Bug #78796 [Opn->Dup]: Zend lex_scan BUS error

Edit report at https://bugs.php.net/bug.php?id=78796&edit=1 ID: 78796 Updated by: nikic@php.net Reported by: tannerp at supermicro dot com Summary: Zend lex_scan BUS error -Status: Open +Status: Duplicate Type: Bug Package: Apache2 related Operating System: CentOS 7.6.1810 PHP Version: 7.2.24 Block user comment: N Private report: N New Comment: Very likely duplicate of bug #52752. This is fixed in PHP 7.4 in the sense that it will no longer cause a bus error, but the root cause is that you are concurrently modifying a file and trying to include it at the same time. Possibly you have some cache based on writing PHP files? This should be avoided (e.g. by using flock) as you may end up including a partially modified file. Previous Comments: ------------------------------------------------------------------------ [2019-11-08 20:51:34] tannerp at supermicro dot com Description: ------------ The Setup is as follows: Host environment is Kubernetes Host supplimentary tool is HAProxy for health checking and load balancing. a container with a derived image of CentOS 7.6.1810 the use of the Remi-repository for PHP 7.2.24 I am encountering an issue where apache 2 will crash with a BUS error "[core:notice] [pid 13] AH00051: child pid 108 exit signal Bus error (7)" These happen about 10 times per day. We can increase the frequency of the error if we run the http health check from HAProxy which does a basic http connection to the server. Everything said web server still appears to be running fine, but we have it only open for internal use so its hard to gauge the actual impact of these crashes. I ran a gdb on a few of the core dumps. The error differs but the bug always happens somewhere with a lex_scan call from the Zend library. If any additional info is needed please let me know. I figured I'd report this issue for visibility. Regards, Tanner Posada Test script: --------------- No easy reproduce code. Actual result: -------------- Sample Backtrace: #0 lex_scan (zendlval=zendlval@entry=0x7ffcfe6dedc0) at Zend/zend_language_scanner.c:7565 7565 if (yych == '<') goto yy801; (gdb) bt full #0 lex_scan (zendlval=zendlval@entry=0x7ffcfe6dedc0) at Zend/zend_language_scanner.c:7565 yych = <error reading variable yych (Cannot access memory at address 0x7f434cdf1000)> yyaccept = 0 start_line = 1 #1 0x00007f4348218234 in zendlex (elem=elem@entry=0x7ffcfe6dee90) at /usr/src/debug/php-7.2.24/Zend/zend_compile.c:1728 zv = {value = {lval = 139926675799264, dval = 6.9132963449182091e-310, counted = 0x7f4337ce3ce0, str = 0x7f4337ce3ce0, arr = 0x7f4337ce3ce0, obj = 0x7f4337ce3ce0, res = 0x7f4337ce3ce0, ref = 0x7f4337ce3ce0, ast = 0x7f4337ce3ce0, zv = 0x7f4337ce3ce0, ptr = 0x7f4337ce3ce0, ce = 0x7f4337ce3ce0, func = 0x7f4337ce3ce0, ww = {w1 = 936262880, w2 = 32579}}, u1 = {v = {type = 0 '\000', type_flags = 0 '\000', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 0}, u2 = {next = 4003537210, cache_slot = 4003537210, lineno = 4003537210, num_args = 4003537210, fe_pos = 4003537210, fe_iter_idx = 4003537210, access_flags = 4003537210, property_guard = 4003537210, extra = 4003537210}} retval = <optimized out> start_lineno = 1 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=78796&edit=1