On Tue, Jun 23, 2020, 1:12 PM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote: > > On 22/06/2020 20:55, Song Bao Hua (Barry Song) wrote: > > > > > >> -----Original Message----- > >> From: Dan Carpenter [mailto:dan.carpenter@xxxxxxxxxx] > >> Sent: Tuesday, June 23, 2020 6:28 AM > >> To: Colin King <colin.king@xxxxxxxxxxxxx> > >> Cc: Seth Jennings <sjenning@xxxxxxxxxx>; Dan Streetman > >> <ddstreet@xxxxxxxx>; Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>; Andrew > >> Morton <akpm@xxxxxxxxxxxxxxxxxxxx>; Song Bao Hua (Barry Song) > >> <song.bao.hua@xxxxxxxxxxxxx>; Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>; > >> linux-mm@xxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx; > >> linux-kernel@xxxxxxxxxxxxxxx > >> Subject: Re: [PATCH][next] mm/zswap: fix a couple of memory leaks and > >> rework kzalloc failure check > >> > >> On Mon, Jun 22, 2020 at 04:35:46PM +0100, Colin King wrote: > >>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx> > >>> > >>> kzalloc failures return NULL on out of memory errors, so replace the > >>> IS_ERR_OR_NULL check with the usual null pointer check. Fix two memory > >>> leaks with on acomp and acomp_ctx by ensuring these objects are free'd > >>> on the error return path. > >>> > >>> Addresses-Coverity: ("Resource leak") > >>> Fixes: d4f86abd6e35 ("mm/zswap: move to use crypto_acomp API for > >> hardware acceleration") > >>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> > > > > > > Colin, thanks for your patch. I am sorry I did the same thing with you here: > > https://lkml.org/lkml/2020/6/22/347 > > Thanks for fixing this correctly, I ran out of time yesterday to re-do > the fix. > > Colin I think this has gotten out of hand. Barry, could you please come up with a replacement for the initial patch rather than doing it incrementally? Thanks, Vitaly > > > > > > >>> --- > >>> mm/zswap.c | 16 +++++++++++----- > >>> 1 file changed, 11 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/mm/zswap.c b/mm/zswap.c > >>> index 0d914ba6b4a0..14839cbac7ff 100644 > >>> --- a/mm/zswap.c > >>> +++ b/mm/zswap.c > >>> @@ -433,23 +433,23 @@ static int zswap_cpu_comp_prepare(unsigned int > >> cpu, struct hlist_node *node) > >>> return 0; > >>> > >>> acomp_ctx = kzalloc(sizeof(*acomp_ctx), GFP_KERNEL); > >>> - if (IS_ERR_OR_NULL(acomp_ctx)) { > >>> + if (!acomp_ctx) { > >>> pr_err("Could not initialize acomp_ctx\n"); > >>> return -ENOMEM; > >>> } > >>> acomp = crypto_alloc_acomp(pool->tfm_name, 0, 0); > >>> - if (IS_ERR_OR_NULL(acomp)) { > >>> + if (!acomp) { > >> > >> This should be IS_ERR(acomp). Please preserve the error code. > >> > >>> pr_err("could not alloc crypto acomp %s : %ld\n", > >>> pool->tfm_name, PTR_ERR(acomp)); > >>> - return -ENOMEM; > >>> + goto free_acomp_ctx; > >>> } > >>> acomp_ctx->acomp = acomp; > >>> > >>> req = acomp_request_alloc(acomp_ctx->acomp); > >>> - if (IS_ERR_OR_NULL(req)) { > >>> + if (!req) { > >>> pr_err("could not alloc crypto acomp %s : %ld\n", > >>> pool->tfm_name, PTR_ERR(acomp)); > >>> - return -ENOMEM; > >>> + goto free_acomp; > >>> } > >>> acomp_ctx->req = req; > >>> > >>> @@ -462,6 +462,12 @@ static int zswap_cpu_comp_prepare(unsigned int > >> cpu, struct hlist_node *node) > >>> *per_cpu_ptr(pool->acomp_ctx, cpu) = acomp_ctx; > >>> > >>> return 0; > >>> + > >>> +free_acomp: > >>> + kfree(acomp); > >> > >> The kfree() isn't correct. It needs to be: > >> > >> crypto_free_acomp(acomp); > >> > >>> +free_acomp_ctx: > >>> + kfree(acomp_ctx); > >>> + return -ENOMEM; > >> > >> regards, > >> dan carpenter > > >
