Page MenuHomeFreeBSD

14.5/errata.adoc: read(2)/write(2) integer overflow issue
Needs ReviewPublic

Authored by vladlen on Sat, Sep 5, 12:47 PM.
Referenced Files
F174597812: D59441.diff
Sun, Oct 4, 1:39 PM
Unknown Object (File)
Sat, Oct 3, 6:00 AM
Unknown Object (File)
Fri, Oct 2, 11:41 AM
Unknown Object (File)
Wed, Sep 30, 7:53 PM
Unknown Object (File)
Wed, Sep 30, 11:17 AM
Unknown Object (File)
Tue, Sep 29, 3:55 PM
Unknown Object (File)
Mon, Sep 28, 1:50 PM
Unknown Object (File)
Sat, Sep 26, 6:42 PM
Subscribers
None

Details

Reviewers
des
ziaee
cperciva
Group Reviewers
releng
Summary

Description:
This change adds an Open Issues entry to errata.adoc for FreeBSD 14.5-RELEASE
regarding a bug where read(2) and write(2) may return more bytes than requested
when operating on buffers of 2 GiB or larger. This occurs due to an integer overflow
in the I/O fault-handling path.

Impact:
Applications that perform large single I/O operations
(e.g., borgbackup reading its repository index) may receive incorrect return values,
leading to application errors. Data integrity is not affected.

Workaround:
sysctl debug.vn_io_fault_enable=0 disables the problematic path.

Status: The issue will be addressed in a future patch-level update.

PR: 298159

Please review and confirm. Please pay special attention
to the workaround — it was taken from the bug report description,
but I am not 100% sure it is a complete or reliable workaround for all cases.
If it is not, we may need to rephrase or remove it.

Diff Detail

Repository
R9 FreeBSD doc repository
Lint
Lint Skipped
Unit
Tests Skipped

Event Timeline

vladlen created this revision.