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    Subject[PATCH 4.19 47/97] nvme-multipath: Fix memory leak with ana_log_buf
    Date
    From: Logan Gunthorpe <logang@deltatee.com>

    commit 3b7830904e17202524bad1974505a9bfc718d31f upstream.

    kmemleak reports a memory leak with the ana_log_buf allocated by
    nvme_mpath_init():

    unreferenced object 0xffff888120e94000 (size 8208):
    comm "nvme", pid 6884, jiffies 4295020435 (age 78786.312s)
    hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
    01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
    backtrace:
    [<00000000e2360188>] kmalloc_order+0x97/0xc0
    [<0000000079b18dd4>] kmalloc_order_trace+0x24/0x100
    [<00000000f50c0406>] __kmalloc+0x24c/0x2d0
    [<00000000f31a10b9>] nvme_mpath_init+0x23c/0x2b0
    [<000000005802589e>] nvme_init_identify+0x75f/0x1600
    [<0000000058ef911b>] nvme_loop_configure_admin_queue+0x26d/0x280
    [<00000000673774b9>] nvme_loop_create_ctrl+0x2a7/0x710
    [<00000000f1c7a233>] nvmf_dev_write+0xc66/0x10b9
    [<000000004199f8d0>] __vfs_write+0x50/0xa0
    [<0000000065466fef>] vfs_write+0xf3/0x280
    [<00000000b0db9a8b>] ksys_write+0xc6/0x160
    [<0000000082156b91>] __x64_sys_write+0x43/0x50
    [<00000000c34fbb6d>] do_syscall_64+0x77/0x2f0
    [<00000000bbc574c9>] entry_SYSCALL_64_after_hwframe+0x49/0xbe

    nvme_mpath_init() is called by nvme_init_identify() which is called in
    multiple places (nvme_reset_work(), nvme_passthru_end(), etc). This
    means nvme_mpath_init() may be called multiple times before
    nvme_mpath_uninit() (which is only called on nvme_free_ctrl()).

    When nvme_mpath_init() is called multiple times, it overwrites the
    ana_log_buf pointer with a new allocation, thus leaking the previous
    allocation.

    To fix this, free ana_log_buf before allocating a new one.

    Fixes: 0d0b660f214dc490 ("nvme: add ANA support")
    Cc: <stable@vger.kernel.org>
    Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
    Reviewed-by: Christoph Hellwig <hch@lst.de>
    Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
    Signed-off-by: Keith Busch <kbusch@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/nvme/host/multipath.c | 1 +
    1 file changed, 1 insertion(+)

    --- a/drivers/nvme/host/multipath.c
    +++ b/drivers/nvme/host/multipath.c
    @@ -569,6 +569,7 @@ int nvme_mpath_init(struct nvme_ctrl *ct
    }

    INIT_WORK(&ctrl->ana_work, nvme_ana_work);
    + kfree(ctrl->ana_log_buf);
    ctrl->ana_log_buf = kmalloc(ctrl->ana_log_size, GFP_KERNEL);
    if (!ctrl->ana_log_buf) {
    error = -ENOMEM;

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