Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: unsubscribe the channel-kill event before the fence context nouveau_channel_del() tears the fence context down first and only drops the channel-kill subscription later, in the middle of the nvif object teardown: if (chan->fence) nouveau_fence(chan->cli->drm)->context_del(chan); ... nvif_object_dtor(&chan->vram); nvif_event_dtor(&chan->kill); The subscribed handler is nouveau_channel_killed(), which calls nouveau_channel_kill() and from there nouveau_fence_context_kill() on chan->fence. A kill event delivered in that window takes fctx->lock and walks fctx->pending on a fence context that context_del() has already freed. Nothing reaches this below Fermi today, because the subscription is gated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there. On Fermi and newer the window is real but narrow, since a kill has to land exactly while the channel is being destroyed. That is reason enough on its own, which is why this carries a Fixes: tag. The last patch in this series subscribes Tesla channels as well; nothing kills those today, so it does not widen the exposure now, but it is the groundwork for a recovery path that would, and the ordering is better fixed before that lands than alongside it. Drop the subscription before anything it depends on is torn down.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected ea13e5abf807ea912ce84eef6a1946b9a38c6508 before 5db663fbff7b88aeeeecaf5220e177e524165101; affected ea13e5abf807ea912ce84eef6a1946b9a38c6508 before f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e; affected ea13e5abf807ea912ce84eef6a1946b9a38c6508 before f3830fdd6930e233d727f29eee1617f7e6a0e9e5; affected ea13e5abf807ea912ce84eef6a1946b9a38c6508 before 1fef7553dc628295c1208a4f2ac2094c62886e5d; affected ea13e5abf807ea912ce84eef6a1946b9a38c6508 before 511585987d27d8cb668acebd399fc4deda23404c |
| Linux / Linux | affected 5.6; unaffected 0 before 5.6; unaffected 6.6.160 through 6.6.*; unaffected 6.12.110 through 6.12.*; unaffected 6.18.51 through 6.18.*; unaffected 7.2.5 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/5db663fbff7b88aeeeecaf5220e177e524165101
- https://git.kernel.org/stable/c/f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e
- https://git.kernel.org/stable/c/f3830fdd6930e233d727f29eee1617f7e6a0e9e5
- https://git.kernel.org/stable/c/1fef7553dc628295c1208a4f2ac2094c62886e5d
- https://git.kernel.org/stable/c/511585987d27d8cb668acebd399fc4deda23404c