On Tue, Mar 28, 2023 at 4:49 PM Vijay Anusuri <vanus...@mvista.com> wrote: > > Hi Team, > > Any update for this patch?
Not sure how I missed this, but I've got it now! Thanks for the reminder. Steve > > Thanks & Regards, > Vijay > > On Mon, Mar 20, 2023 at 2:42 PM <vanus...@mvista.com> wrote: >> >> From: Vijay Anusuri <vanus...@mvista.com> >> >> Upstream-Status: Backport from >> https://github.com/git/git/commit/58325b93c5b6212697b088371809e9948fee8052 >> & >> https://github.com/git/git/commit/cf8f6ce02a13f4d1979a53241afbee15a293fce9 >> & https://github.com/git/git/commit/bffc762f87ae8d18c6001bf0044a76004245754c >> >> Signed-off-by: Vijay Anusuri <vanus...@mvista.com> >> --- >> .../git/files/CVE-2023-22490-1.patch | 179 +++++++++++++++++ >> .../git/files/CVE-2023-22490-2.patch | 122 ++++++++++++ >> .../git/files/CVE-2023-22490-3.patch | 154 +++++++++++++++ >> .../git/files/CVE-2023-23946.patch | 184 ++++++++++++++++++ >> meta/recipes-devtools/git/git.inc | 4 + >> 5 files changed, 643 insertions(+) >> create mode 100644 meta/recipes-devtools/git/files/CVE-2023-22490-1.patch >> create mode 100644 meta/recipes-devtools/git/files/CVE-2023-22490-2.patch >> create mode 100644 meta/recipes-devtools/git/files/CVE-2023-22490-3.patch >> create mode 100644 meta/recipes-devtools/git/files/CVE-2023-23946.patch >> >> diff --git a/meta/recipes-devtools/git/files/CVE-2023-22490-1.patch >> b/meta/recipes-devtools/git/files/CVE-2023-22490-1.patch >> new file mode 100644 >> index 0000000000..cc9b448c5c >> --- /dev/null >> +++ b/meta/recipes-devtools/git/files/CVE-2023-22490-1.patch >> @@ -0,0 +1,179 @@ >> +From 58325b93c5b6212697b088371809e9948fee8052 Mon Sep 17 00:00:00 2001 >> +From: Taylor Blau <m...@ttaylorr.com> >> +Date: Tue, 24 Jan 2023 19:43:45 -0500 >> +Subject: [PATCH 1/3] t5619: demonstrate clone_local() with ambiguous >> transport >> + >> +When cloning a repository, Git must determine (a) what transport >> +mechanism to use, and (b) whether or not the clone is local. >> + >> +Since f38aa83 (use local cloning if insteadOf makes a local URL, >> +2014-07-17), the latter check happens after the remote has been >> +initialized, and references the remote's URL instead of the local path. >> +This is done to make it possible for a `url.<base>.insteadOf` rule to >> +convert a remote URL into a local one, in which case the `clone_local()` >> +mechanism should be used. >> + >> +However, with a specially crafted repository, Git can be tricked into >> +using a non-local transport while still setting `is_local` to "1" and >> +using the `clone_local()` optimization. The below test case >> +demonstrates such an instance, and shows that it can be used to include >> +arbitrary (known) paths in the working copy of a cloned repository on a >> +victim's machine[^1], even if local file clones are forbidden by >> +`protocol.file.allow`. >> + >> +This happens in a few parts: >> + >> + 1. We first call `get_repo_path()` to see if the remote is a local >> + path. If it is, we replace the repo name with its absolute path. >> + >> + 2. We then call `transport_get()` on the repo name and decide how to >> + access it. If it was turned into an absolute path in the previous >> + step, then we should always treat it like a file. >> + >> + 3. We use `get_repo_path()` again, and set `is_local` as appropriate. >> + But it's already too late to rewrite the repo name as an absolute >> + path, since we've already fed it to the transport code. >> + >> +The attack works by including a submodule whose URL corresponds to a >> +path on disk. In the below example, the repository "sub" is reachable >> +via the dumb HTTP protocol at (something