Messages in this thread | | | From | Dmitry Vyukov <> | Date | Sun, 2 Sep 2018 06:45:06 +0200 | Subject | Re: KASAN: slab-out-of-bounds Read in _decode_session6 |
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On Sun, Sep 2, 2018 at 6:41 AM, syzbot <syzbot+acffccec848dc13fe459@syzkaller.appspotmail.com> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 93ee30f3e8b4 xsk: i40e: get rid of useless struct xdp_umem.. > git tree: bpf-next > console output: https://syzkaller.appspot.com/x/log.txt?x=11f2115a400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492 > dashboard link: https://syzkaller.appspot.com/bug?extid=acffccec848dc13fe459 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=116b3492400000
Potentially this is bpf-related because the repro just runs a bpf program. +bpf maintainers.
> IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+acffccec848dc13fe459@syzkaller.appspotmail.com > > 8021q: adding VLAN 0 to HW filter on device team0 > 8021q: adding VLAN 0 to HW filter on device team0 > 8021q: adding VLAN 0 to HW filter on device team0 > 8021q: adding VLAN 0 to HW filter on device team0 > ================================================================== > BUG: KASAN: slab-out-of-bounds in _decode_session6+0x1331/0x14e0 > net/ipv6/xfrm6_policy.c:161 > Read of size 1 at addr ffff8801d882eec7 by task syz-executor1/6667 > > CPU: 0 PID: 6667 Comm: syz-executor1 Not tainted 4.19.0-rc1+ #86 > 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+0x1c9/0x2b4 lib/dump_stack.c:113 > print_address_description+0x6c/0x20b mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 > __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 > _decode_session6+0x1331/0x14e0 net/ipv6/xfrm6_policy.c:161 > __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2299 > xfrm_decode_session include/net/xfrm.h:1232 [inline] > vti6_tnl_xmit+0x3c3/0x1bc1 net/ipv6/ip6_vti.c:542 > __netdev_start_xmit include/linux/netdevice.h:4313 [inline] > netdev_start_xmit include/linux/netdevice.h:4322 [inline] > xmit_one net/core/dev.c:3217 [inline] > dev_hard_start_xmit+0x272/0xc10 net/core/dev.c:3233 > __dev_queue_xmit+0x2ab2/0x3870 net/core/dev.c:3803 > dev_queue_xmit+0x17/0x20 net/core/dev.c:3836 > __bpf_tx_skb net/core/filter.c:2012 [inline] > __bpf_redirect_common net/core/filter.c:2050 [inline] > __bpf_redirect+0x5b7/0xae0 net/core/filter.c:2057 > ____bpf_clone_redirect net/core/filter.c:2090 [inline] > bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2062 > bpf_prog_c39d1ba309a769f7+0x749/0x1000 > > Allocated by task 6667: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 > __do_kmalloc_node mm/slab.c:3682 [inline] > __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3696 > __kmalloc_reserve.isra.41+0x3a/0xe0 net/core/skbuff.c:137 > pskb_expand_head+0x230/0x10e0 net/core/skbuff.c:1463 > skb_ensure_writable+0x3dd/0x640 net/core/skbuff.c:5129 > __bpf_try_make_writable net/core/filter.c:1633 [inline] > bpf_try_make_writable net/core/filter.c:1639 [inline] > bpf_try_make_head_writable net/core/filter.c:1647 [inline] > ____bpf_clone_redirect net/core/filter.c:2084 [inline] > bpf_clone_redirect+0x14a/0x490 net/core/filter.c:2062 > bpf_prog_c39d1ba309a769f7+0x749/0x1000 > > Freed by task 5493: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xd9/0x210 mm/slab.c:3813 > skb_free_head+0x99/0xc0 net/core/skbuff.c:550 > skb_release_data+0x6a4/0x880 net/core/skbuff.c:570 > skb_release_all+0x4a/0x60 net/core/skbuff.c:627 > __kfree_skb net/core/skbuff.c:641 [inline] > consume_skb+0x190/0x4e0 net/core/skbuff.c:701 > netlink_dump+0xb14/0xd50 net/netlink/af_netlink.c:2269 > netlink_recvmsg+0xf84/0x1490 net/netlink/af_netlink.c:1991 > sock_recvmsg_nosec net/socket.c:794 [inline] > sock_recvmsg+0xd0/0x110 net/socket.c:801 > ___sys_recvmsg+0x2b6/0x680 net/socket.c:2276 > __sys_recvmsg+0x11a/0x290 net/socket.c:2325 > __do_sys_recvmsg net/socket.c:2335 [inline] > __se_sys_recvmsg net/socket.c:2332 [inline] > __x64_sys_recvmsg+0x78/0xb0 net/socket.c:2332 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801d882ecc0 > which belongs to the cache kmalloc-512 of size 512 > The buggy address is located 7 bytes to the right of > 512-byte region [ffff8801d882ecc0, ffff8801d882eec0) > The buggy address belongs to the page: > page:ffffea0007620b80 count:1 mapcount:0 mapping:ffff8801dac00940 index:0x0 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffffea00070fc048 ffffea00075f9c08 ffff8801dac00940 > raw: 0000000000000000 ffff8801d882e040 0000000100000006 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d882ed80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff8801d882ee00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >> >> ffff8801d882ee80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc > > ^ > ffff8801d882ef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d882ef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/0000000000003658b00574dc08cc%40google.com. > For more options, visit https://groups.google.com/d/optout.
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