On Mon, Sep 20, 2021 at 8:17 PM Tim Gardner <[email protected]> wrote: > > Coverity complains of a resource leak in ga102_chan_new(): > > CID 119637 (#7 of 7): Resource leak (RESOURCE_LEAK) > 13. leaked_storage: Variable chan going out of scope leaks the storage it > points to. > 190 return ret; > > Fix this by freeing 'chan' in the error path. >
yeah, this is actually a false positive. I ran your patch through kasan and got a use-after-free as we deallocate the passed in pointer after calling the function pointer to the new function. One might argue that the programming style isn't the best and we should be explicit about freeing memory though. > Cc: Ben Skeggs <[email protected]> > Cc: David Airlie <[email protected]> > Cc: Daniel Vetter <[email protected]> > Cc: Karol Herbst <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Signed-off-by: Tim Gardner <[email protected]> > --- > .../gpu/drm/nouveau/nvkm/engine/fifo/ga102.c | 20 ++++++++++++------- > 1 file changed, 13 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c > b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c > index f897bef13acf..4dbdfb53e65f 100644 > --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c > +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c > @@ -175,19 +175,21 @@ ga102_chan_new(struct nvkm_device *device, > } > } > > - if (!chan->ctrl.runl) > - return -ENODEV; > + if (!chan->ctrl.runl) { > + ret = -ENODEV; > + goto free_chan; > + } > > chan->ctrl.chan = nvkm_rd32(device, chan->ctrl.runl + 0x004) & > 0xfffffff0; > args->token = nvkm_rd32(device, chan->ctrl.runl + 0x008) & 0xffff0000; > > ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, > true, &chan->mthd); > if (ret) > - return ret; > + goto free_chan; > > ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, > true, &chan->inst); > if (ret) > - return ret; > + goto free_chan; > > nvkm_kmap(chan->inst); > nvkm_wo32(chan->inst, 0x010, 0x0000face); > @@ -209,11 +211,11 @@ ga102_chan_new(struct nvkm_device *device, > > ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, > true, &chan->user); > if (ret) > - return ret; > + goto free_chan; > > ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, > true, &chan->runl); > if (ret) > - return ret; > + goto free_chan; > > nvkm_kmap(chan->runl); > nvkm_wo32(chan->runl, 0x00, 0x80030001); > @@ -228,10 +230,14 @@ ga102_chan_new(struct nvkm_device *device, > > ret = nvkm_vmm_join(vmm, chan->inst); > if (ret) > - return ret; > + goto free_chan; > > chan->vmm = nvkm_vmm_ref(vmm); > return 0; > + > +free_chan: > + kfree(chan); > + return ret; > } > > static const struct nvkm_device_oclass > -- > 2.33.0 >