like): >> + >> + http://127.0.0.1:NNNN/dumb/sub.git >> + >> +However, the path "http:/127.0.0.1:NNNN/dumb" (that is, a top-level >> +directory called "http:", then nested directories "127.0.0.1:NNNN", and >> +"dumb") exists within the repository, too. >> + >> +To determine this, it first picks the appropriate transport, which is >> +dumb HTTP. It then uses the remote's URL in order to determine whether >> +the repository exists locally on disk. However, the malicious repository >> +also contains an embedded stub repository which is the target of a >> +symbolic link at the local path corresponding to the "sub" repository on >> +disk (i.e., there is a symbolic link at "http:/127.0.0.1/dumb/sub.git", >> +pointing to the stub repository via ".git/modules/sub/../../../repo"). >> + >> +This stub repository fools Git into thinking that a local repository >> +exists at that URL and thus can be cloned locally. The affected call is >> +in `get_repo_path()`, which in turn calls `get_repo_path_1()`, which >> +locates a valid repository at that target. >> + >> +This then causes Git to set the `is_local` variable to "1", and in turn >> +instructs Git to clone the repository using its local clone optimization >> +via the `clone_local()` function. >> + >> +The exploit comes into play because the stub repository's top-level >> +"$GIT_DIR/objects" directory is a symbolic link which can point to an >> +arbitrary path on the victim's machine. `clone_local()` resolves the >> +top-level "objects" directory through a `stat(2)` call, meaning that we >> +read through the symbolic link and copy or hardlink the directory >> +contents at the destination of the link. >> + >> +In other words, we can get steps (1) and (3) to disagree by leveraging >> +the dangling symlink to pick a non-local transport in the first step, >> +and then set is_local to "1" in the third step when cloning with >> +`--separate-git-dir`, which makes the symlink non-dangling. >> + >> +This can result in data-exfiltration on the victim's machine when >> +sensitive data is at a known path (e.g., "/home/$USER/.ssh"). >> + >> +The appropriate fix is two-fold: >> + >> + - Resolve the transport later on (to avoid using the local >> + clone optimization with a non-local transport). >> + >> + - Avoid reading through the top-level "objects" directory when >> + (correctly) using the clone_local() optimization. >> + >> +This patch merely demonstrates the issue. The following two patches will >> +implement each part of the above fix, respectively. >> + >> +[^1]: Provided that any target directory does not contain symbolic >> + links, in which case the changes from 6f054f9 (builtin/clone.c: >> + disallow `--local` clones with symlinks, 2022-07-28) will abort the >> + clone. >> + >> +Reported-by: yvvdwf <yvv...@gmail.com> >> +Signed-off-by: Taylor Blau <m...@ttaylorr.com> >> +Signed-off-by: Junio C Hamano <gits...@pobox.com> >> + >> +Upstream-Status: Backport >> +[https://github.com/git/git/commit/58325b93c5b6212697b088371809e9948fee8052] >> +CVE: CVE-2023-22490 >> +Signed-off-by: Vijay Anusuri <vanus...@mvista.com> >> +--- >> + t/t5619-clone-local-ambiguous-transport.sh | 63 ++++++++++++++++++++++ >> + 1 file changed, 63 insertions(+) >> + create mode 100644 t/t5619-clone-local-ambiguous-transport.sh >> + >> +diff --git a/t/t5619-clone-local-ambiguous-transport.sh >> b/t/t5619-clone-local-ambiguous-transport.sh >> +new file mode 100644 >> +index 0000000..7ebd31a >> +--- /dev/null >> ++++ b/t/t5619-clone-local-ambiguous-transport.sh >> +@@ -0,0 +1,63 @@ >> ++#!