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| -rw-r--r-- | src/libexpr/parser.y | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 10a057062..df55986f6 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -576,10 +576,15 @@ Path resolveExprPath(Path path) { assert(path[0] == '/'); + unsigned int followCount = 0, maxFollow = 1024; + /* If `path' is a symlink, follow it. This is so that relative path references work. */ struct stat st; while (true) { + // Basic cycle/depth limit to avoid infinite loops. + if (++followCount >= maxFollow) + throw Error(format("can't resolve expression. infinite symlink recursion in path '%1%'") % path); if (lstat(path.c_str(), &st)) throw SysError(format("getting status of '%1%'") % path); if (!S_ISLNK(st.st_mode)) break; |