================================================================== 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 ffff888067c00418 by task syz.3.601/8432 CPU: 0 UID: 0 PID: 8432 Comm: syz.3.601 Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #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:__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 b6 06 26 f6 48 89 df e8 5e 5a 26 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 55 c6 16 f6 65 8b 05 3e 74 34 08 85 c0 74 16 5b RSP: 0018:ffffc9000e0577d8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888012c48700 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff8dbe98c0 RDI: ffffffff8bf44f00 RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90866717 R11: 0000000000000001 R12: 0000000000000002 R13: ffff888012c48570 R14: ffff888012c48740 R15: ffff888012c480e8 __unix_dgram_recvmsg+0x326/0xee0 net/unix/af_unix.c:2447 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2522 sock_recvmsg_nosec net/socket.c:1017 [inline] ____sys_recvmsg+0x5f6/0x6b0 net/socket.c:2784 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2828 do_recvmmsg+0x568/0x740 net/socket.c:2915 __sys_recvmmsg+0x21c/0x280 net/socket.c:2997 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline] __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline] __ia32_compat_sys_recvmmsg_time32+0xc4/0x160 net/compat.c:414 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 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 RIP: 0023:0xf707e579 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:00000000f504d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000151 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000800000c0 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 8433: 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:3881 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4208 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount fs/namespace.c:4409 [inline] __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4409 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 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 8433: 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:2398 [inline] slab_free mm/slub.c:4656 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4855 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:3881 [inline] path_mount+0x14d4/0x1f30 fs/namespace.c:4208 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount fs/namespace.c:4409 [inline] __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4409 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 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 ffff888067c00400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888067c00400, ffff888067c00600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x67c00 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801b442c80 ffffea000177c100 dead000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801b442c80 ffffea000177c100 dead000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000002 ffffea00019f0001 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 5950, tgid 5950 (syz-executor), ts 47748939160, free_ts 47700383693 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2468 [inline] allocate_slab mm/slub.c:2632 [inline] new_slab+0x244/0x340 mm/slub.c:2686 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3872 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3962 __slab_alloc_node mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4198 [inline] __do_kmalloc_node mm/slub.c:4340 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4353 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:3802 addrconf_f6i_alloc+0x391/0x670 net/ipv6/route.c:4631 ipv6_add_addr+0x531/0x1fe0 net/ipv6/addrconf.c:1121 inet6_addr_add+0x256/0x960 net/ipv6/addrconf.c:3049 inet6_rtm_newaddr+0x1619/0x1c70 net/ipv6/addrconf.c:5060 rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x16a/0x440 net/netlink/af_netlink.c:2534 page last free pid 5957 tgid 5957 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:2725 discard_slab mm/slub.c:2730 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3199 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:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] __do_kmalloc_node mm/slub.c:4340 [inline] __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x245/0x580 security/tomoyo/file.c:723 security_file_ioctl_compat+0x9b/0x240 security/security.c:2931 __do_compat_sys_ioctl fs/ioctl.c:956 [inline] __se_compat_sys_ioctl fs/ioctl.c:947 [inline] __ia32_compat_sys_ioctl+0xc3/0x360 fs/ioctl.c:947 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 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 Memory state around the buggy address: ffff888067c00300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888067c00380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888067c00400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888067c00480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888067c00500: 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 b6 06 26 f6 call 0xf62606c9 13: 48 89 df mov %rbx,%rdi 16: e8 5e 5a 26 f6 call 0xf6265a79 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 55 c6 16 f6 call 0xf616c689 34: 65 8b 05 3e 74 34 08 mov %gs:0x834743e(%rip),%eax # 0x8347479 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx