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Date:      Wed, 22 Feb 2017 05:43:28 +0000
From:      bugzilla-noreply@freebsd.org
To:        freebsd-bugs@FreeBSD.org
Subject:   [Bug 217287] if_em: "Off by 8" error in network streams under -CURRENT as of roughly Feb 1
Message-ID:  <bug-217287-8@https.bugs.freebsd.org/bugzilla/>

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D217287

            Bug ID: 217287
           Summary: if_em: "Off by 8" error in network streams under
                    -CURRENT as of roughly Feb 1
           Product: Base System
           Version: CURRENT
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: freebsd-bugs@FreeBSD.org
          Reporter: jeff@baitis.net

Originally discovered in TrueOS UNSTABLE and tested / verified in vanilla
FreeBSD kernel source as of 12.0-CURRENT FreeBSD 12.0-CURRENT #1
7a0e1ff53(master) -- originally recorded at
https://github.com/trueos/trueos-core/issues/327

Summary:

Corruption observed in network data within socket stream resulting in chang=
es
of a +8 value added, at seemingly random intervals, to bytes within the str=
eam

Hardware:

  CPU: Intel(R) Xeon(R) CPU E3-1225 v3 @ 3.20GHz

  Selected data from `lspci -v`:
    00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v3 Processor DRAM
Controller (rev 06)
    00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217=
-LM
(rev 04)
    00:1f.0 ISA bridge: Intel Corporation C226 Series Chipset Family Server
Advanced SKU LPC Controller (rev 04)
    00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SM=
Bus
Controller (rev 04)
    01:00.0 VGA compatible controller: NVIDIA Corporation GK208 [GeForce GT
730] (rev a1)

Steps to reproduce:

$ curl http://norvig.com/big.txt -o big.txt
$ curl http://norvig.com/big.txt -o big2.txt
$ sha256 big.txt=20
SHA256 (big.txt) =3D
a36fe438864ad8c7b76ca310c2d1176689bbf79536f84338ebd3dc253997efd5
$ sha256 big2.txt=20
SHA256 (big2.txt) =3D
71f0fa4bf8585feae457dbfc0b48dd6dfef8dcd03a07220a5754e0876b9e4efc

`diff -u big.txt big2.txt` results in lines such as:

-There was a movement and an mxclamation from my right, and peering through=
 the
gloom, I saw Whitney, pale, haggard, and unkempt, staring out at me.
+There was a movement and an exclamation from my right, and peering through=
 the
gloom, I saw Whitney, pale, haggard, and unkempt, staring out at me.=20=20=
=20


-" 'You may as well face the matter,' said I; 'you have been caught in the =
act,
and no confession could make your guilt more heinous. If you but make such
reparation as is in your power, by telling us where the beryls are, all sha=
ll
be forgiven and forgotten.'
+" 'You may as well face the matter,' said I; 'you have been caught in the =
act,
and no confession could make your guilt more heino}s. If you but make such
reparation as is in your power, by telling us where the beryls are, all sha=
ll
be forgiven and forgotten.'

Diagnostic:

+>>> ord('m') - ord('e')
8
+>>> ord('}') - ord('u')
8

Last working state:

The last working version in -CURRENT occurs somewhere prior to commit=20
'8f3781173d79d5b83e19f59b10b54263976dd66e' which was merged into the TrueOS
"drm-next" branch on Jan 27.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



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