================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5091 Read of size 8 at addr ffff8880306bdc18 by task syz-executor/5961 CPU: 3 UID: 0 PID: 5961 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 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+0xd9/0x110 mm/kasan/report.c:634 __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5091 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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+0x1e7/0x2f0 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:249 [inline] call_irq_handler arch/x86/kernel/irq.c:261 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:287 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:280 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 96 dc 3c f6 48 89 df e8 ee 5b 3d f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 65 31 2e f6 65 8b 05 a6 13 aa 74 85 c0 74 16 5b RSP: 0018:ffffc900034ffbd8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff8880325dd290 RCX: 1ffffffff20c4311 RDX: 0000000000000000 RSI: ffffffff8b6cee00 RDI: ffffffff8bd35aa0 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625c17 R11: 0000000000000002 R12: 1ffff9200069ff84 R13: ffff8880325dc880 R14: ffff8880325dcb30 R15: ffffffff8daa2d98 task_rq_unlock kernel/sched/sched.h:1827 [inline] wake_up_new_task+0x87f/0xd40 kernel/sched/core.c:4893 kernel_clone+0x59b/0x960 kernel/fork.c:2846 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4923839d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc74dbf4c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff4923839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055555edf17d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000021971 R15: 00007ffc74dbf660 Allocated by task 7159: 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:901 [inline] p9_client_create+0xc8/0x1200 net/9p/client.c:985 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x14e6/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7159: 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:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 p9_client_create+0xa58/0x1200 net/9p/client.c:1064 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa30 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x14e6/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880306bdc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff8880306bdc00, ffff8880306bde00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x306bc 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 ffff88801b042c80 ffffea0001389400 dead000000000002 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042c80 ffffea0001389400 dead000000000002 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000c1af01 ffffffffffffffff 0000000000000000 head: 0000000000000004 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 5959, tgid 5959 (syz-executor), ts 97074830682, free_ts 96621233978 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x2ec/0x510 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1910 net/ipv6/route.c:3766 ip6_route_add+0x26/0x1c0 net/ipv6/route.c:3858 addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2549 addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2567 inet6_addr_add+0xfb/0x950 net/ipv6/addrconf.c:3029 inet6_rtm_newaddr+0x1444/0x19d0 net/ipv6/addrconf.c:5054 rtnetlink_rcv_msg+0x95b/0xea0 net/core/rtnetlink.c:6912 page last free pid 5992 tgid 5992 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 __put_partials+0x14c/0x170 mm/slub.c:3153 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:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x1cd/0x510 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_realpath_from_path+0xb9/0x720 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:822 security_inode_getattr+0x116/0x290 security/security.c:2377 vfs_getattr fs/stat.c:243 [inline] vfs_fstat+0x4b/0xd0 fs/stat.c:265 vfs_fstatat+0xbc/0xf0 fs/stat.c:366 __do_sys_newfstatat+0xa2/0x130 fs/stat.c:532 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880306bdb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880306bdb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880306bdc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880306bdc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880306bdd00: 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 96 dc 3c f6 call 0xf63cdca9 13: 48 89 df mov %rbx,%rdi 16: e8 ee 5b 3d f6 call 0xf63d5c09 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 65 31 2e f6 call 0xf62e3199 34: 65 8b 05 a6 13 aa 74 mov %gs:0x74aa13a6(%rip),%eax # 0x74aa13e1 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx