Eric Biggers <[email protected]> wrote: >On Tue, Sep 01, 2020 at 07:59:21AM -0400, Miaohe Lin wrote: >> mempool_alloc() may return NULL if __GFP_DIRECT_RECLAIM is not set in >> gfp_mask under memory pressure. So we should check the return value of >> mempool_alloc() against NULL before dereference. >> >> Fixes: a892c8d52c02 ("block: Inline encryption support for blk-mq") >> Signed-off-by: Miaohe Lin <[email protected]> > >It's intended that __GFP_DIRECT_RECLAIM always be set here. >Do you have an example where it isn't set here?
map_request() only pass GFP_ATOMIC to gfp_mask, though bio crypt is not used yet. >Also, if this can indeed happen, then we need to make __bio_crypt_clone() (and >bio_crypt_clone()) return a bool (or an error code) to indicate whether it >succeeded or failed. We can't just ignore the allocation failure. > >- Eric IMO, just the allocation failure is ok or we would break KABI. Many thanks.
