Repository navigation
Segfaults with PHP 7.4.27 fpm and mysqlnd driver #7877
Description
Description
We started to get a lot of segfaults recently using PHP 7.4.27 FPM. Every segfault is related to the mysqlnd extension and it seems that something goes wrong while executing a PDO statement.
I could provide the full backtrace if needed. I just need some secure place to upload it.
To Reproduce
I tried to reproduce the error in a minimal example using similar queries, but that did not trigger the problem.
Expected behavior
A call to PDOStatement->execute should not run into a segfault.
Package(s) (please complete the following information):
php7.4-fpm:
Installed: 7.4.27-1+ubuntu20.04.1+deb.sury.org+1
Candidate: 7.4.27-1+ubuntu20.04.1+deb.sury.org+1
Version table:
*** 7.4.27-1+ubuntu20.04.1+deb.sury.org+1 500
500 http://ppa.launchpad.net/ondrej/php/ubuntu focal/main amd64 Packages
100 /var/lib/dpkg/status
7.4.3-4ubuntu2.8 500
500 http://de.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
500 http://mirror.hetzner.de/ubuntu/packages focal-updates/universe amd64 Packages
7.4.3-4ubuntu2.7 500
500 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages
500 http://mirror.hetzner.de/ubuntu/packages focal-security/universe amd64 Packages
7.4.3-4ubuntu1 500
500 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
500 http://mirror.hetzner.de/ubuntu/packages focal/universe amd64 Packages
Additional context
Backtrace using gdb:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f3157ed21bb in ?? () from /usr/lib/php/20190902/mysqlnd.so
(gdb) bt
#0 0x00007f3157ed21bb in ?? () from /usr/lib/php/20190902/mysqlnd.so
#1 0x00007f3157ed3708 in ?? () from /usr/lib/php/20190902/mysqlnd.so
#2 0x00007f3157ede815 in ?? () from /usr/lib/php/20190902/mysqlnd.so
#3 0x00007f3157edaf6d in ?? () from /usr/lib/php/20190902/mysqlnd.so
#4 0x00007f3157eddd8d in ?? () from /usr/lib/php/20190902/mysqlnd.so
#5 0x00007f3157eccaaf in ?? () from /usr/lib/php/20190902/mysqlnd.so
#6 0x00007f3154b20bc6 in ?? () from /usr/lib/php/20190902/pdo_mysql.so
#7 0x00007f3157eab191 in ?? () from /usr/lib/php/20190902/pdo.so
#8 0x000055775c2aafe5 in ZEND_DO_FCALL_SPEC_RETVAL_USED_HANDLER () at ./Zend/zend_vm_execute.h:1730
#9 execute_ex (ex=0x7ffcfb317090) at ./Zend/zend_vm_execute.h:53525
#10 0x000055775c213f6f in zend_call_function (fci=fci@entry=0x7ffcfb317b80, fci_cache=0x7f31452277c8, fci_cache@entry=0x7ffcfb317b60)
at ./Zend/zend_execute_API.c:820
#11 0x000055775c23ee5c in zend_call_method (object=0x7f30e56e3430, obj_ce=<optimized out>, fn_proxy=0x7f3142c29cd0,
function_name=0x55775c2e5bdd "getiterator", function_name_len=<optimized out>, retval_ptr=0x7ffcfb317c60, param_count=0, arg1=0x0, arg2=0x0)
at ./Zend/zend_interfaces.c:103
#12 0x000055775c23f623 in zend_user_it_new_iterator (ce=ce@entry=0x7f3142c21040, object=object@entry=0x7f30e56e3430, retval=retval@entry=0x7ffcfb317c60)
at ./Zend/zend_interfaces.c:127
PHP Version
PHP 7.4.27
Operating System
Ubuntu 20.04
Activity
derickr commentedon Jan 3, 2022
niclashoyer commentedon Jan 3, 2022
@derickr I can't say this for sure, as we recently upgraded to 7.4.27 after we got segfaults, but I don't have any dumps for 7.4.26
kamil-tekiela commentedon Jan 3, 2022
Do you think this could be a security issue? If not, then you can provide more details in this GH issue.
It would be useful to have a script to reproduce the problem.
cmb69 commentedon Jan 3, 2022
Note that PHP 7.4 is no longer actively supported, so won't receive bug fixes (opposed to security fixes). Since this doesn't look like a security issue, could you please check whether this affects any of the actively supported versions?
niclashoyer commentedon Jan 3, 2022
@cmb69 I see, we will try to reproduce on 8.x
niclashoyer commentedon Jan 4, 2022
I'll close this for now, it might take some time until we switch to 8.x.