/bin/sh >> ++ >> ++test_description='test local clone with ambiguous transport' >> ++ >> ++. ./test-lib.sh >> ++. "$TEST_DIRECTORY/lib-httpd.sh" >> ++ >> ++if ! test_have_prereq SYMLINKS >> ++then >> ++ skip_all='skipping test, symlink support unavailable' >> ++ test_done >> ++fi >> ++ >> ++start_httpd >> ++ >> ++REPO="$HTTPD_DOCUMENT_ROOT_PATH/sub.git" >> ++URI="$HTTPD_URL/dumb/sub.git" >> ++ >> ++test_expect_success 'setup' ' >> ++ mkdir -p sensitive && >> ++ echo "secret" >sensitive/secret && >> ++ >> ++ git init --bare "$REPO" && >> ++ test_commit_bulk -C "$REPO" --ref=main 1 && >> ++ >> ++ git -C "$REPO" update-ref HEAD main && >> ++ git -C "$REPO" update-server-info && >> ++ >> ++ git init malicious && >> ++ ( >> ++ cd malicious && >> ++ >> ++ git submodule add "$URI" && >> ++ >> ++ mkdir -p repo/refs && >> ++ touch repo/refs/.gitkeep && >> ++ printf "ref: refs/heads/a" >repo/HEAD && >> ++ ln -s "$(cd .. && pwd)/sensitive" repo/objects && >> ++ >> ++ mkdir -p "$HTTPD_URL/dumb" && >> ++ ln -s "../../../.git/modules/sub/../../../repo/" "$URI" && >> ++ >> ++ git add . && >> ++ git commit -m "initial commit" >> ++ ) && >> ++ >> ++ # Delete all of the references in our malicious submodule to >> ++ # avoid the client attempting to checkout any objects (which >> ++ # will be missing, and thus will cause the clone to fail before >> ++ # we can trigger the exploit). >> ++ git -C "$REPO" for-each-ref --format="delete %(refname)" >in && >> ++ git -C "$REPO" update-ref --stdin <in && >> ++ git -C "$REPO" update-server-info >> ++' >> ++ >> ++test_expect_failure 'ambiguous transport does not lead to arbitrary >> file-inclusion' ' >> ++ git clone malicious clone && >> ++ git -C clone submodule update --init && >> ++ >> ++ test_path_is_missing clone/.git/modules/sub/objects/secret >> ++' >> ++ >> ++test_done >> +-- >> +2.25.1 >> + >> diff --git a/meta/recipes-devtools/git/files/CVE-2023-22490-2.patch >> b/meta/recipes-devtools/git/files/CVE-2023-22490-2.patch >> new file mode 100644 >> index 0000000000..0b5b40f827 >> --- /dev/null >> +++ b/meta/recipes-devtools/git/files/CVE-2023-22490-2.patch >> @@ -0,0 +1,122 @@ >> +From cf8f6ce02a13f4d1979a53241afbee15a293fce9 Mon Sep 17 00:00:00 2001 >> +From: Taylor Blau <m...@ttaylorr.com> >> +Date: Tue, 24 Jan 2023 19:43:48 -0500 >> +Subject: [PATCH 2/3] clone: delay picking a transport until after >> get_repo_path() >> + >> +In the previous commit, t5619 demonstrates an issue where two calls to >> +`get_repo_path()` could trick Git into using its local clone mechanism >> +in conjunction with a non-local transport. >> + >> +That sequence is: >> + >> + - the starting state is that the local path https:/example.com/foo is a >> + symlink that points to ../../../.git/modules/foo. So it's dangling. >> + >> + - get_repo_path() sees that no such path exists (because it's >> + dangling), and thus we do not canonicalize it into an absolute path >> + >> + - because we're using --separate-git-dir, we create .git/modules/foo. >> + Now our symlink is no longer dangling! >> + >> + - we pass the url to transport_get(), which sees it as an https URL. >> + >> + - we call get_repo_path() again, on the url. This second call was >> + introduced by f38aa83 (use local cloning if insteadOf makes a >> + local URL, 2014-07-17). The idea is that we want to pull the url >> + fresh from the remote.c API, because it will apply any aliases. >> + >> +And of course now it sees that there is a local file, which is a >> +mismatch with the transport we already selected. >> + >> +The issue in the above sequence is calling `transport_get()` before >> +deciding whether or not the repository is indeed local, and not passing >> +in an absolute path if it is local. >> + >> +This is