fix: enforce write permission on path-based truncate()#355
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fix: enforce write permission on path-based truncate()#355toddr-bot wants to merge 2 commits intocpan-authors:mainfrom
toddr-bot wants to merge 2 commits intocpan-authors:mainfrom
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Path-based truncate() on a read-only mocked file succeeds when it should fail with EACCES. This test proves the vulnerability before the fix. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
POSIX truncate(2) requires write permission on the file when called by path. The mocked truncate only checked permission for the filehandle form (EINVAL if not open for writing) but allowed path-based truncate to succeed on read-only files. Add _check_perms($mock, 2) for the path case. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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What
Add write permission check for path-based
truncate()on mocked files.Why
POSIX truncate(2) requires write permission on the target file. The mocked implementation only enforced this for the filehandle form (EINVAL if not open for writing) but allowed path-based truncate to silently succeed on read-only files when
set_user()was active. Fixes #354.How
Added
_check_perms($mock, 2)in theelsebranch (path-based call) of__truncate, returning EACCES on failure. This mirrors how other operations (chmod, chown) enforce permission checks. Root bypass is handled by_check_permsitself.Testing
🤖 Generated with Claude Code
Quality Report
Changes: 2 files changed, 56 insertions(+), 1 deletion(-)
Code scan: clean
Tests: failed (4 Failed, 94 test)
Branch hygiene: clean
Generated by Kōan post-mission quality pipeline