From 76f8b7304d1f7c25834e2a0cc9e88c55276c47df Mon Sep 17 00:00:00 2001 From: Julie Qiu Date: Thu, 23 Jun 2022 23:18:56 +0000 Subject: [release-branch.go1.17] path/filepath: fix stack exhaustion in Glob A limit is added to the number of path separators allowed by an input to Glob, to prevent stack exhaustion issues. Thanks to Juho Nurminen of Mattermost who reported the issue. Fixes #53713 Updates #53416 Fixes CVE-2022-30632 Change-Id: I1b9fd4faa85411a05dbc91dceae1c0c8eb021f07 Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1498176 Reviewed-by: Roland Shoemaker (cherry picked from commit d182a6d1217fd0d04c9babfa9a7ccd3515435c39) Reviewed-on: https://go-review.googlesource.com/c/go/+/417073 Reviewed-by: Heschi Kreinick TryBot-Result: Gopher Robot Run-TryBot: Michael Knyszek --- src/path/filepath/match.go | 12 +++++++++++- src/path/filepath/match_test.go | 10 ++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/src/path/filepath/match.go b/src/path/filepath/match.go index c77a26952a..55ed1d75ae 100644 --- a/src/path/filepath/match.go +++ b/src/path/filepath/match.go @@ -241,6 +241,16 @@ func getEsc(chunk string) (r rune, nchunk string, err error) { // The only possible returned error is ErrBadPattern, when pattern // is malformed. func Glob(pattern string) (matches []string, err error) { + return globWithLimit(pattern, 0) +} + +func globWithLimit(pattern string, depth int) (matches []string, err error) { + // This limit is used prevent stack exhaustion issues. See CVE-2022-30632. + const pathSeparatorsLimit = 10000 + if depth == pathSeparatorsLimit { + return nil, ErrBadPattern + } + // Check pattern is well-formed. if _, err := Match(pattern, ""); err != nil { return nil, err @@ -270,7 +280,7 @@ func Glob(pattern string) (matches []string, err error) { } var m []string - m, err = Glob(dir) + m, err = globWithLimit(dir, depth+1) if err != nil { return } diff --git a/src/path/filepath/match_test.go b/src/path/filepath/match_test.go index 375c41a7e9..d6282596fe 100644 --- a/src/path/filepath/match_test.go +++ b/src/path/filepath/match_test.go @@ -155,6 +155,16 @@ func TestGlob(t *testing.T) { } } +func TestCVE202230632(t *testing.T) { + // Prior to CVE-2022-30632, this would cause a stack exhaustion given a + // large number of separators (more than 4,000,000). There is now a limit + // of 10,000. + _, err := Glob("/*" + strings.Repeat("/", 10001)) + if err != ErrBadPattern { + t.Fatalf("Glob returned err=%v, want ErrBadPattern", err) + } +} + func TestGlobError(t *testing.T) { bad := []string{`[]`, `nonexist/[]`} for _, pattern := range bad { -- cgit v1.2.3-54-g00ecf