diff --git a/Documentation/RelNotes/2.30.8.txt b/Documentation/RelNotes/2.30.8.txt new file mode 100644 index 0000000000..38c23e0345 --- /dev/null +++ b/Documentation/RelNotes/2.30.8.txt @@ -0,0 +1,52 @@ +Git v2.30.8 Release Notes +========================= + +This release addresses the security issues CVE-2023-22490 and +CVE-2023-23946. + + +Fixes since v2.30.7 +------------------- + + * CVE-2023-22490: + + Using a specially-crafted repository, Git can be tricked into using + its local clone optimization even when using a non-local transport. + Though Git will abort local clones whose source $GIT_DIR/objects + directory contains symbolic links (c.f., CVE-2022-39253), the objects + directory itself may still be a symbolic link. + + These two may be combined to include arbitrary files based on known + paths on the victim's filesystem within the malicious repository's + working copy, allowing for data exfiltration in a similar manner as + CVE-2022-39253. + + * CVE-2023-23946: + + By feeding a crafted input to "git apply", a path outside the + working tree can be overwritten as the user who is running "git + apply". + + * A mismatched type in `attr.c::read_attr_from_index()` which could + cause Git to errantly reject attributes on Windows and 32-bit Linux + has been corrected. + +Credit for finding CVE-2023-22490 goes to yvvdwf, and the fix was +developed by Taylor Blau, with additional help from others on the +Git security mailing list. + +Credit for finding CVE-2023-23946 goes to Joern Schneeweisz, and the +fix was developed by Patrick Steinhardt. + + +Johannes Schindelin (1): + attr: adjust a mismatched data type + +Patrick Steinhardt (1): + apply: fix writing behind newly created symbolic links + +Taylor Blau (3): + t5619: demonstrate clone_local() with ambiguous transport + clone: delay picking a transport until after get_repo_path() + dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS + diff --git a/Documentation/RelNotes/2.31.7.txt b/Documentation/RelNotes/2.31.7.txt new file mode 100644 index 0000000000..dd44d5bc62 --- /dev/null +++ b/Documentation/RelNotes/2.31.7.txt @@ -0,0 +1,6 @@ +Git v2.31.7 Release Notes +========================= + +This release merges up the fixes that appear in v2.30.8 to +address the security issues CVE-2023-22490 and CVE-2023-23946; +see the release notes for that version for details. diff --git a/apply.c b/apply.c index 853d3ed385..f562f799d6 100644 --- a/apply.c +++ b/apply.c @@ -4402,6 +4402,33 @@ 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/builtin/clone.c b/builtin/clone.c index cdf9208d45..97de324e54 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -1220,10 +1220,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix) refspec_appendf(&remote->fetch, "+%s*:%s*", src_ref_prefix, branch_top.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) { @@ -1245,6 +1241,10 @@ 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/dir-iterator.c b/dir-iterator.c index b17e9f970a..3764dd81a1 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 08229157c6..e3b6ff2800 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 92910e4e6c..c826f60f6d 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/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh index 872fcda6cb..1acb7b2582 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 diff --git a/t/t5604-clone-reference.sh b/t/t5604-clone-reference.sh index 6fb7a6e7a0..574d8c4147 100755 --- a/t/t5604-clone-reference.sh +++ b/t/t5604-clone-reference.sh @@ -344,4 +344,20 @@ 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 "$(pwd)/sensitive" ./malicious/.git/objects && + + test_must_fail git clone --local malicious clone 2>err && + + test_path_is_missing clone && + grep "failed to start iterator over" err +' + test_done diff --git a/t/t5619-clone-local-ambiguous-transport.sh b/t/t5619-clone-local-ambiguous-transport.sh new file mode 100755 index 0000000000..cce62bf78d --- /dev/null +++ b/t/t5619-clone-local-ambiguous-transport.sh @@ -0,0 +1,70 @@ +#!/bin/sh + +test_description='test local clone with ambiguous transport' + +. ./test-lib.sh +. "$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 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