On Mon, Apr 16, 2018 at 8:12 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > With a hardware watchpoint, I've isolated the corruption to here: > > bfq_dispatch_request+0x2be/0x1610: > __bfq_dispatch_request at block/bfq-iosched.c:3902 > 3900 if (rq) { > 3901 inc_in_driver_start_rq: > 3902 bfqd->rq_in_driver++; > 3903 start_rq: > 3904 rq->rq_flags |= RQF_STARTED; > 3905 } FWIW, the stacktrace here (removing the ? lines) is: [ 34.311980] RIP: 0010:bfq_dispatch_request+0x2be/0x1610 [ 34.452491] blk_mq_do_dispatch_sched+0x1d9/0x260 [ 34.454561] blk_mq_sched_dispatch_requests+0x3da/0x4b0 [ 34.458789] __blk_mq_run_hw_queue+0xae/0x130 [ 34.460001] __blk_mq_delay_run_hw_queue+0x192/0x280 [ 34.460823] blk_mq_run_hw_queue+0x10b/0x1b0 [ 34.463240] blk_mq_sched_insert_request+0x3bd/0x4d0 [ 34.467342] blk_execute_rq+0xcf/0x140 [ 34.468483] sg_io+0x2f7/0x730 Can anyone tell me more about the memory allocation layout of the various variables here? It looks like struct request is a header in front of struct scsi_request? How do struct elevator_queue, struct blk_mq_ctx, and struct blk_mq_hw_ctx overlap these? Regardless, I'll check for elevator data changing too... -Kees -- Kees Cook Pixel Security