================================================================== BUG: KASAN: use-after-free in decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 Read of size 1 at addr ffff888041bd94d7 by task syz-executor.4/20640 CPU: 1 PID: 20640 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3456 xfrm_decode_session include/net/xfrm.h:1149 [inline] vti_tunnel_xmit+0x26d/0x1b80 net/ipv4/ip_vti.c:294 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606 sch_direct_xmit+0x19f/0xbc0 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x4bc/0x1700 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3875 [inline] __dev_queue_xmit+0x2091/0x3630 net/core/dev.c:4194 neigh_connected_output+0x3b6/0x510 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:527 [inline] ip6_finish_output2+0x571/0x14e0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x4c1/0x1050 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3898 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7f0ac90a29da Code: 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e 48 8b 3e <48> 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73 47 49 89 RSP: 002b:00007ffd4c37bed0 EFLAGS: 00000293 RAX: 00007f0ac8dd5970 RBX: 00007f0ac8c6c048 RCX: ffffffff819bf6bd RDX: ffffffff817e00a0 RSI: 00007f0ac8c6c050 RDI: ffffffff817e00d1 RBP: 00007f0ac8c6c018 R08: 00007f0ac8dd59a0 R09: 0000001b30628fe0 R10: 0000000000000b17 R11: 00000000f5904b1b R12: 00007f0ac8c6c010 R13: 00007f0ac8c6c048 R14: 00007f0ac8c6c008 R15: 000000000000001f Allocated by task 20089: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x83/0xb0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3213 [inline] slab_alloc mm/slub.c:3221 [inline] kmem_cache_alloc+0x209/0x390 mm/slub.c:3226 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2800 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x142/0x390 fs/stat.c:221 vfs_fstatat fs/stat.c:243 [inline] vfs_lstat include/linux/fs.h:3356 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:398 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 20089: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1726 slab_free mm/slub.c:3492 [inline] kmem_cache_free+0x95/0x5d0 mm/slub.c:3508 putname fs/namei.c:270 [inline] putname+0xfe/0x140 fs/namei.c:256 user_path_at_empty+0x4d/0x60 fs/namei.c:2803 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x142/0x390 fs/stat.c:221 vfs_fstatat fs/stat.c:243 [inline] vfs_lstat include/linux/fs.h:3356 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:398 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888041bd9100 which belongs to the cache names_cache of size 4096 The buggy address is located 983 bytes inside of 4096-byte region [ffff888041bd9100, ffff888041bda100) The buggy address belongs to the page: page:ffffea000106f600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x41bd8 head:ffffea000106f600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010dc63c0 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 20089, ts 1038547909912, free_ts 1038525947753 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4155 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5381 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1770 [inline] allocate_slab mm/slub.c:1907 [inline] new_slab+0x319/0x490 mm/slub.c:1970 ___slab_alloc+0x921/0xfe0 mm/slub.c:3001 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3088 slab_alloc_node mm/slub.c:3179 [inline] slab_alloc mm/slub.c:3221 [inline] kmem_cache_alloc+0x363/0x390 mm/slub.c:3226 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:323 user_path_at_empty+0x2b/0x60 fs/namei.c:2800 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x142/0x390 fs/stat.c:221 vfs_fstatat fs/stat.c:243 [inline] vfs_lstat include/linux/fs.h:3356 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:398 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare+0x326/0x810 mm/page_alloc.c:1391 free_unref_page_prepare mm/page_alloc.c:3317 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3396 kvfree+0x42/0x50 mm/util.c:620 device_release+0x9f/0x240 drivers/base/core.c:2230 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 netdev_run_todo+0x75a/0xa80 net/core/dev.c:10635 default_device_exit_batch+0x2ff/0x3c0 net/core/dev.c:11605 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888041bd9380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888041bd9400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888041bd9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888041bd9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888041bd9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================