Bug 182405

Summary: Possible race in pipeline built
Product: Red Hat Enterprise Linux 4 Reporter: Bastien Nocera <bnocera>
Component: bashAssignee: Tim Waugh <twaugh>
Status: CLOSED ERRATA QA Contact: Ben Levenson <benl>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.0CC: tao
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: RHBA-2006-0332 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-08-10 21:16:54 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 181409    

Description Bastien Nocera 2006-02-22 12:29:37 UTC
+++ This bug was initially created as a clone of Bug #181656 +++

Description of problem:
segfault while running a process intensive shell script

Version-Release number of selected component (if applicable):

How reproducible:

Here is the backtrace:
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libtermcap.so.2...done.
Loaded symbols for /lib/libtermcap.so.2
Reading symbols from /lib/libdl.so.2...
Reading symbols from /usr/lib/debug//lib/libdl-2.3.2.so.debug...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/tls/libc.so.6.1...
Reading symbols from /usr/lib/debug//lib/tls/libc-2.3.2.so.debug...done.
Loaded symbols for /lib/tls/libc.so.6.1
Reading symbols from /lib/ld-linux-ia64.so.2...
Reading symbols from /usr/lib/debug//lib/ld-2.3.2.so.debug...done.
Loaded symbols for /lib/ld-linux-ia64.so.2
#0  find_pipeline (pid=16856, running_only=1, jobp=0x60000fffffffa424)
   at jobs.c:893
893     {
(gdb) frame 0
#0  find_pipeline (pid=16856, running_only=1, jobp=0x60000fffffffa424)
   at jobs.c:893
893     {
(gdb) list
888     static PROCESS *
889     find_pipeline (pid, running_only, jobp)
890          pid_t pid;
891          int running_only;
892          int *jobp;         /* index into jobs list or NO_JOB */
893     {
894       int job;
895       register PROCESS *p;
897       /* See if this process is in the pipeline that we are building. */
(gdb) bt
#0  find_pipeline (pid=16856, running_only=1, jobp=0x60000fffffffa424)
   at jobs.c:893
#1  0x4000000000062850 in waitchld (wpid=-1, block=63080) at jobs.c:2468
#2  0x40000000000626a0 in sigchld_handler (sig=63080) at jobs.c:2398
#3  <signal handler called>
#4  waitchld (wpid=Cannot access memory at address 0xffffffffffffff70
) at jobs.c:2468
Cannot access memory at address 0xffffffffffffffe8

903           do
904             {
905               /* Return it if we found it. */
906               if (p->pid == pid)
907                 {
908                   if ((running_only && PRUNNING(p)) || (running_only == 0))
909                     return (p);
910                 }
912               p = p->next;
913             }
914           while (p != the_pipeline);

Looks like p != NULL isn't checked, which could be problematic if you get to the
end of the list without finding "the_pipeline".

-           while (p != the_pipeline);
+           while (p != NULL && p != the_pipeline);

-- Additional comment from kmori on 2006-02-21 21:38 EST --
Created an attachment (id=125001)
Fix patch backported from upstream

Comment 1 James Laska 2006-03-22 20:19:23 UTC
Test case available in bug#181656, patch available upstream.  Possible to
incorporate into RHTS.  Providing QE ACK for RHEL4-U4

Comment 4 Bob Johnson 2006-04-11 16:08:38 UTC
This issue is on Red Hat Engineering's list of planned work items 
for the upcoming Red Hat Enterprise Linux 4.4 release.  Engineering 
resources have been assigned and barring unforeseen circumstances, Red 
Hat intends to include this item in the 4.4 release.

Comment 8 Red Hat Bugzilla 2006-08-10 21:16:54 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.