================================================================== 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 ffff88804cb34418 by task syz.2.14/6070 CPU: 0 UID: 0 PID: 6070 Comm: syz.2.14 Not tainted 6.15.0-rc6-syzkaller-00105-g088d13246a46 #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+0x31e/0x400 drivers/virtio/virtio_ring.c:2690 __handle_irq_event_percpu+0x22c/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+0xe2/0x250 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:preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7090 Code: df 55 65 48 8b 2d ec c2 38 08 53 48 89 eb 48 c1 eb 03 48 01 c3 bf 01 00 00 00 e8 bf 21 1e f6 e8 4a d6 57 f6 fb bf 01 00 00 00 af 99 ff ff 9c 58 fa f6 c4 02 75 1e bf 01 00 00 00 e8 0d cc 1d RSP: 0018:ffffc90004ae7708 EFLAGS: 00000202 RAX: 0000000000009dc7 RBX: ffffed1004474488 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff8dbdccdf RDI: 0000000000000001 RBP: ffff8880223a2440 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90851f17 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:220 Code: 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c 16 00 00 85 c0 74 2b 8b 82 18 16 00 00 83 f8 02 75 20 <48> 8b 8a 20 16 00 00 8b 92 1c 16 00 00 48 8b 01 48 83 c0 01 48 39 RSP: 0018:ffffc90004ae77d8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff88806bf04f00 RCX: ffffc9000c761000 RDX: ffff8880223a2440 RSI: ffffffff8941718d RDI: ffff88805b855280 RBP: ffff88805b855280 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88805b8557f0 R14: 0000000000000000 R15: ffff888050505a00 skb_free_datagram+0xd/0x20 net/core/datagram.c:323 __unix_dgram_recvmsg+0x81d/0xee0 net/unix/af_unix.c:2505 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2522 sock_recvmsg_nosec net/socket.c:1017 [inline] ____sys_recvmsg+0x5f9/0x6b0 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: 0023:0xf711e579 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:00000000f50ed55c EFLAGS: 00000296 ORIG_RAX: 0000000000000151 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000800000c0 RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6071: 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+0x14d4/0x1f20 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 6071: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4841 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+0x14d4/0x1f20 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 ffff88804cb34400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88804cb34400, ffff88804cb34600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4cb34 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 ffffea00016e9100 dead000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801b442c80 ffffea00016e9100 dead000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 04fff00000000002 ffffea000132cd01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1135, tgid 1135 (kworker/u32:7), ts 48786679206, free_ts 48751870182 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:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] batadv_forw_packet_alloc+0x3ad/0x4e0 net/batman-adv/send.c:519 batadv_iv_ogm_aggregate_new+0x13c/0x4c0 net/batman-adv/bat_iv_ogm.c:571 batadv_iv_ogm_queue_add net/batman-adv/bat_iv_ogm.c:678 [inline] batadv_iv_ogm_schedule_buff+0x99f/0x14e0 net/batman-adv/bat_iv_ogm.c:841 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:876 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x329/0x920 net/batman-adv/bat_iv_ogm.c:1720 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 page last free pid 5989 tgid 5989 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:2716 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3185 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:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4203 vm_area_alloc+0x1f/0x160 kernel/fork.c:441 __mmap_new_vma mm/vma.c:2402 [inline] __mmap_region+0xfd0/0x27c0 mm/vma.c:2519 mmap_region+0x1ab/0x3f0 mm/vma.c:2597 do_mmap+0xd8e/0x11b0 mm/mmap.c:561 vm_mmap_pgoff+0x281/0x450 mm/util.c:579 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88804cb34300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804cb34380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804cb34400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804cb34480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804cb34500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: df 55 65 fists 0x65(%rbp) 3: 48 8b 2d ec c2 38 08 mov 0x838c2ec(%rip),%rbp # 0x838c2f6 a: 53 push %rbx b: 48 89 eb mov %rbp,%rbx e: 48 c1 eb 03 shr $0x3,%rbx 12: 48 01 c3 add %rax,%rbx 15: bf 01 00 00 00 mov $0x1,%edi 1a: e8 bf 21 1e f6 call 0xf61e21de 1f: e8 4a d6 57 f6 call 0xf657d66e 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 af 99 ff ff call 0xffff99de <-- trapping instruction 2f: 9c pushf 30: 58 pop %rax 31: fa cli 32: f6 c4 02 test $0x2,%ah 35: 75 1e jne 0x55 37: bf 01 00 00 00 mov $0x1,%edi 3c: e8 .byte 0xe8 3d: 0d .byte 0xd 3e: cc int3 3f: 1d .byte 0x1d