When dev_dax_kmem_probe() partially succeeds (at least one range is mapped) but a subsequent range fails request_mem_region() or add_memory_driver_managed(), the probe silently continues, ultimately returning success, but with the corresponding range resource NULL'ed out.
dev_dax_kmem_remove() iterates over all dax_device ranges regardless of if the underlying resource exists. When remove_memory() is called later, it returns 0 because the memory was never added which causes dev_dax_kmem_remove() to incorrectly assume the (nonexistent) resource can be removed and attempts cleanup on a NULL pointer. Fix this by skipping these ranges altogether, noting that these cases are considered success, such that the cleanup is still reached when all actually-added ranges are successfully removed. Reviewed-by: Ben Cheatham <[email protected]> Fixes: 60e93dc097f7 ("device-dax: add dis-contiguous resource support") Signed-off-by: Davidlohr Bueso <[email protected]> --- Changes from v1: reword some of the changelog (Ben) drivers/dax/kmem.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index c036e4d0b610..edd62e68ffb7 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -227,6 +227,12 @@ static void dev_dax_kmem_remove(struct dev_dax *dev_dax) if (rc) continue; + /* range was never added during probe */ + if (!data->res[i]) { + success++; + continue; + } + rc = remove_memory(range.start, range_len(&range)); if (rc == 0) { remove_resource(data->res[i]); -- 2.39.5
