drm/nouveau/clk: fix list cursor use after loop in nvkm_clk_ustate_update

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If list_for_each_entry() exits without hitting a break then "pstate" is
not a valid pstate pointer.  Introduce a "found" variable instead.

The check is reachable from userspace: nvkm_clk_ustate_update() takes the
pstate id straight from the 'pstate' debugfs file, so requesting an id
that is not in clk->states - or any id at all when the perf tables are
broken and the list is empty - makes the pstate->pstate != req test
dereference the list head cast to a struct nvkm_pstate, which is an
out-of-bounds read.

Fixes: 7c85652206 ("drm/nouveau/clk: implement power state and engine clock control in core")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[Francesco: rebased on drm-misc-next, expanded the commit message]
Signed-off-by: Francesco Magazzu <postadelmaga@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260918131620.405133-2-postadelmaga@gmail.com

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Dan Carpenter 2026-09-18 15:16:17 +02:00 • committed by Lyude Paul

parent fefd9480ec

commit aff09d9e37

1 changed files with 5 additions and 2 deletions

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drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c

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