Date: Wed, 11 Feb 2026 06:15:36 +0000 From: Colin Percival <cperciva@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Cc: Dag-Erling=?utf-8?Q? Sm=C3=B8rg?=rav <des@FreeBSD.org> Subject: git: 6761e555376e - releng/14.4 - diff: Fix pagination leak Message-ID: <698c1e88.34a1d.245c14d2@gitrepo.freebsd.org>
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The branch releng/14.4 has been updated by cperciva: URL: https://cgit.FreeBSD.org/src/commit/?id=6761e555376e375f89fe36c72f2813f5e64a7f63 commit 6761e555376e375f89fe36c72f2813f5e64a7f63 Author: Dag-Erling Smørgrav <des@FreeBSD.org> AuthorDate: 2026-02-05 14:39:53 +0000 Commit: Colin Percival <cperciva@FreeBSD.org> CommitDate: 2026-02-11 06:14:26 +0000 diff: Fix pagination leak * Drop an unnecessary variable and rename pidfd to procd. * Rewinding stdout serves no purpose, so stop doing it. * Don't bother freeing memory or setting the global status right before erroring out. * Error out if dup(2) or dup2(2) fail. * In the unlikely case that our pipe is equal to stdout, we need to record that information so we don't close it when cleaning up. * Don't bother closing a descriptor before dup2(2)ing to it. * Don't forget to close the the process descriptor after reaping the child process. Approved by: re (cperciva) PR: 266592 MFC after: 1 week Sponsored by: Klara, Inc. Reviewed by: kevans, markj Differential Revision: https://reviews.freebsd.org/D55112 (cherry picked from commit c3904a7de78ca1ca15fcdf4c09f9d4be7f6fe6f5) (cherry picked from commit 144455c333dc0d3db369596038de2e3dd6113b46) --- usr.bin/diff/pr.c | 22 ++++++++++------------ usr.bin/diff/pr.h | 1 + usr.bin/diff/tests/diff_test.sh | 1 - 3 files changed, 11 insertions(+), 13 deletions(-) diff --git a/usr.bin/diff/pr.c b/usr.bin/diff/pr.c index 5dedf689351c..20869e494d4a 100644 --- a/usr.bin/diff/pr.c +++ b/usr.bin/diff/pr.c @@ -45,7 +45,6 @@ struct pr * start_pr(char *file1, char *file2) { int pfd[2]; - int pr_pd; pid_t pid; char *header; struct pr *pr; @@ -55,13 +54,10 @@ start_pr(char *file1, char *file2) xasprintf(&header, "%s %s %s", diffargs, file1, file2); signal(SIGPIPE, SIG_IGN); fflush(stdout); - rewind(stdout); if (pipe(pfd) == -1) err(2, "pipe"); - switch ((pid = pdfork(&pr_pd, PD_CLOEXEC))) { + switch ((pid = pdfork(&pr->procd, PD_CLOEXEC))) { case -1: - status |= 2; - free(header); err(2, "No more processes"); case 0: /* child */ @@ -73,21 +69,23 @@ start_pr(char *file1, char *file2) execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0); _exit(127); default: - /* parent */ - if (pfd[1] != STDOUT_FILENO) { - pr->ostdout = dup(STDOUT_FILENO); - dup2(pfd[1], STDOUT_FILENO); + if (pfd[1] == STDOUT_FILENO) { + pr->ostdout = STDOUT_FILENO; + } else { + if ((pr->ostdout = dup(STDOUT_FILENO)) < 0 || + dup2(pfd[1], STDOUT_FILENO) < 0) { + err(2, "stdout"); + } close(pfd[1]); } close(pfd[0]); - rewind(stdout); free(header); pr->kq = kqueue(); if (pr->kq == -1) err(2, "kqueue"); pr->e = xmalloc(sizeof(struct kevent)); - EV_SET(pr->e, pr_pd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, + EV_SET(pr->e, pr->procd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL); if (kevent(pr->kq, pr->e, 1, NULL, 0, NULL) == -1) err(2, "kevent"); @@ -106,7 +104,6 @@ stop_pr(struct pr *pr) fflush(stdout); if (pr->ostdout != STDOUT_FILENO) { - close(STDOUT_FILENO); dup2(pr->ostdout, STDOUT_FILENO); close(pr->ostdout); } @@ -114,6 +111,7 @@ stop_pr(struct pr *pr) err(2, "kevent"); wstatus = pr->e[0].data; close(pr->kq); + close(pr->procd); free(pr); if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0) errx(2, "pr exited abnormally"); diff --git a/usr.bin/diff/pr.h b/usr.bin/diff/pr.h index 2ff5949f282f..0a1275cfeab5 100644 --- a/usr.bin/diff/pr.h +++ b/usr.bin/diff/pr.h @@ -28,6 +28,7 @@ struct pr { int ostdout; + int procd; int kq; struct kevent *e; }; diff --git a/usr.bin/diff/tests/diff_test.sh b/usr.bin/diff/tests/diff_test.sh index 2a07535d3d86..b499bb709cdd 100755 --- a/usr.bin/diff/tests/diff_test.sh +++ b/usr.bin/diff/tests/diff_test.sh @@ -421,7 +421,6 @@ prleak_body() ulimit -n 1000 ulimit -u 1000 atf_check diff -rul a b - atf_check diff -Astone -rul a b } atf_init_test_cases()home | help
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