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libarchive/backport-CVE-2021-31566.patch

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fix CVE-2021-36976,CVE-2021-31566,fix fuzz test
2022-04-09 09:46:01 +08:00
From ede459d2ebb879f5eedb6f7abea203be0b334230 Mon Sep 17 00:00:00 2001
From: Martin Matuska <martin@matuska.org>
Date: Wed, 17 Nov 2021 21:06:00 +0100
Subject: [PATCH] archive_write_disk_posix: fix writing fflags broken in
8a1bd5c
The fixup list was erroneously assumed to be directories only.
Only in the case of critical file flags modification (e.g. SF_IMMUTABLE
on BSD systems), other file types (e.g. regular files or symbolic links)
may be added to the fixup list. We still need to verify that we are writing
to the correct file type, so compare the archive entry file type with
the file type of the file to be modified.
Fixes #1617
Conflict:NA
Reference:https://github.com/libarchive/libarchive/commit/ede459d2ebb879f5eedb6f7abea203be0b334230
说明:这是CVE-2021-31556的后置补丁，CVE-2021-31556虽然已在基线tar包修复，但我们仍然建议合入该补丁，并且以该CVE号来命名
---
libarchive/archive_write_disk_posix.c | 87 +++++++++++++++++++++++----
1 file changed, 75 insertions(+), 12 deletions(-)
diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c
index aadc58718..7e57aac2e 100644
--- a/libarchive/archive_write_disk_posix.c
+++ b/libarchive/archive_write_disk_posix.c
@@ -173,6 +173,7 @@ struct fixup_entry {
struct fixup_entry *next;
struct archive_acl acl;
mode_t mode;
+ __LA_MODE_T filetype;
int64_t atime;
int64_t birthtime;
int64_t mtime;
@@ -357,6 +358,7 @@ struct archive_write_disk {
static int la_opendirat(int, const char *);
static int la_mktemp(struct archive_write_disk *);
+static int la_verify_filetype(mode_t, __LA_MODE_T);
static void fsobj_error(int *, struct archive_string *, int, const char *,
const char *);
static int check_symlinks_fsobj(char *, int *, struct archive_string *,
@@ -464,6 +466,39 @@ la_opendirat(int fd, const char *path) {
#endif
}
+static int
+la_verify_filetype(mode_t mode, __LA_MODE_T filetype) {
+ int ret = 0;
+
+ switch (filetype) {
+ case AE_IFREG:
+ ret = (S_ISREG(mode));
+ break;
+ case AE_IFDIR:
+ ret = (S_ISDIR(mode));
+ break;
+ case AE_IFLNK:
+ ret = (S_ISLNK(mode));
+ break;
+ case AE_IFSOCK:
+ ret = (S_ISSOCK(mode));
+ break;
+ case AE_IFCHR:
+ ret = (S_ISCHR(mode));
+ break;
+ case AE_IFBLK:
+ ret = (S_ISBLK(mode));
+ break;
+ case AE_IFIFO:
+ ret = (S_ISFIFO(mode));
+ break;
+ default:
+ break;
+ }
+
+ return (ret);
+}
+
static int
lazy_stat(struct archive_write_disk *a)
{
@@ -822,6 +857,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
fe = current_fixup(a, archive_entry_pathname(entry));
if (fe == NULL)
return (ARCHIVE_FATAL);
+ fe->filetype = archive_entry_filetype(entry);
fe->fixup |= TODO_MODE_BASE;
fe->mode = a->mode;
}
@@ -832,6 +868,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
fe = current_fixup(a, archive_entry_pathname(entry));
if (fe == NULL)
return (ARCHIVE_FATAL);
+ fe->filetype = archive_entry_filetype(entry);
fe->mode = a->mode;
fe->fixup |= TODO_TIMES;
if (archive_entry_atime_is_set(entry)) {
@@ -865,6 +902,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
fe = current_fixup(a, archive_entry_pathname(entry));
