git: fix CVE-2023-25652

Git is a revision control system. Prior to versions 2.30.9, 2.31.8, 2.32.7,
2.33.8, 2.34.8, 2.35.8, 2.36.6, 2.37.7, 2.38.5, 2.39.3, and 2.40.1, by feeding
specially crafted input to `git apply --reject`, a path outside the working
tree can be overwritten with partially controlled contents (corresponding to
the rejected hunk(s) from the given patch). A fix is available in versions
2.30.9, 2.31.8, 2.32.7, 2.33.8, 2.34.8, 2.35.8, 2.36.6, 2.37.7, 2.38.5, 2.39.3,
and 2.40.1. As a workaround, avoid using `git apply` with `--reject` when applying
patches from an untrusted source. Use `git apply --stat` to inspect a patch before
applying; avoid applying one that create a conflict where a link corresponding to
the `*.rej` file exists.

References:
https://nvd.nist.gov/vuln/detail/CVE-2023-25652

Upstream patches:
https://github.com/git/git/commit/9db05711c98efc14f414d4c87135a34c13586e0b

(From OE-Core rev: 335ad8a6d795cd94b872370e44a033ce3fbf4890)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 95 insertions, 0 deletions

diff --git a/meta/recipes-devtools/git/git/CVE-2023-25652.patch b/meta/recipes-devtools/git/git/CVE-2023-25652.patch
new file mode 100644
index 0000000000..825701eaff
--- /dev/null
+++ b/meta/recipes-devtools/git/git/CVE-2023-25652.patch
@@ -0,0 +1,94 @@
+From 9db05711c98efc14f414d4c87135a34c13586e0b Mon Sep 17 00:00:00 2001
+From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
+Date: Thu Mar 9 16:02:54 2023 +0100
+Subject: [PATCH] apply --reject: overwrite existing `.rej` symlink if it
+ exists
+
+   The `git apply --reject` is expected to write out `.rej` files in case
+   one or more hunks fail to apply cleanly. Historically, the command
+   overwrites any existing `.rej` files. The idea being that
+   apply/reject/edit cycles are relatively common, and the generated `.rej`
+   files are not considered precious.
+
+    But the command does not overwrite existing `.rej` symbolic links, and
+    instead follows them. This is unsafe because the same patch could
+    potentially create such a symbolic link and point at arbitrary paths
+    outside the current worktree, and `git apply` would write the contents
+    of the `.rej` file into that location.
+
+    Therefore, let's make sure that any existing `.rej` file or symbolic
+    link is removed before writing it.
+
+    Reported-by: RyotaK <ryotak.mail@gmail.com>
+    Helped-by: Taylor Blau <me@ttaylorr.com>
+    Helped-by: Junio C Hamano <gitster@pobox.com>
+    Helped-by: Linus Torvalds <torvalds@linuxfoundation.org>
+    Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
+
+CVE: CVE-2023-25652
+Upstream-Status: Backport [https://github.com/git/git/commit/9db05711c98efc14f414d4c87135a34c13586e0b]
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ apply.c                  | 14 ++++++++++++--
+ t/t4115-apply-symlink.sh | 15 +++++++++++++++
+ 2 files changed, 27 insertions(+), 2 deletions(-)
+
+diff --git a/apply.c b/apply.c
+index fc6f484..47f2686 100644
+--- a/apply.c
++++ b/apply.c
+@@ -4584,7 +4584,7 @@ static int write_out_one_reject(struct apply_state *state, struct patch *patch)
+        FILE *rej;
+        char namebuf[PATH_MAX];
+        struct fragment *frag;
+-       int cnt = 0;
++       int fd, cnt = 0;
+        struct strbuf sb = STRBUF_INIT;
+
+        for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
+@@ -4624,7 +4624,17 @@ static int write_out_one_reject(struct apply_state *state, struct patch *patch)
+        memcpy(namebuf, patch->new_name, cnt);
+        memcpy(namebuf + cnt, ".rej", 5);
+
+-       rej = fopen(namebuf, "w");
++       fd = open(namebuf, O_CREAT | O_EXCL | O_WRONLY, 0666);
++       if (fd < 0) {
++               if (errno != EEXIST)
++                       return error_errno(_("cannot open %s"), namebuf);
++               if (unlink(namebuf))
++                       return error_errno(_("cannot unlink '%s'"), namebuf);
++               fd = open(namebuf, O_CREAT | O_EXCL | O_WRONLY, 0666);
++               if (fd < 0)
++                       return error_errno(_("cannot open %s"), namebuf);
++       }
++       rej = fdopen(fd, "w");
+        if (!rej)
+                return error_errno(_("cannot open %s"), namebuf);
+
+diff --git a/t/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh
+index 65ac7df..e95e6d4 100755
+--- a/t/t4115-apply-symlink.sh
++++ b/t/t4115-apply-symlink.sh
+@@ -126,4 +126,19 @@ test_expect_success SYMLINKS 'symlink escape when deleting file' '
+        test_path_is_file .git/delete-me
+ '
+
++test_expect_success SYMLINKS '--reject removes .rej symlink if it exists' '
++       test_when_finished "git reset --hard && git clean -dfx" &&
++
++       test_commit file &&
++       echo modified >file.t &&
++       git diff -- file.t >patch &&
++       echo modified-again >file.t &&
++
++       ln -s foo file.t.rej &&
++       test_must_fail git apply patch --reject 2>err &&
++       test_i18ngrep "Rejected hunk" err &&
++       test_path_is_missing foo &&
++       test_path_is_file file.t.rej
++'
++
+ test_done
+--
+2.40.0
diff --git a/meta/recipes-devtools/git/git_2.35.7.bb b/meta/recipes-devtools/git/git_2.35.7.bb
index 199ac950fa..99d3d70683 100644
--- a/meta/recipes-devtools/git/git_2.35.7.bb
+++ b/meta/recipes-devtools/git/git_2.35.7.bb
@@ -11,6 +11,7 @@ SRC_URI = "${KERNELORG_MIRROR}/software/scm/git/git-${PV}.tar.gz;name=tarball \
            file://fixsort.patch \
            file://0001-config.mak.uname-do-not-force-RHEL-7-specific-build-.patch \
            file://CVE-2023-29007.patch \
+           file://CVE-2023-25652.patch \
            "
 
 S = "${WORKDIR}/git-${PV}"