Re: [SSI-devel] semctl problem
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From: SAMPATHKUMAR K. K. <sam...@in...> - 2005-01-24 10:34:47
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I have fixed the code in error which caused the panic that you reported. I have also fixed the other instance which can cause panic in sys_semctl() for the client-site invocation. I have added checks in freeundos() as well so that it does not scan through the undolist without checking if the list is NULL. The patch below contains those fixes. Bharata, can you verify if this fixes your problem? Laura, can you review my fix? I plan to check-in tomorrow. Regards, - Kishore > I observed a NULL pointer dereference in semctl code. > > Call Trace: > [<c010a6df>] show_stack+0x7f/0xa0 > [<c010a88e>] show_registers+0x15e/0x210 > [<c010abb3>] die+0x93/0x120 > [<c0121336>] do_page_fault+0x2e6/0x688 > [<c010a341>] error_code+0x2d/0x38 > [<c01c0bfa>] sys_semctl+0x1da/0x350 > [<c0111d16>] sys_ipc+0xd6/0x340 > [<c0109819>] sysenter_past_esp+0x52/0x71 > > This particular problem is due to accessing undo_list without checking > its validity (ipc/sem.c:semctl_down(), line no.1055) > > There are at least a couple of other places in the same file where the > semaphore undo structures list is accessed w/o checking for its validity > first. > > Should we correct all references to undo_list to check for NULL before > accessing the list ? > > Regards, > Bharata. > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting > Tool for open source databases. Create drag-&-drop reports. Save time > by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. > Download a FREE copy at http://www.intelliview.com/go/osdn_nl > _______________________________________________ > ssic-linux-devel mailing list > ssi...@li... > https://lists.sourceforge.net/lists/listinfo/ssic-linux-devel > |