if (fe == NULL)
return (ARCHIVE_FATAL);
+ fe->filetype = archive_entry_filetype(entry);
fe->fixup |= TODO_ACLS;
archive_acl_copy(&fe->acl, archive_entry_acl(entry));
}
@@ -877,6 +915,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
fe = current_fixup(a, archive_entry_pathname(entry));
if (fe == NULL)
return (ARCHIVE_FATAL);
+ fe->filetype = archive_entry_filetype(entry);
fe->mac_metadata = malloc(metadata_size);
if (fe->mac_metadata != NULL) {
memcpy(fe->mac_metadata, metadata,
@@ -891,6 +930,7 @@ _archive_write_disk_header(struct archive *_a, struct archive_entry *entry)
fe = current_fixup(a, archive_entry_pathname(entry));
if (fe == NULL)
return (ARCHIVE_FATAL);
+ fe->filetype = archive_entry_filetype(entry);
fe->fixup |= TODO_FFLAGS;
/* TODO: Complete this.. defer fflags from below. */
}
@@ -2463,7 +2503,7 @@ _archive_write_disk_close(struct archive *_a)
struct fixup_entry *next, *p;
struct stat st;
char *c;
- int fd, ret;
+ int fd, ret, openflags;
archive_check_magic(&a->archive, ARCHIVE_WRITE_DISK_MAGIC,
ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA,
@@ -2490,32 +2530,53 @@ _archive_write_disk_close(struct archive *_a)
if (p->fixup == 0)
goto skip_fixup_entry;
else {
- fd = open(p->name, O_BINARY | O_NOFOLLOW | O_RDONLY
+ /*
+ * We need to verify if the type of the file
+ * we are going to open matches the file type
+ * of the fixup entry.
+ */
+ openflags = O_BINARY | O_NOFOLLOW | O_RDONLY
+ | O_CLOEXEC;
#if defined(O_DIRECTORY)
- | O_DIRECTORY
+ if (p->filetype == AE_IFDIR)
+ openflags |= O_DIRECTORY;
#endif
- | O_CLOEXEC);
+ fd = open(p->name, openflags);
+
+#if defined(O_DIRECTORY)
/*
- ` * If we don't support O_DIRECTORY,
- * or open() has failed, we must stat()
- * to verify that we are opening a directory
+ * If we support O_DIRECTORY and open was
+ * successful we can skip the file type check
+ * for directories. For other file types
+ * we need to verify via fstat() or lstat()
*/
-#if defined(O_DIRECTORY)
- if (fd == -1) {
+ if (fd == -1 || p->filetype != AE_IFDIR) {
+#if HAVE_FSTAT
+ if (fd > 0 && (
+ fstat(fd, &st) != 0 ||
+ la_verify_filetype(st.st_mode,
+ p->filetype) == 0)) {
+ goto skip_fixup_entry;
+ } else
+#endif
if (lstat(p->name, &st) != 0 ||
- !S_ISDIR(st.st_mode)) {
+ la_verify_filetype(st.st_mode,
+ p->filetype) == 0) {
goto skip_fixup_entry;
}
}
#else
#if HAVE_FSTAT
if (fd > 0 && (
- fstat(fd, &st) != 0 || !S_ISDIR(st.st_mode))) {
+ fstat(fd, &st) != 0 ||
+ la_verify_filetype(st.st_mode,
+ p->filetype) == 0)) {
goto skip_fixup_entry;
} else
#endif
if (lstat(p->name, &st) != 0 ||
- !S_ISDIR(st.st_mode)) {
+ la_verify_filetype(st.st_mode,
+ p->filetype) == 0) {
goto skip_fixup_entry;
}
#endif
@@ -2689,6 +2750,7 @@ new_fixup(struct archive_write_disk *a, const char *pathname)
fe->next = a->fixup_list;
a->fixup_list = fe;
fe->fixup = 0;
+ fe->filetype = 0;
fe->name = strdup(pathname);
return (fe);
}
@@ -3811,6 +3873,7 @@ set_fflags(struct archive_write_disk *a)
le = current_fixup(a, a->name);
if (le == NULL)
return (ARCHIVE_FATAL);
+ le->filetype = archive_entry_filetype(a->entry);
le->fixup |= TODO_FFLAGS;
le->fflags_set = set;
/* Store the mode if it's not already there. */
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