================================================================== BUG: KASAN: slab-out-of-bounds in _decode_session6+0xf56/0x1370 net/ipv6/xfrm6_policy.c:137 Read of size 1 at addr ffff8880a3779bec by task syz-executor.4/14398 CPU: 1 PID: 14398 Comm: syz-executor.4 Not tainted 4.19.204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 _decode_session6+0xf56/0x1370 net/ipv6/xfrm6_policy.c:137 __xfrm_decode_session+0x5a/0x130 net/xfrm/xfrm_policy.c:2299 xfrm_decode_session include/net/xfrm.h:1238 [inline] vti_tunnel_xmit+0x279/0x1850 net/ipv4/ip_vti.c:326 __netdev_start_xmit include/linux/netdevice.h:4345 [inline] netdev_start_xmit include/linux/netdevice.h:4359 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 sch_direct_xmit+0x2d6/0xf50 net/sched/sch_generic.c:332 qdisc_restart net/sched/sch_generic.c:395 [inline] __qdisc_run+0x4d0/0x1640 net/sched/sch_generic.c:403 __dev_xmit_skb net/core/dev.c:3500 [inline] __dev_queue_xmit+0x1518/0x2e00 net/core/dev.c:3807 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209 dst_output include/net/dst.h:455 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] ndisc_send_skb+0xa24/0x1720 net/ipv6/ndisc.c:491 ndisc_send_rs+0x131/0x690 net/ipv6/ndisc.c:685 addrconf_rs_timer+0x384/0x6a0 net/ipv6/addrconf.c:3835 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:lock_acquire+0x1ec/0x3c0 kernel/locking/lockdep.c:3911 Code: 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 b7 01 00 00 48 83 3d e9 1f a6 08 00 0f 84 2a 01 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 65 8b RSP: 0000:ffff88823584fb50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3059 RBX: ffff8880b3db0140 RCX: 1ba4b002f4f2321b RDX: dffffc0000000000 RSI: 00000000a9dc9ce7 RDI: 0000000000000282 RBP: ffffffff89f85fe0 R08: 0000000099caaf4d R09: 0000000000000001 R10: ffff8880b3db09f0 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:627 [inline] filemap_map_pages+0x130/0x11c0 mm/filemap.c:2647 do_fault_around mm/memory.c:3776 [inline] do_read_fault mm/memory.c:3810 [inline] do_fault mm/memory.c:3944 [inline] handle_pte_fault mm/memory.c:4175 [inline] __handle_mm_fault+0x2a8e/0x41c0 mm/memory.c:4299 handle_mm_fault+0x436/0xb10 mm/memory.c:4336 __do_page_fault+0x68e/0xd60 arch/x86/mm/fault.c:1412 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1205 RIP: 0033:0x464bdb Code: Bad RIP value. RSP: 002b:00007fffa66382e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000464bdb RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000001979400 R10: 00000000019796d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fffa66383d0 Allocated by task 4702: kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 getname_flags+0xce/0x590 fs/namei.c:140 user_path_at_empty+0x2a/0x50 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x113/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3137 [inline] __do_sys_newlstat fs/stat.c:350 [inline] __se_sys_newlstat+0x96/0x120 fs/stat.c:344 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4702: __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x7f/0x260 mm/slab.c:3765 putname+0xe1/0x120 fs/namei.c:261 filename_lookup+0x3d0/0x5a0 fs/namei.c:2358 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x113/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3137 [inline] __do_sys_newlstat fs/stat.c:350 [inline] __se_sys_newlstat+0x96/0x120 fs/stat.c:344 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a3778840 which belongs to the cache names_cache of size 4096 The buggy address is located 940 bytes to the right of 4096-byte region [ffff8880a3778840, ffff8880a3779840) The buggy address belongs to the page: page:ffffea00028dde00 count:1 mapcount:0 mapping:ffff88823b843380 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0001185188 ffffea000120d988 ffff88823b843380 raw: 0000000000000000 ffff8880a3778840 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a3779a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a3779b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a3779b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a3779c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a3779c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 08 00 or %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 00 48 c1 add %cl,-0x3f(%rax) 9: e8 03 80 3c 10 callq 0x103c8011 e: 00 0f add %cl,(%rdi) 10: 85 b7 01 00 00 48 test %esi,0x48000001(%rdi) 16: 83 3d e9 1f a6 08 00 cmpl $0x0,0x8a61fe9(%rip) # 0x8a62006 1d: 0f 84 2a 01 00 00 je 0x14d 23: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 28: 57 push %rdi 29: 9d popfq 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: 48 83 c4 18 add $0x18,%rsp 33: 5b pop %rbx 34: 5d pop %rbp 35: 41 5c pop %r12 37: 41 5d pop %r13 39: 41 5e pop %r14 3b: 41 5f pop %r15 3d: c3 retq 3e: 65 gs 3f: 8b .byte 0x8b