================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2dd6/0x3b30 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff88801b3f2418 by task syz-executor.2/5284 CPU: 0 PID: 5284 Comm: syz-executor.2 Not tainted 6.9.0-rc5-syzkaller-00355-g2c8159388952 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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+0x2dd6/0x3b30 kernel/locking/lockdep.c:5005 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:394 [inline] p9_req_put net/9p/client.c:402 [inline] p9_req_put+0xca/0x250 net/9p/client.c:399 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:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0xde/0x250 arch/x86/kernel/irq.c:257 common_interrupt+0xab/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x24/0xc0 kernel/rcu/tree.c:700 Code: 90 90 90 90 90 90 f3 0f 1e fa 55 53 65 ff 05 0b dc 8e 7e e8 8e df 5d 09 48 c7 c3 e8 7e 03 00 83 f8 07 89 c5 0f 87 82 00 00 00 <48> 8d 3c ed 40 6b 22 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 RSP: 0018:ffffc90002e278a0 EFLAGS: 00000297 RAX: 0000000000000000 RBX: 0000000000037ee8 RCX: ffffc9000d194000 RDX: 0000000000000001 RSI: ffffffff8b6f1320 RDI: ffffffff8b6f1360 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000002 R12: ffff88805425e3c0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 xa_entry include/linux/xarray.h:1216 [inline] xas_descend+0x2d9/0x4f0 lib/xarray.c:206 xas_load+0xe4/0x140 lib/xarray.c:244 filemap_get_entry+0x10f/0x470 mm/filemap.c:1816 shmem_get_folio_gfp+0x369/0x13e0 mm/shmem.c:1982 shmem_get_folio mm/shmem.c:2160 [inline] shmem_write_begin+0x15a/0x370 mm/shmem.c:2744 generic_perform_write+0x272/0x620 mm/filemap.c:3974 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2920 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 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 RIP: 0023:0xf7349579 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:00000000f5f3b3b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000edb1b000 RDX: 0000000001000000 RSI: 00000000f74a0ff4 RDI: 0000000000000000 RBP: 00000000f5f3b460 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 5293: 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 include/linux/slab.h:628 [inline] p9_client_create+0xcf/0x11b0 net/9p/client.c:980 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xaa0 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1779 do_new_mount fs/namespace.c:3352 [inline] path_mount+0x6e1/0x1f10 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount fs/namespace.c:3875 [inline] __ia32_sys_mount+0x295/0x320 fs/namespace.c:3875 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 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 5293: 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 mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x390 mm/slub.c:4390 p9_client_create+0x9ca/0x11b0 net/9p/client.c:1051 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xaa0 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1779 do_new_mount fs/namespace.c:3352 [inline] path_mount+0x6e1/0x1f10 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount fs/namespace.c:3875 [inline] __ia32_sys_mount+0x295/0x320 fs/namespace.c:3875 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 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 ffff88801b3f2400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88801b3f2400, ffff88801b3f2600) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b3f0 head: order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000840 ffff888014c42c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 head: 00fff80000000840 ffff888014c42c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 head: 00fff80000000002 ffffea00006cfc01 ffffea00006cfc48 00000000ffffffff head: 0000000400000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5219, tgid -2087953315 (syz-executor.2), ts 5219, free_ts 58008717167 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2391 ___slab_alloc+0x670/0x16d0 mm/slub.c:3525 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610 __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc+0x3b4/0x440 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1ae0 net/ipv6/route.c:3759 addrconf_f6i_alloc+0x393/0x670 net/ipv6/route.c:4583 ipv6_add_addr+0x538/0x2090 net/ipv6/addrconf.c:1119 inet6_addr_add+0x3bb/0xbe0 net/ipv6/addrconf.c:3058 inet6_rtm_newaddr+0x11ea/0x1ac0 net/ipv6/addrconf.c:5046 rtnetlink_rcv_msg+0x3c7/0xe60 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2559 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x542/0x820 net/netlink/af_netlink.c:1361 page last free pid 5261 tgid 5261 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487 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:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3852 proc_reg_open+0x21d/0x610 fs/proc/inode.c:517 do_dentry_open+0x8da/0x18c0 fs/open.c:955 do_open fs/namei.c:3642 [inline] path_openat+0x1dfb/0x2990 fs/namei.c:3799 do_filp_open+0x1dc/0x430 fs/namei.c:3826 do_sys_openat2+0x17a/0x1e0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88801b3f2300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801b3f2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801b3f2400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b3f2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b3f2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: f3 0f 1e fa endbr64 a: 55 push %rbp b: 53 push %rbx c: 65 ff 05 0b dc 8e 7e incl %gs:0x7e8edc0b(%rip) # 0x7e8edc1e 13: e8 8e df 5d 09 call 0x95ddfa6 18: 48 c7 c3 e8 7e 03 00 mov $0x37ee8,%rbx 1f: 83 f8 07 cmp $0x7,%eax 22: 89 c5 mov %eax,%ebp 24: 0f 87 82 00 00 00 ja 0xac * 2a: 48 8d 3c ed 40 6b 22 lea -0x72dd94c0(,%rbp,8),%rdi <-- trapping instruction 31: 8d 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 48 89 fa mov %rdi,%rdx 3f: 48 rex.W