Date: Thu, 05 Feb 2026 15:27:23 +0000 From: Dag-Erling=?utf-8?Q? Sm=C3=B8rg?=rav <des@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: e8009e02e967 - stable/14 - diff: Detect loops when diffing directories. Message-ID: <6984b6db.3fc7b.6a40e336@gitrepo.freebsd.org>
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The branch stable/14 has been updated by des: URL: https://cgit.FreeBSD.org/src/commit/?id=e8009e02e967618c58a033ace838561ba3400d38 commit e8009e02e967618c58a033ace838561ba3400d38 Author: Dag-Erling Smørgrav <des@FreeBSD.org> AuthorDate: 2025-06-20 11:10:35 +0000 Commit: Dag-Erling Smørgrav <des@FreeBSD.org> CommitDate: 2026-02-05 14:47:46 +0000 diff: Detect loops when diffing directories. Sponsored by: Klara, Inc. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D50936 (cherry picked from commit 42092e1b6625b8226de5f34d22b9a96c713626cb) --- usr.bin/diff/diffdir.c | 85 ++++++++++++++++++++++++++++++++++++----- usr.bin/diff/tests/diff_test.sh | 17 +++++++++ 2 files changed, 92 insertions(+), 10 deletions(-) diff --git a/usr.bin/diff/diffdir.c b/usr.bin/diff/diffdir.c index 798229e990df..08c2efd119ca 100644 --- a/usr.bin/diff/diffdir.c +++ b/usr.bin/diff/diffdir.c @@ -22,10 +22,12 @@ #include <sys/cdefs.h> #include <sys/stat.h> +#include <sys/tree.h> #include <dirent.h> #include <err.h> #include <errno.h> +#include <fcntl.h> #include <fnmatch.h> #include <stdio.h> #include <stdlib.h> @@ -42,6 +44,61 @@ static void print_only(const char *, size_t, const char *); #define d_status d_type /* we need to store status for -l */ +struct inode { + dev_t dev; + ino_t ino; + RB_ENTRY(inode) entry; +}; + +static int +inodecmp(struct inode *a, struct inode *b) +{ + return (a->dev < b->dev ? -1 : a->dev > b->dev ? 1 : + a->ino < b->ino ? -1 : a->ino > b->ino ? 1 : 0); +} + +RB_HEAD(inodetree, inode); +static struct inodetree v1 = RB_INITIALIZER(&v1); +static struct inodetree v2 = RB_INITIALIZER(&v2); +RB_GENERATE_STATIC(inodetree, inode, entry, inodecmp); + +static int +vscandir(struct inodetree *tree, const char *path, struct dirent ***dirp, + int (*select)(const struct dirent *), + int (*compar)(const struct dirent **, const struct dirent **)) +{ + struct stat sb; + struct inode *ino = NULL; + int fd = -1, ret, serrno; + + if ((fd = open(path, O_DIRECTORY | O_RDONLY)) < 0 || + (ino = calloc(1, sizeof(*ino))) == NULL || + fstat(fd, &sb) != 0) + goto fail; + ino->dev = sb.st_dev; + ino->ino = sb.st_ino; + if (RB_FIND(inodetree, tree, ino)) { + free(ino); + close(fd); + warnx("%s: Directory loop detected", path); + *dirp = NULL; + return (0); + } + if ((ret = fscandir(fd, dirp, select, compar)) < 0) + goto fail; + RB_INSERT(inodetree, tree, ino); + close(fd); + return (ret); +fail: + serrno = errno; + if (ino != NULL) + free(ino); + if (fd >= 0) + close(fd); + errno = serrno; + return (-1); +} + /* * Diff directory traversal. Will be called recursively if -r was specified. */ @@ -62,26 +119,22 @@ diffdir(char *p1, char *p2, int flags) status |= 2; return; } - if (path1[dirlen1 - 1] != '/') { - path1[dirlen1++] = '/'; - path1[dirlen1] = '\0'; - } + while (dirlen1 > 1 && path1[dirlen1 - 1] == '/') + path1[--dirlen1] = '\0'; dirlen2 = strlcpy(path2, *p2 ? p2 : ".", sizeof(path2)); if (dirlen2 >= sizeof(path2) - 1) { warnc(ENAMETOOLONG, "%s", p2); status |= 2; return; } - if (path2[dirlen2 - 1] != '/') { - path2[dirlen2++] = '/'; - path2[dirlen2] = '\0'; - } + while (dirlen2 > 1 && path2[dirlen2 - 1] == '/') + path2[--dirlen2] = '\0'; /* * Get a list of entries in each directory, skipping "excluded" files * and sorting alphabetically. */ - pos = scandir(path1, &dirp1, selectfile, alphasort); + pos = vscandir(&v1, path1, &dirp1, selectfile, alphasort); if (pos == -1) { if (errno == ENOENT && (Nflag || Pflag)) { pos = 0; @@ -93,7 +146,7 @@ diffdir(char *p1, char *p2, int flags) dp1 = dirp1; edp1 = dirp1 + pos; - pos = scandir(path2, &dirp2, selectfile, alphasort); + pos = vscandir(&v2, path2, &dirp2, selectfile, alphasort); if (pos == -1) { if (errno == ENOENT && Nflag) { pos = 0; @@ -115,6 +168,18 @@ diffdir(char *p1, char *p2, int flags) dp2++; } + /* + * Append separator so children's names can be appended directly. + */ + if (path1[dirlen1 - 1] != '/') { + path1[dirlen1++] = '/'; + path1[dirlen1] = '\0'; + } + if (path2[dirlen2 - 1] != '/') { + path2[dirlen2++] = '/'; + path2[dirlen2] = '\0'; + } + /* * Iterate through the two directory lists, diffing as we go. */ diff --git a/usr.bin/diff/tests/diff_test.sh b/usr.bin/diff/tests/diff_test.sh index c29c0a93d5d8..2efb2a844078 100755 --- a/usr.bin/diff/tests/diff_test.sh +++ b/usr.bin/diff/tests/diff_test.sh @@ -23,6 +23,7 @@ atf_test_case binary atf_test_case functionname atf_test_case noderef atf_test_case ignorecase +atf_test_case dirloop simple_body() { @@ -360,6 +361,21 @@ ignorecase_body() atf_check -o empty -s exit:0 diff -u -r --ignore-file-name-case A B } +dirloop_head() +{ + atf_set "timeout" "10" +} +dirloop_body() +{ + atf_check mkdir -p a/foo/bar + atf_check ln -s .. a/foo/bar/up + atf_check cp -a a b + atf_check \ + -e match:"a/foo/bar/up: Directory loop detected" \ + -e match:"b/foo/bar/up: Directory loop detected" \ + diff -r a b +} + atf_init_test_cases() { atf_add_test_case simple @@ -386,4 +402,5 @@ atf_init_test_cases() atf_add_test_case functionname atf_add_test_case noderef atf_add_test_case ignorecase + atf_add_test_case dirloop }home | help
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