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.
Created attachment 149251 [details] crash "log" command output at kernel panic
Created attachment 149253 [details] crash "log" command output at system hang
Created attachment 149254 [details] flock patch
*** Bug 230978 has been marked as a duplicate of this bug. ***
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.
*** This bug has been marked as a duplicate of 234367 ***