• Bart Van Assche's avatar
    block: Avoid that blk_exit_rl() triggers a use-after-free · b425e504
    Bart Van Assche authored
    Since the introduction of .init_rq_fn() and .exit_rq_fn() it is
    essential that the memory allocated for struct request_queue
    stays around until all blk_exit_rl() calls have finished. Hence
    make blk_init_rl() take a reference on struct request_queue.
    This patch fixes the following crash:
    general protection fault: 0000 [#2] SMP
    CPU: 3 PID: 28 Comm: ksoftirqd/3 Tainted: G      D         4.12.0-rc2-dbg+ #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
    task: ffff88013a108040 task.stack: ffffc9000071c000
    RIP: 0010:free_request_size+0x1a/0x30
    RSP: 0018:ffffc9000071fd38 EFLAGS: 00010202
    RAX: 6b6b6b6b6b6b6b6b RBX: ffff880067362a88 RCX: 0000000000000003
    RDX: ffff880067464178 RSI: ffff880067362a88 RDI: ffff880135ea4418
    RBP: ffffc9000071fd40 R08: 0000000000000000 R09: 0000000100180009
    R10: ffffc9000071fd38 R11: ffffffff81110800 R12: ffff88006752d3d8
    R13: ffff88006752d3d8 R14: ffff88013a108040 R15: 000000000000000a
    FS:  0000000000000000(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fa8ec1edb00 CR3: 0000000138ee8000 CR4: 00000000001406e0
    Call Trace:
    Fixes: commit e9c787e6 ("scsi: allocate scsi_cmnd structures as part of struct request")
    Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
    Acked-by: default avatarTejun Heo <tj@kernel.org>
    Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Cc: Jan Kara <jack@suse.cz>
    Cc: <stable@vger.kernel.org> # v4.11+
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
blk-sysfs.c 23.1 KB