reminiscent of a similar bug report in [1], where it was >> +suggested to perform the `insteadOf` lookup earlier. Taking that >> +approach may not be as straightforward, since the intent is to store the >> +original URL in the config, but to actually fetch from the insteadOf >> +one, so conflating the two early on is a non-starter. >> + >> +Note: we pass the path returned by `get_repo_path(remote->url[0])`, >> +which should be the same as `repo_name` (aside from any `insteadOf` >> +rewrites). >> + >> +We *could* pass `absolute_pathdup()` of the same argument, which >> +86521ac (Bring local clone's origin URL in line with that of a remote >> +clone, 2008-09-01) indicates may differ depending on the presence of >> +".git/" for a non-bare repo. That matters for forming relative submodule >> +paths, but doesn't matter for the second call, since we're just feeding >> +it to the transport code, which is fine either way. >> + >> +[1]: >> https://lore.kernel.org/git/CAMoD=bi41mb3qrn3jdzl-fghs4w3c2jgpnjb-cqsndo7fmt...@mail.gmail.com/ >> + >> +Signed-off-by: Jeff King <p...@peff.net> >> +Signed-off-by: Taylor Blau <m...@ttaylorr.com> >> +Signed-off-by: Junio C Hamano <gits...@pobox.com> >> + >> +Upstream-Status: Backport >> +[https://github.com/git/git/commit/cf8f6ce02a13f4d1979a53241afbee15a293fce9] >> +CVE: CVE-2023-22490 >> +Signed-off-by: Vijay Anusuri <vanus...@mvista.com> >> +--- >> + builtin/clone.c | 8 ++++---- >> + t/t5619-clone-local-ambiguous-transport.sh | 15 +++++++++++---- >> + 2 files changed, 15 insertions(+), 8 deletions(-) >> + >> +diff --git a/builtin/clone.c b/builtin/clone.c >> +index 53e04b1..b57e703 100644 >> +--- a/builtin/clone.c >> ++++ b/builtin/clone.c >> +@@ -1112,10 +1112,6 @@ int cmd_clone(int argc, const char **argv, const >> char *prefix) >> + branch_top.buf); >> + refspec_append(&remote->fetch, default_refspec.buf); >> + >> +- transport = transport_get(remote, remote->url[0]); >> +- transport_set_verbosity(transport, option_verbosity, >> option_progress); >> +- transport->family = family; >> +- >> + path = get_repo_path(remote->url[0], &is_bundle); >> + is_local = option_local != 0 && path && !is_bundle; >> + if (is_local) { >> +@@ -1135,6 +1131,10 @@ int cmd_clone(int argc, const char **argv, const >> char *prefix) >> + } >> + if (option_local > 0 && !is_local) >> + warning(_("--local is ignored")); >> ++ >> ++ transport = transport_get(remote, path ? path : remote->url[0]); >> ++ transport_set_verbosity(transport, option_verbosity, >> option_progress); >> ++ transport->family = family; >> + transport->cloning = 1; >> + >> + transport_set_option(transport, TRANS_OPT_KEEP, "yes"); >> +diff --git a/t/t5619-clone-local-ambiguous-transport.sh >> b/t/t5619-clone-local-ambiguous-transport.sh >> +index 7ebd31a..cce62bf 100644 >> +--- a/t/t5619-clone-local-ambiguous-transport.sh >> ++++ b/t/t5619-clone-local-ambiguous-transport.sh >> +@@ -53,11 +53,18 @@ test_expect_success 'setup' ' >> + git -C "$REPO" update-server-info >> + ' >> + >> +-test_expect_failure 'ambiguous transport does not lead to arbitrary >> file-inclusion' ' >> ++test_expect_success 'ambiguous transport does not lead to arbitrary >> file-inclusion' ' >> + git clone malicious clone && >> +- git -C clone submodule update --init && >> +- >> +- test_path_is_missing clone/.git/modules/sub/objects/secret >> ++ test_must_fail git -C clone submodule update --init 2>err && >> ++ >> ++ test_path_is_missing clone/.git/modules/sub/objects/secret && >> ++ # We would actually expect "transport .file. not allowed" here, >> ++ # but due to quirks of the URL detection in Git, we mis-parse >> ++ # the absolute path as a bogus URL and die before that step. >> ++ # >> ++ # This works for now, and if we ever fix the URL detection, it >> ++ # is OK to change this to detect the transport error. >> ++ grep "protocol .