Messages in this thread Patch in this message | | | Date | Mon, 27 Apr 2020 20:03:11 +0200 | From | Javier González <> | Subject | Re: [PATCH] nvme: prevent double free in nvme_alloc_ns() error handling |
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On 27.04.2020 14:34, Niklas Cassel wrote: >When jumping to the out_put_disk label, we will call put_disk(), which will >trigger a call to disk_release(), which calls blk_put_queue(). > >Later in the cleanup code, we do blk_cleanup_queue(), which will also call >blk_put_queue(). > >Putting the queue twice is incorrect, and will generate a KASAN splat. > >Set the disk->queue pointer to NULL, before calling put_disk(), so that the >first call to blk_put_queue() will not free the queue. > >The second call to blk_put_queue() uses another pointer to the same queue, >so this call will still free the queue. > >Fixes: 85136c010285 ("lightnvm: simplify geometry enumeration") >Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> >--- > drivers/nvme/host/core.c | 2 ++ > 1 file changed, 2 insertions(+) > >diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c >index 91c1bd659947..f2adea96b04c 100644 >--- a/drivers/nvme/host/core.c >+++ b/drivers/nvme/host/core.c >@@ -3642,6 +3642,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) > > return; > out_put_disk: >+ /* prevent double queue cleanup */ >+ ns->disk->queue = NULL; > put_disk(ns->disk); > out_unlink_ns: > mutex_lock(&ctrl->subsys->lock); >-- >2.25.3 > What about delaying the assignment of ns->disk?
diff --git i/drivers/nvme/host/core.c w/drivers/nvme/host/core.c index a4d8c90ee7cc..6da4a9ced945 100644 --- i/drivers/nvme/host/core.c +++ w/drivers/nvme/host/core.c @@ -3541,7 +3541,6 @@ static int nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) disk->queue = ns->queue; disk->flags = flags; memcpy(disk->disk_name, disk_name, DISK_NAME_LEN); - ns->disk = disk;
__nvme_revalidate_disk(disk, id);
@@ -3553,6 +3552,8 @@ static int nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) } }
+ ns->disk = disk; + down_write(&ctrl->namespaces_rwsem); list_add_tail(&ns->list, &ctrl->namespaces); up_write(&ctrl->namespaces_rwsem);
Javier
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