Page MenuHomeFreeBSD
Differential D52702

ng_tty: don't increment m_data
ClosedPublic
Actions

Authored by vexeduxr on Sep 23 2025, 9:38 PM.
Tags
None
Referenced Files
F146783418: D52702.id162739.diff
Thu, Mar 5, 1:53 PM
F146750418: D52702.id162739.diff
Thu, Mar 5, 7:03 AM
Unknown Object (File)
Wed, Mar 4, 3:46 PM
Unknown Object (File)
Sun, Mar 1, 1:19 PM
Unknown Object (File)
Sat, Feb 21, 8:31 AM
Unknown Object (File)
Fri, Feb 20, 9:13 PM
Unknown Object (File)
Fri, Feb 20, 9:13 PM
Unknown Object (File)
Fri, Feb 20, 5:26 PM
View All 43 Files
Subscribers
donner
melifaro

Details

Reviewers
imp
kevans
glebius
Commits
rG2dc10f2a49af: ng_tty: don't increment m_data
rGe05342f3618f: ng_tty: don't increment m_data
rGe73cc0abe140: ng_tty: don't increment m_data
rG57d5a8feda3f: ng_tty: don't increment m_data
Summary

Stop incrementing m_data so the callee can read the mbuf.

MFC after: 3 days

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Skipped
Unit
Tests Skipped
Build Status
Buildable 67269
Build 64152: arc lint + arc unit

Event Timeline

vexeduxr created this revision.Sep 23 2025, 9:38 PM
Herald added subscribers: melifaro, donner. · View Herald TranscriptSep 23 2025, 9:38 PM
vexeduxr requested review of this revision.Sep 23 2025, 9:38 PM
Harbormaster completed remote builds in B67269: Diff 162695.Sep 23 2025, 9:38 PM
kevans added inline comments.Sep 23 2025, 10:13 PM
sys/netgraph/ng_tty.c
488

That would also imply that the previous code was pretty boken, right? This appends to mbuf at m->m_len, but *mtod(m, u_char *) = c is effectively m_data[0] = c rather than m_data[m_len++] = c

kevans added inline comments.Sep 23 2025, 10:16 PM
sys/netgraph/ng_tty.c
488

Oh, I guess if it's always incrementing m_data. sorry.

vexeduxr added inline comments.Sep 24 2025, 10:22 AM
sys/netgraph/ng_tty.c
488

Doing some more digging, this used to rely on setting m_data to m_pktdat before sending it off, but that seems to have been broken since 2ffded5

glebius accepted this revision.Sep 24 2025, 11:33 AM

Thanks a lot for the fix and sorry for the breakage.

This revision is now accepted and ready to land.Sep 24 2025, 11:33 AM
vexeduxr added a comment.Sep 24 2025, 3:01 PM

No problem :)

Closed by commit rG57d5a8feda3f: ng_tty: don't increment m_data (authored by vexeduxr). · Explain WhySep 24 2025, 3:04 PM
This revision was automatically updated to reflect the committed changes.
vexeduxr added a commit: rG57d5a8feda3f: ng_tty: don't increment m_data.
vexeduxr added a commit: rGe73cc0abe140: ng_tty: don't increment m_data.Oct 1 2025, 9:39 AM
vexeduxr added a commit: rGe05342f3618f: ng_tty: don't increment m_data.
vexeduxr added a commit: rG2dc10f2a49af: ng_tty: don't increment m_data.

Revision Contents
Changeset List

PathSize
sys/
netgraph/
4 lines

Diff 162695

View Options

sys/netgraph/ng_tty.c

Loading...