* is not supported" err >> + ' >> + >> + test_done >> +-- >> +2.25.1 >> + >> diff --git a/meta/recipes-devtools/git/files/CVE-2023-22490-3.patch >> b/meta/recipes-devtools/git/files/CVE-2023-22490-3.patch >> new file mode 100644 >> index 0000000000..08fb7f840b >> --- /dev/null >> +++ b/meta/recipes-devtools/git/files/CVE-2023-22490-3.patch >> @@ -0,0 +1,154 @@ >> +From bffc762f87ae8d18c6001bf0044a76004245754c Mon Sep 17 00:00:00 2001 >> +From: Taylor Blau <m...@ttaylorr.com> >> +Date: Tue, 24 Jan 2023 19:43:51 -0500 >> +Subject: [PATCH 3/3] dir-iterator: prevent top-level symlinks without >> FOLLOW_SYMLINKS >> + >> +When using the dir_iterator API, we first stat(2) the base path, and >> +then use that as a starting point to enumerate the directory's contents. >> + >> +If the directory contains symbolic links, we will immediately die() upon >> +encountering them without the `FOLLOW_SYMLINKS` flag. The same is not >> +true when resolving the top-level directory, though. >> + >> +As explained in a previous commit, this oversight in 6f054f9 >> +(builtin/clone.c: disallow `--local` clones with symlinks, 2022-07-28) >> +can be used as an attack vector to include arbitrary files on a victim's >> +filesystem from outside of the repository. >> + >> +Prevent resolving top-level symlinks unless the FOLLOW_SYMLINKS flag is >> +given, which will cause clones of a repository with a symlink'd >> +"$GIT_DIR/objects" directory to fail. >> + >> +Signed-off-by: Taylor Blau <m...@ttaylorr.com> >> +Signed-off-by: Junio C Hamano <gits...@pobox.com> >> + >> +Upstream-Status: Backport >> +[https://github.com/git/git/commit/bffc762f87ae8d18c6001bf0044a76004245754c] >> +CVE: CVE-2023-22490 >> +Signed-off-by: Vijay Anusuri <vanus...@mvista.com> >> +--- >> + dir-iterator.c | 13 +++++++++---- >> + dir-iterator.h | 5 +++++ >> + t/t0066-dir-iterator.sh | 27 ++++++++++++++++++++++++++- >> + t/t5604-clone-reference.sh | 16 ++++++++++++++++ >> + 4 files changed, 56 insertions(+), 5 deletions(-) >> + >> +diff --git a/dir-iterator.c b/dir-iterator.c >> +index b17e9f9..3764dd8 100644 >> +--- a/dir-iterator.c >> ++++ b/dir-iterator.c >> +@@ -203,7 +203,7 @@ struct dir_iterator *dir_iterator_begin(const char >> *path, unsigned int flags) >> + { >> + struct dir_iterator_int *iter = xcalloc(1, sizeof(*iter)); >> + struct dir_iterator *dir_iterator = &iter->base; >> +- int saved_errno; >> ++ int saved_errno, err; >> + >> + strbuf_init(&iter->base.path, PATH_MAX); >> + strbuf_addstr(&iter->base.path, path); >> +@@ -213,10 +213,15 @@ struct dir_iterator *dir_iterator_begin(const char >> *path, unsigned int flags) >> + iter->flags = flags; >> + >> + /* >> +- * Note: stat already checks for NULL or empty strings and >> +- * inexistent paths. >> ++ * Note: stat/lstat already checks for NULL or empty strings and >> ++ * nonexistent paths. >> + */ >> +- if (stat(iter->base.path.buf, &iter->base.st) < 0) { >> ++ if (iter->flags & DIR_ITERATOR_FOLLOW_SYMLINKS) >> ++ err = stat(iter->base.path.buf, &iter->base.st); >> ++ else >> ++ err = lstat(iter->base.path.buf, &iter->base.st); >> ++ >> ++ if (err < 0) { >> + saved_errno = errno; >> + goto error_out; >> + } >> +diff --git a/dir-iterator.h b/dir-iterator.h >> +index 0822915..e3b6ff2 100644 >> +--- a/dir-iterator.h >> ++++ b/dir-iterator.h >> +@@ -61,6 +61,11 @@ >> + * not the symlinks themselves, which is the default behavior. Broken >> + * symlinks are ignored. >> + * >> ++ * Note: setting