From ab36540bddb63139c3da9a9da5e5feacdf7bf7bf Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Wed, 5 Aug 2020 11:27:13 +0200 Subject: Explicitly validate popen mode To avoid behavior differences due to libc. --- ext/standard/file.c | 8 ++++++++ ext/standard/tests/file/popen_pclose_error.phpt | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/ext/standard/file.c b/ext/standard/file.c index 98578376b0..88ffba8102 100644 --- a/ext/standard/file.c +++ b/ext/standard/file.c @@ -930,10 +930,18 @@ PHP_FUNCTION(popen) char *z = memchr(posix_mode, 'b', mode_len); if (z) { memmove(z, z + 1, mode_len - (z - posix_mode)); + mode_len--; } } #endif + /* Musl only partially validates the mode. Manually check it to ensure consistent behavior. */ + if (mode_len != 1 || (*posix_mode != 'r' && *posix_mode != 'w')) { + php_error_docref2(NULL, command, posix_mode, E_WARNING, "Invalid mode"); + efree(posix_mode); + RETURN_FALSE; + } + fp = VCWD_POPEN(command, posix_mode); if (!fp) { php_error_docref2(NULL, command, posix_mode, E_WARNING, "%s", strerror(errno)); diff --git a/ext/standard/tests/file/popen_pclose_error.phpt b/ext/standard/tests/file/popen_pclose_error.phpt index 2f05e7788d..0713280870 100644 --- a/ext/standard/tests/file/popen_pclose_error.phpt +++ b/ext/standard/tests/file/popen_pclose_error.phpt @@ -22,7 +22,7 @@ unlink($file_path."/popen.tmp"); --EXPECTF-- *** Testing for error conditions *** -Warning: popen(abc.txt,rw): %s on line %d +Warning: popen(abc.txt,rw): Invalid mode in %s on line %d bool(false) --- Done --- -- cgit v1.2.1