0x26/0x1c0 net/ipv6/route.c:3895 addrconf_add_mroute+0x1dd/0x350 net/ipv6/addrconf.c:2551 addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2569 addrconf_dev_config net/ipv6/addrconf.c:3479 [inline] addrconf_init_auto_addrs+0x380/0x820 net/ipv6/addrconf.c:3567 addrconf_notify+0x6e2/0x19e0 net/ipv6/addrconf.c:3740 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 page last free pid 5362 tgid 5362 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2680 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4151 [inline] slab_alloc_node mm/slub.c:4200 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4252 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658 alloc_skb include/linux/skbuff.h:1340 [inline] netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1187 netlink_sendmsg+0x6a1/0xdd0 net/netlink/af_netlink.c:1858 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888024679700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888024679780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888024679800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888024679880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024679900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 95 xchg %eax,%ebp 1: 5d pop %rbp 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d d3 bc 17 00 verw 0x17bcd3(%rip) # 0x17bcfb 28: fb sti 29: f4 hlt * 2a: c3 ret <-- trapping instruction 2b: cc int3 2c: cc int3 2d: cc int3 2e: cc int3 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop