Commit f980d055a0f858d73d9467bb0b570721bbfcdfb8 causes a regression

From: Tim Gardner
Date: Mon Nov 29 2021 - 10:37:35 EST


Hi Len,

I have a report (https://bugs.launchpad.net/bugs/1952094) that commit f980d055a0f858d73d9467bb0b570721bbfcdfb8 ("CIFS: Fix a potencially linear read overflow") causes a regression as a stable backport in a 5.4 based kernel. I don't know if this regression exists in tip as well, or if it is unique to the backported environment. I suspect, given the content of the patch, that it is generic. As such, it has been backported to a number of stable releases:

linux-4.4.y.txt:0955df2d9bf4857e3e2287e3028903e6cec06c30
linux-4.9.y.txt:8878af780747f498551b7d360cae61b415798f18
linux-4.14.y.txt:20967547ffc6039f17c63a1c24eb779ee166b245
linux-4.19.y.txt:bea655491daf39f1934a71bf576bf3499092d3a4
linux-5.4.y.txt:b444064a0e0ef64491b8739a9ae05a952b5f8974
linux-5.10.y.txt:6c4857203ffa36918136756a889b12c5864bc4ad
linux-5.13.y.txt:9bffe470e9b537075345406512df01ca2188b725
linux-5.14.y.txt:c41dd61c86482ab34f6f039b13296308018fd99b

Could this be an off-by-one issue if the source string is full length ?

rtg
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Tim Gardner
Canonical, Inc