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Differential D16853

tftpd: Fix data corruption bug with netascii
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Authored by asomers on Aug 22 2018, 10:30 PM.
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cem
imp
Commits
rS339062: MFC r338216:
rS339057: MFC r338216:
rS338216: tftpd: Fix data corruption bug with netascii
Summary

tftpd: Fix data corruption bug with netascii

Transferring files in netascii format requires, among other things, translating
all CR characters to a CR,NUL pair. tftpd does this correctly except when the
CR occurs as the last octet of a packet. In that case, it erroneously drops
the NUL which should be part of the following packet. The bug was caused by
using 0 as a sentinel value in a variable that could legitimately hold 0. Fix
it by switching the sentinel value to -1.

PR: 178055

Test Plan

Manually tested with the example file from the PR.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Event Timeline

asomers created this revision.Aug 22 2018, 10:30 PM
Harbormaster completed remote builds in B19069: Diff 47134.Aug 22 2018, 10:30 PM
cem added inline comments.Aug 22 2018, 11:01 PM
libexec/tftpd/tftp-file.c
162–167 ↗(On Diff #47134)

Is buffer sized such that this does not overflow?

164 ↗(On Diff #47134)

typo -- alllowed

asomers marked 2 inline comments as done.Aug 22 2018, 11:04 PM
asomers added inline comments.
libexec/tftpd/tftp-file.c
162–167 ↗(On Diff #47134)

Yes. The buffer is fixed at the maximum segment size + 4 (in tftpd-utils.h). count will never be greater than the maximum segment size.

164 ↗(On Diff #47134)

I"ll fix.

asomers updated this revision to Diff 47140.Aug 22 2018, 11:04 PM
asomers marked 2 inline comments as done.

Fix an old typo in a comment

Harbormaster completed remote builds in B19074: Diff 47140.Aug 22 2018, 11:04 PM
cem accepted this revision.Aug 22 2018, 11:23 PM

Perfect, thanks!

This revision is now accepted and ready to land.Aug 22 2018, 11:23 PM
asomers added a comment.Aug 22 2018, 11:28 PM

Thanks @cem. I know I can always count on you for a good review.

Closed by commit rS338216: tftpd: Fix data corruption bug with netascii (authored by asomers). · Explain WhyAug 22 2018, 11:31 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathSize
head/
libexec/
tftpd/
10 lines

Diff 47142

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head/libexec/tftpd/tftp-file.c

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