Coverity: nouveau_dp_irq(): Null pointer dereferences

From: coverity-bot
Date: Thu Nov 10 2022 - 11:50:49 EST


Hello!

This is an experimental semi-automated report about issues detected by
Coverity from a scan of next-20221110 as part of the linux-next scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan

You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by commits:

Mon Aug 31 19:10:08 2020 -0400
a0922278f83e ("drm/nouveau/kms/nv50-: Refactor and cleanup DP HPD handling")

Coverity reported the following:

*** CID 1527266: Null pointer dereferences (REVERSE_INULL)
drivers/gpu/drm/nouveau/nouveau_dp.c:237 in nouveau_dp_irq()
231 struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
232 struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
233 struct nv50_mstm *mstm;
234 u64 hpd = 0;
235 int ret;
236
vvv CID 1527266: Null pointer dereferences (REVERSE_INULL)
vvv Null-checking "outp" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
237 if (!outp)
238 return;
239
240 mstm = outp->dp.mstm;
241 NV_DEBUG(drm, "service %s\n", connector->name);
242

If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):

Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
Addresses-Coverity-ID: 1527266 ("Null pointer dereferences")
Fixes: a0922278f83e ("drm/nouveau/kms/nv50-: Refactor and cleanup DP HPD handling")

Thanks for your attention!

--
Coverity-bot