DIR_ITERATOR_FOLLOW_SYMLINKS affects resolving the >> ++ * starting path as well (e.g., attempting to iterate starting at a >> ++ * symbolic link pointing to a directory without FOLLOW_SYMLINKS will >> ++ * result in an error). >> ++ * >> + * Warning: circular symlinks are also followed when >> + * DIR_ITERATOR_FOLLOW_SYMLINKS is set. The iteration may end up with >> + * an ELOOP if they happen and DIR_ITERATOR_PEDANTIC is set. >> +diff --git a/t/t0066-dir-iterator.sh b/t/t0066-dir-iterator.sh >> +index 92910e4..c826f60 100755 >> +--- a/t/t0066-dir-iterator.sh >> ++++ b/t/t0066-dir-iterator.sh >> +@@ -109,7 +109,9 @@ test_expect_success SYMLINKS 'setup dirs with symlinks' >> ' >> + mkdir -p dir5/a/c && >> + ln -s ../c dir5/a/b/d && >> + ln -s ../ dir5/a/b/e && >> +- ln -s ../../ dir5/a/b/f >> ++ ln -s ../../ dir5/a/b/f && >> ++ >> ++ ln -s dir4 dir6 >> + ' >> + >> + test_expect_success SYMLINKS 'dir-iterator should not follow symlinks by >> default' ' >> +@@ -145,4 +147,27 @@ test_expect_success SYMLINKS 'dir-iterator should >> follow symlinks w/ follow flag >> + test_cmp expected-follow-sorted-output actual-follow-sorted-output >> + ' >> + >> ++test_expect_success SYMLINKS 'dir-iterator does not resolve top-level >> symlinks' ' >> ++ test_must_fail test-tool dir-iterator ./dir6 >out && >> ++ >> ++ grep "ENOTDIR" out >> ++' >> ++ >> ++test_expect_success SYMLINKS 'dir-iterator resolves top-level symlinks w/ >> follow flag' ' >> ++ cat >expected-follow-sorted-output <<-EOF && >> ++ [d] (a) [a] ./dir6/a >> ++ [d] (a/f) [f] ./dir6/a/f >> ++ [d] (a/f/c) [c] ./dir6/a/f/c >> ++ [d] (b) [b] ./dir6/b >> ++ [d] (b/c) [c] ./dir6/b/c >> ++ [f] (a/d) [d] ./dir6/a/d >> ++ [f] (a/e) [e] ./dir6/a/e >> ++ EOF >> ++ >> ++ test-tool dir-iterator --follow-symlinks ./dir6 >out && >> ++ sort out >actual-follow-sorted-output && >> ++ >> ++ test_cmp expected-follow-sorted-output actual-follow-sorted-output >> ++' >> ++ >> + test_done >> +diff --git a/t/t5604-clone-reference.sh b/t/t5604-clone-reference.sh >> +index 4894237..615b981 100755 >> +--- a/t/t5604-clone-reference.sh >> ++++ b/t/t5604-clone-reference.sh >> +@@ -354,4 +354,20 @@ test_expect_success SYMLINKS 'clone repo with >> symlinked or unknown files at obje >> + test_must_be_empty T--shared.objects-symlinks.raw >> + ' >> + >> ++test_expect_success SYMLINKS 'clone repo with symlinked objects directory' >> ' >> ++ test_when_finished "rm -fr sensitive malicious" && >> ++ >> ++ mkdir -p sensitive && >> ++ echo "secret" >sensitive/file && >> ++ >> ++ git init malicious && >> ++ rm -fr malicious/.git/objects && >> ++ ln -s "$(pwd)/sensitive" ./malicious/.git/objects && >> ++ >> ++ test_must_fail git clone --local malicious clone 2>err && >> ++ >> ++ test_path_is_missing clone && >> ++ grep "failed to start iterator over" err >> ++' >> ++ >> + test_done >> +-- >> +2.25.1 >> + >> diff --git a/meta/recipes-devtools/git/files/CVE-2023-23946.patch >> b/meta/recipes-devtools/git/files/CVE-2023-23946.patch >> new file mode 100644 >> index 0000000000..3629ff57b2 >> --- /dev/null >> +++ b/meta/recipes-devtools/git/files/CVE-2023-23946.patch >> @@ -0,0 +1,184 @@ >> +From fade728df1221598f42d391cf377e9e84a32053f Mon Sep 17 00:00:00 2001 >> +From: Patrick Steinhardt <p...