Bug 230976 - A timing window that causes double freeing file_lock entry
A timing window that causes double freeing file_lock entry
Status: CLOSED DUPLICATE of bug 234367
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel (Show other bugs)
4.4
All Linux
medium Severity high
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Assigned To: Dave Anderson
Brian Brock
:
: 230978 (view as bug list)
Depends On:
Blocks:
  Show dependency treegraph
 
Reported: 2007-03-05 04:16 EST by Tadashi Iwashita
Modified: 2007-11-16 20:14 EST (History)
3 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
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Last Closed: 2007-05-16 17:30:28 EDT
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RHEL 7.3 requirements from Atomic Host:
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Attachments (Terms of Use)
crash "log" command output at kernel panic (24.62 KB, text/plain)
2007-03-05 04:16 EST, Tadashi Iwashita
no flags Details
crash "log" command output at system hang (22.90 KB, text/plain)
2007-03-05 04:20 EST, Tadashi Iwashita
no flags Details
flock patch (1.92 KB, patch)
2007-03-05 04:21 EST, Tadashi Iwashita
no flags Details | Diff

  None (edit)
Description Tadashi Iwashita 2007-03-05 04:16:48 EST
Description of problem:
Encountered (1) a kernel panic and (2) a system hang on web server running 
with mod_jk when ApacheBench tool from another node started. 

(1) kernel panic
Panic at line 168 on fs/lock.c displaying "Attempting to free lock on active 
lock list" due to a bad fl_link. Please see the the output of crash "log" 
command (attached as kernel_panic.txt).
(2) system hang
Loop at line 737 on fs/lock.c with holding lock_kernel due to a self-linked 
fl_next. Please see the output of crash "log" command (attached as 
system_hang.txt).

Version-Release number of selected component (if applicable):
kernel-2.6.9-42.ELsmp
mod_jk-1.2.20

How reproducible:
Always

Steps to Reproduce:
Just run ApacheBench tool for SMP web server.
  
Additional info:
With some kinds of kernel trapper and by looking at the kernel dump, it is 
most likely that the problem was caused by double freeing file_lock entry at a 
timing window. Checked LKML, then found http://lkml.org/lkml/2006/5/17/261 and 
the patch for this issue has already been applied to upper version.

ApacheBench worked normally with the patch (attached flock.patch), so please 
consider applying this patch to the next stability updates or as a security 
update. Thanks.
Comment 1 Tadashi Iwashita 2007-03-05 04:16:48 EST
Created attachment 149251 [details]
crash "log" command output at kernel panic
Comment 2 Tadashi Iwashita 2007-03-05 04:20:18 EST
Created attachment 149253 [details]
crash "log" command output at system hang
Comment 3 Tadashi Iwashita 2007-03-05 04:21:43 EST
Created attachment 149254 [details]
flock patch
Comment 4 Linda Wang 2007-03-09 11:37:34 EST
*** Bug 230978 has been marked as a duplicate of this bug. ***
Comment 5 RHEL Product and Program Management 2007-05-09 02:58:34 EDT
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.
Comment 6 Ernie Petrides 2007-05-16 17:30:28 EDT

*** This bug has been marked as a duplicate of 234367 ***

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