Date: Thu, 11 Jan 2018 17:19:16 -0800 From: James Bottomley <jejb@...ux.vnet.ibm.com> To: Dan Williams <dan.j.williams@...el.com>, linux-kernel@...r.kernel.org Cc: linux-arch@...r.kernel.org, "Martin K. Petersen" <martin.petersen@...cle.com>, linux-scsi@...r.kernel.org, kernel-hardening@...ts.openwall.com, qla2xxx-upstream@...gic.com, tglx@...utronix.de, torvalds@...ux-foundation.org, akpm@...ux-foundation.org, Elena Reshetova <elena.reshetova@...el.com>, alan@...ux.intel.com Subject: Re: [PATCH v2 17/19] qla2xxx: prevent bounds-check bypass via speculative execution On Thu, 2018-01-11 at 16:47 -0800, Dan Williams wrote: > Static analysis reports that 'handle' may be a user controlled value > that is used as a data dependency to read 'sp' from the > 'req->outstanding_cmds' array. Greg already told you it comes from hardware, specifically the hardware response queue. If you don't believe him, I can confirm it's quite definitely all copied from the iomem where the mailbox response is, so it can't be a user controlled value (well, unless the user has some influence over the firmware of the qla2xxx controller, which probably means you have other things to worry about than speculative information leaks). I think what it actually is is a handle returned in the mailbox that's used to find other mailbox entries in different queues (the packet handle actually contains an entry in the lower 16 bits and a queue designation in the upper). Perhaps the qla2xxx people should comment on this because the code seems to check and print an error if there's a problem with the handle being too big, but we don't check the que value and use it blindly to read into the req_q_map: if handle could be wrong, couldn't que? James
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.