Bug #76446 [Com]: zend_variables.c:73: zend_string_destroy: Assertion `!(zval_gc_flags((str)->gc.

Edit report at https://bugs.php.net/bug.php?id=76446&edit=1 ID: 76446 Comment by: spam2 at rhsoft dot net Reported by: spam2 at rhsoft dot net Summary: zend_variables.c:73: zend_string_destroy: Assertion `!(zval_gc_flags((str)->gc. Status: Analyzed Type: Bug Package: Reproducible crash PHP Version: master-Git-2018-06-11 (Git) Block user comment: N Private report: N New Comment: sorry, no, way too much stuff on the machine nad i also don't see a way to isolate the affected code for now but that's something i will try sooner or later (currently at vacation and made the mistake "hey let's look if our codebase triggers any php-warning with the current master") Previous Comments: ------------------------------------------------------------------------ [2018-06-12 04:01:25] laruence@php.net is that possible that you could grant me a ssh access to your box to debugging it? (vid mail) that will be much helpful :) ------------------------------------------------------------------------ [2018-06-11 20:46:58] spam2 at rhsoft dot net https://git.php.net/?p=php-src.git;a=commit;h=e4e334effb9d8b6945e045fa97133f5a65d45ea6 (Remove dead code for ADD_STRING/ADD_CHAR optimization) still don't fix that * OK: cl_api->navigation_base_internal->test(0.023) zend_mm_heap corrupted php: /home/builduser/rpmbuild/BUILD/php-7.3.0/Zend/zend_variables.c:73: zend_string_destroy: Assertion `!(zval_gc_flags((str)->gc.u.type_info) & (1<<6))' failed. Program received signal SIGABRT, Aborted. 0x00007ffff68e2660 in raise () from /lib64/libc.so.6 Missing separate debuginfos, use: dnf debuginfo-install bzip2-libs-1.0.6-24.fc27.x86_64 cyrus-sasl-lib-2.1.26-34.fc27.x86_64 expat-2.2.5-1.fc27.x86_64 fontconfig-2.12.6-4.fc27.x86_64 freetype-2.8-8.fc27.x86_64 gd-2.2.5-3.fc27.x86_64 jbigkit-libs-2.1-8.fc27.x86_64 keyutils-libs-1.5.10-3.fc27.x86_64 krb5-libs-1.15.2-9.fc27.x86_64 libX11-1.6.5-4.fc27.x86_64 libXau-1.0.8-9.fc27.x86_64 libXpm-3.5.12-4.fc27.x86_64 libcom_err-1.43.5-2.fc27.x86_64 libcrypt-nss-2.26-28.fc27.x86_64 libcurl-7.55.1-12.fc27.x86_64 libgcc-7.3.1-5.fc27.x86_64 libgomp-7.3.1-5.fc27.x86_64 libicu-57.1-9.fc27.x86_64 libidn2-2.0.5-1.fc27.x86_64 libjpeg-turbo-1.5.3-1.fc27.x86_64 libnghttp2-1.31.1-1.fc27.x86_64 libpng-1.6.31-1.fc27.x86_64 libpsl-0.18.0-3.fc27.x86_64 libselinux-2.7-3.fc27.x86_64 libssh2-1.8.0-5.fc27.x86_64 libstdc++-7.3.1-5.fc27.x86_64 libtidy-5.4.0-3.fc27.x86_64 libtiff-4.0.9-10.fc27.x86_64 libunistring-0.9.10-1.fc27.x86_64 libwebp-1.0.0-1.fc27.x86_64 libxcb-1.12-5.fc27.x86_64 libxml2-2.9.7-1.fc2! 7.x86_64 libzip-1.3.2-1.fc27.x86_64 nspr-4.19.0-1.fc27.x86_64 nss-3.37.3-1.0.fc27.x86_64 nss-softokn-freebl-3.37.3-1.0.fc27.x86_64 nss-util-3.37.3-1.0.fc27.x86_64 openldap-2.4.45-4.fc27.x86_64 openssl-libs-1.1.0h-3.fc27.x86_64 pcre2-10.31-4.fc27.x86_64 systemd-libs-234-11.git5f8984e.fc27.x86_64 xz-libs-5.2.3-4.fc27.x86_64 (gdb) f 4 #4 0x000055555588a52e in zend_string_destroy (str=0x7fffe3d08b18, __zend_filename=0x5555559ce4a8 "/home/builduser/rpmbuild/BUILD/php-7.3.0/Zend/zend_vm_execute.h", __zend_lineno=12424) at /home/builduser/rpmbuild/BUILD/php-7.3.0/Zend/zend_variables.c:73 73 ZEND_ASSERT(!ZSTR_IS_INTERNED(str)); (gdb) p (char*)str->val $1 = 0x7fffe3d08b30 "&amp;openmenu=" ------------------------------------------------------------------------ [2018-06-11 13:48:58] nikic@php.net Can't say if it's *the* issue, but at least an issue is this: <?php "x{$a}y"; Crashes under opcache. Reason is that the ROPE_END is optimized away as dead code, leading to a FREE on ROPE_ADD, which is illegal. I think something similar to this would also cause your case. ------------------------------------------------------------------------ [2018-06-11 13:33:15] spam2 at rhsoft dot net there a 3 codelines in the whole codebase containing "&amp;openmenu=" from the last gdb-output which are basically "use rope instead of concat" $openstr = "&amp;openmenu={$local_row['hid']}{$addlang}"; $openstr2 = "&amp;openmenu={$openmenu}{$addlang}"; $open_part = "&amp;openmenu={$sid}{$langadd}"; Program received signal SIGABRT, Aborted. 0x00007ffff68e2660 in raise () from /lib64/libc.so.6 Missing separate debuginfos, use: dnf debuginfo-install bzip2-libs-1.0.6-24.fc27.x86_64 cyrus-sasl-lib-2.1.26-34.fc27.x86_64 expat-2.2.5-1.fc27.x86_64 fontconfig-2.12.6-4.fc27.x86_64 freetype-2.8-8.fc27.x86_64 gd-2.2.5-3.fc27.x86_64 jbigkit-libs-2.1-8.fc27.x86_64 keyutils-libs-1.5.10-3.fc27.x86_64 krb5-libs-1.15.2-9.fc27.x86_64 libX11-1.6.5-4.fc27.x86_64 libXau-1.0.8-9.fc27.x86_64 libXpm-3.5.12-4.fc27.x86_64 libcom_err-1.43.5-2.fc27.x86_64 libcrypt-nss-2.26-28.fc27.x86_64 libcurl-7.55.1-12.fc27.x86_64 libgcc-7.3.1-5.fc27.x86_64 libgomp-7.3.1-5.fc27.x86_64 libicu-57.1-9.fc27.x86_64 libidn2-2.0.5-1.fc27.x86_64 libjpeg-turbo-1.5.3-1.fc27.x86_64 libnghttp2-1.31.1-1.fc27.x86_64 libpng-1.6.31-1.fc27.x86_64 libpsl-0.18.0-3.fc27.x86_64 libselinux-2.7-3.fc27.x86_64 libssh2-1.8.0-5.fc27.x86_64 libstdc++-7.3.1-5.fc27.x86_64 libtidy-5.4.0-3.fc27.x86_64 libtiff-4.0.9-10.fc27.x86_64 libunistring-0.9.10-1.fc27.x86_64 libwebp-1.0.0-1.fc27.x86_64 libxcb-1.12-5.fc27.x86_64 libxml2-2.9.7-1.fc2! 7.x86_64 libzip-1.3.2-1.fc27.x86_64 nspr-4.19.0-1.fc27.x86_64 nss-3.37.3-1.0.fc27.x86_64 nss-softokn-freebl-3.37.3-1.0.fc27.x86_64 nss-util-3.37.3-1.0.fc27.x86_64 openldap-2.4.45-4.fc27.x86_64 openssl-libs-1.1.0h-3.fc27.x86_64 pcre2-10.31-4.fc27.x86_64 systemd-libs-234-11.git5f8984e.fc27.x86_64 xz-libs-5.2.3-4.fc27.x86_64 (gdb) f 4 #4 0x000055555588a52e in zend_string_destroy (str=0x7fffe3d08b18, __zend_filename=0x5555559ce468 "/home/builduser/rpmbuild/BUILD/php-7.3.0/Zend/zend_vm_execute.h", __zend_lineno=12424) at /home/builduser/rpmbuild/BUILD/php-7.3.0/Zend/zend_variables.c:73 73 ZEND_ASSERT(!ZSTR_IS_INTERNED(str)); (gdb) p (char*)str->val $1 = 0x7fffe3d08b30 "&amp;openmenu=" ------------------------------------------------------------------------ [2018-06-11 13:19:26] nikic@php.net Thanks for the backtrace. What is happening is that we're trying to destroy an interned string, which means that at some point we did not mark a zval as !refcounted when storing the string into it. However, the backtrace is extremely generic, so it's hard to say where the string came from. Can you please run "f 4" followed by "p (char*)str->val" when the assertion occurs? This will print the contents of the string and may help in tracking down where it is coming from (e.g. class name, method name or similar). ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=76446 -- Edit this bug report at https://bugs.php.net/bug.php?id=76446&edit=1