================================================================== BUG: KASAN: slab-use-after-free in decode_session6+0x1036/0x1880 net/xfrm/xfrm_policy.c:3450 Read of size 1 at addr ffff8880588493c4 by task kworker/u4:1/11 CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.2.0-next-20230301-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319 print_report mm/kasan/report.c:430 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:536 decode_session6+0x1036/0x1880 net/xfrm/xfrm_policy.c:3450 __xfrm_decode_session+0x54/0xb0 net/xfrm/xfrm_policy.c:3556 xfrm_decode_session include/net/xfrm.h:1210 [inline] vti6_tnl_xmit+0x3e6/0x1e90 net/ipv6/ip6_vti.c:575 __netdev_start_xmit include/linux/netdevice.h:4881 [inline] netdev_start_xmit include/linux/netdevice.h:4895 [inline] xmit_one net/core/dev.c:3580 [inline] dev_hard_start_xmit+0x1c2/0x9d0 net/core/dev.c:3596 sch_direct_xmit+0x1a3/0xc30 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x4da/0x1770 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3870 [inline] __dev_queue_xmit+0x2449/0x3e80 net/core/dev.c:4212 dev_queue_xmit include/linux/netdevice.h:3051 [inline] neigh_connected_output+0x3c2/0x550 net/core/neighbour.c:1612 neigh_output include/net/neighbour.h:546 [inline] ip6_finish_output2+0x56c/0x1590 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x694/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xa63/0x1850 net/ipv6/ndisc.c:508 ndisc_send_rs+0x132/0x6f0 net/ipv6/ndisc.c:718 addrconf_rs_timer+0x3f1/0x870 net/ipv6/addrconf.c:3936 call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700 expire_timers+0x234/0x330 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x2e3/0xae3 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire.part.0+0x154/0x370 kernel/locking/lockdep.c:5634 Code: b8 ff ff ff ff 65 0f c1 05 79 4b 9c 7e 83 f8 01 0f 85 c7 01 00 00 9c 58 f6 c4 02 0f 85 da 01 00 00 48 85 ed 0f 85 ad 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc90000107a38 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff92000020f48 RCX: 18a2d0570735d906 RDX: 1ffff11002cf8896 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000200 R08: 0000000000000000 R09: ffffffff914f0c07 R10: fffffbfff229e180 R11: 1ffff11006b5f7da R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8c7979c0 rcu_lock_acquire include/linux/rcupdate.h:327 [inline] rcu_read_lock include/linux/rcupdate.h:773 [inline] inet_twsk_purge+0x132/0x900 net/ipv4/inet_timewait_sock.c:292 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 5216: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x17c/0x320 mm/slub.c:3476 getname_flags.part.0+0x50/0x4f0 fs/namei.c:140 getname_flags+0x9e/0xe0 include/linux/audit.h:321 vfs_fstatat+0x77/0xb0 fs/stat.c:275 __do_sys_newfstatat+0x8a/0x110 fs/stat.c:446 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 5216: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] kmem_cache_free+0xec/0x4e0 mm/slub.c:3809 putname fs/namei.c:272 [inline] putname+0x102/0x140 fs/namei.c:258 vfs_fstatat+0x9b/0xb0 fs/stat.c:277 __do_sys_newfstatat+0x8a/0x110 fs/stat.c:446 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888058849100 which belongs to the cache names_cache of size 4096 The buggy address is located 708 bytes inside of freed 4096-byte region [ffff888058849100, ffff88805884a100) The buggy address belongs to the physical page: page:ffffea0001621200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58848 head:ffffea0001621200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000010200 ffff888140008780 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5216, tgid 5216 (modprobe), ts 382118647343, free_ts 380184257411 prep_new_page mm/page_alloc.c:2492 [inline] get_page_from_freelist+0xf75/0x2ad0 mm/page_alloc.c:4256 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5522 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2283 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x28e/0x380 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x307/0x320 mm/slub.c:3476 getname_flags.part.0+0x50/0x4f0 fs/namei.c:140 getname_flags include/linux/audit.h:321 [inline] getname+0x92/0xd0 fs/namei.c:219 do_sys_openat2+0xf5/0x4c0 fs/open.c:1342 do_sys_open fs/open.c:1364 [inline] __do_sys_openat fs/open.c:1380 [inline] __se_sys_openat fs/open.c:1375 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1375 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_unref_page_prepare+0x4d1/0xb60 mm/page_alloc.c:3318 free_unref_page+0x33/0x370 mm/page_alloc.c:3413 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x17c/0x320 mm/slub.c:3476 getname_flags.part.0+0x50/0x4f0 fs/namei.c:140 getname_flags include/linux/audit.h:321 [inline] getname+0x92/0xd0 fs/namei.c:219 do_sys_openat2+0xf5/0x4c0 fs/open.c:1342 do_sys_open fs/open.c:1364 [inline] __do_sys_openat fs/open.c:1380 [inline] __se_sys_openat fs/open.c:1375 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1375 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888058849280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888058849300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888058849380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888058849400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888058849480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: b8 ff ff ff ff mov $0xffffffff,%eax 5: 65 0f c1 05 79 4b 9c xadd %eax,%gs:0x7e9c4b79(%rip) # 0x7e9c4b86 c: 7e d: 83 f8 01 cmp $0x1,%eax 10: 0f 85 c7 01 00 00 jne 0x1dd 16: 9c pushfq 17: 58 pop %rax 18: f6 c4 02 test $0x2,%ah 1b: 0f 85 da 01 00 00 jne 0x1fb 21: 48 85 ed test %rbp,%rbp 24: 0f 85 ad 01 00 00 jne 0x1d7 * 2a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 31: fc ff df 34: 48 01 c3 add %rax,%rbx 37: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 3e: 48 rex.W 3f: c7 .byte 0xc7