@pks.im> >> +Date: Thu, 2 Feb 2023 11:54:34 +0100 >> +Subject: [PATCH] apply: fix writing behind newly created symbolic links >> + >> +When writing files git-apply(1) initially makes sure that none of the >> +files it is about to create are behind a symlink: >> + >> +``` >> + $ git init repo >> + Initialized empty Git repository in /tmp/repo/.git/ >> + $ cd repo/ >> + $ ln -s dir symlink >> + $ git apply - <<EOF >> + diff --git a/symlink/file b/symlink/file >> + new file mode 100644 >> + index 0000000..e69de29 >> + EOF >> + error: affected file 'symlink/file' is beyond a symbolic link >> +``` >> + >> +This safety mechanism is crucial to ensure that we don't write outside >> +of the repository's working directory. It can be fooled though when the >> +patch that is being applied creates the symbolic link in the first >> +place, which can lead to writing files in arbitrary locations. >> + >> +Fix this by checking whether the path we're about to create is >> +beyond a symlink or not. Tightening these checks like this should be >> +fine as we already have these precautions in Git as explained >> +above. Ideally, we should update the check we do up-front before >> +starting to reflect the computed changes to the working tree so that >> +we catch this case as well, but as part of embargoed security work, >> +adding an equivalent check just before we try to write out a file >> +should serve us well as a reasonable first step. >> + >> +Digging back into history shows that this vulnerability has existed >> +since at least Git v2.9.0. As Git v2.8.0 and older don't build on my >> +system anymore I cannot tell whether older versions are affected, as >> +well. >> + >> +Reported-by: Joern Schneeweisz <jschneewe...@gitlab.com> >> +Signed-off-by: Patrick Steinhardt <p...@pks.im> >> +Signed-off-by: Junio C Hamano <gits...@pobox.com> >> + >> +Upstream-Status: Backport >> +[https://github.com/git/git/commit/fade728df1221598f42d391cf377e9e84a32053f] >> +CVE: CVE-2023-23946 >> +Signed-off-by: Vijay Anusuri <vanus...@mvista.com> >> +--- >> + apply.c | 27 ++++++++++++++ >> + t/t4115-apply-symlink.sh | 81 ++++++++++++++++++++++++++++++++++++++++ >> + 2 files changed, 108 insertions(+) >> + >> +diff --git a/apply.c b/apply.c >> +index f8a046a..4f303bf 100644 >> +--- a/apply.c >> ++++ b/apply.c >> +@@ -4373,6 +4373,33 @@ static int create_one_file(struct apply_state *state, >> + if (state->cached) >> + return 0; >> + >> ++ /* >> ++ * We already try to detect whether files are beyond a symlink in our >> ++ * up-front checks. But in the case where symlinks are created by any >> ++ * of the intermediate hunks it can happen that our up-front checks >> ++ * didn't yet see the symlink, but at the point of arriving here >> there >> ++ * in fact is one. We thus repeat the check for symlinks here. >> ++ * >> ++ * Note that this does not make the up-front check obsolete as the >> ++ * failure mode is different: >> ++ * >> ++ * - The up-front checks cause us to abort before we have written >> ++ * anything into the working directory. So when we exit this way >> the >> ++ * working directory remains clean. >> ++ * >> ++ * - The checks here happen in the middle of the action where we have >> ++ * already started to apply the patch. The end result will be a >> dirty >> ++ * working directory. >> ++ * >> ++ * Ideally, we should update the up-front checks to catch what would >> ++ * happen when we apply the patch before we damage the working tree. >> ++ * We have all the information necessary to do so. But for now, as a >> ++ * part of embargoed security work, having this check would serve as >> a >> ++ * reasonable first step. >> ++ */ >> ++ if (path_is_beyond_symlink(state, path)) >> ++ return error(_("affected file '%s' is beyond a symbolic >> link"), path); >> ++ >> + res = try_create_file(state, path, mode, buf, size); >> + if (res < 0) >> + return -1; >> +diff --git a/t/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh >> +index 872fcda..1acb7b2 100755 >> +--- a/t/t4115-apply-symlink.sh >> ++++ b/t/t4115-apply-symlink.sh >> +@@ -44,4 +44,85 @@ test_expect_success 'apply --index symlink patch' ' >> + >> + ' >> + >> ++test_expect_success 'symlink setup' ' >> ++ ln -s .git symlink && >> ++ git add symlink && >> ++ git commit -m "add symlink" >> ++' >> ++ >> ++test_expect_success SYMLINKS 'symlink escape when creating new files' ' >> ++ test_when_finished "git reset --hard && git clean -dfx" && >> ++ >> ++ cat >patch <<-EOF && >> ++ diff --git a/symlink b/renamed-symlink >> ++ similarity index 100% >> ++ rename from symlink >> ++ rename to renamed-symlink >> ++ -- >> ++ diff --git /dev/null b/renamed-symlink/create-me >> ++ new file mode 100644 >> ++ index 0000000..039727e >> ++ --- /dev/null >> ++ +++ b/renamed-symlink/create-me >> ++ @@ -0,0 +1,1 @@ >> ++ +busted >> ++ EOF >> ++ >> ++ test_must_fail git apply patch 2>stderr && >> ++ cat >expected_stderr <<-EOF && >> ++ error: affected file ${SQ}renamed-symlink/create-me${SQ} is beyond a >> symbolic link >> ++ EOF >> ++ test_cmp expected_stderr stderr && >> ++ ! test_path_exists .git/create-me >> ++' >> ++ >> ++test_expect_success SYMLINKS 'symlink escape when modifying file' ' >> ++ test_when_finished "git reset --hard && git clean -dfx" && >> ++ touch .git/modify-me && >> ++ >> ++ cat >patch <<-EOF && >> ++ diff --git a/symlink b/renamed-symlink >> ++ similarity index 100% >> ++ rename from symlink >> ++ rename to renamed-symlink >> ++ -- >> ++ diff --git a/renamed-symlink/modify-me b/renamed-symlink/modify-me >> ++ index 1111111..2222222 100644 >> ++ --- a/renamed-symlink/modify-me >> ++ +++ b/renamed-symlink/modify-me >> ++ @@ -0,0 +1,1 @@ >> ++ +busted >> ++ EOF >> ++ >> ++ test_must_fail git apply patch 2>stderr && >> ++ cat >expected_stderr <<-EOF && >> ++ error: renamed-symlink/modify-me: No such file or directory >> ++ EOF >> ++ test_cmp expected_stderr stderr && >> ++ test_must_be_empty .git/modify-me >> ++' >> ++ >> ++test_expect_success SYMLINKS 'symlink escape when deleting file' ' >> ++ test_when_finished "git reset --hard && git clean -dfx && rm >> .git/delete-me" && >> ++ touch .git/delete-me && >> ++ >> ++ cat >patch <<-EOF && >> ++ diff --git a/symlink b/renamed-symlink >> ++ similarity index 100% >> ++ rename from symlink >> ++ rename to renamed-symlink >> ++ -- >> ++ diff --git a/renamed-symlink/delete-me b/renamed-symlink/delete-me >> ++ deleted file mode 100644 >> ++ index 1111111..0000000 100644 >> ++ EOF >> ++ >> ++ test_must_fail git apply patch 2>stderr && >> ++ cat >expected_stderr <<-EOF && >> ++ error: renamed-symlink/delete-me: No such file or directory >> ++ EOF >> ++ test_cmp expected_stderr stderr && >> ++ test_path_is_file .git/delete-me >> ++' >> ++ >> + test_done >> +-- >> +2.25.1 >> + >> diff --git a/meta/recipes-devtools/git/git.inc >> b/meta/recipes-devtools/git/git.inc >> index 3c4c0fd37b..5eca2e21bf 100644 >> --- a/meta/recipes-devtools/git/git.inc >> +++ b/meta/recipes-devtools/git/git.inc >> @@ -24,6 +24,10 @@ SRC_URI = >> "${KERNELORG_MIRROR}/software/scm/git/git-${PV}.tar.gz;name=tarball \ >> file://CVE-2022-41903-10.patch \ >> file://CVE-2022-41903-11.patch \ >> file://CVE-2022-41903-12.patch \ >> + file://CVE-2023-22490-1.patch \ >> + file://CVE-2023-22490-2.patch \ >> + file://CVE-2023-22490-3.patch \ >> + file://CVE-2023-23946.patch \ >> " >> S = "${WORKDIR}/git-${PV}" >> >> -- >> 2.25.1 >> > > >
-=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#179258): https://lists.openembedded.org/g/openembedded-core/message/179258 Mute This Topic: https://lists.openembedded.org/mt/97727285/21656 Group Owner: openembedded-core+ow...@lists.openembedded.org Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
