geom: don't write stack garbage in disk labels
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Authored by asomers on Feb 2 2018, 5:32 AM.

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des
cem

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rS328849: geom: don't write stack garbage in disk labels

Summary

geom: don't write stack garbage in disk labels

Most consumers of g_metadata_store were passing in partially unallocated
memory, resulting in stack garbage being written to disk labels. Be
more careful to only pass in the true size of the label.

gvirstor repeated the same mistake, but in the kernel.

Also, glabel's label contained a fixed-size string that wasn't
initialized to zero.

PR: 222077

Test Plan

existing geom tests

Diff Detail

Repository

rS FreeBSD src repository - subversion

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No Test Coverage

Build Status

Buildable 14735
Build 14856: arc lint + arc unit

Event Timeline

asomers created this revision.Feb 2 2018, 5:32 AM

Herald added a subscriber: imp. · View Herald TranscriptFeb 2 2018, 5:32 AM

Harbormaster completed remote builds in B14735: Diff 38772.Feb 2 2018, 5:32 AM

How sure are we that none of these routines are accessing sector past the relevant struct size? Without investigating that, I'd be more comfortable with the lesser change that just zeroed the sector arrays.