drm/nouveau: unsubscribe the channel-kill event before the fence context
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 6.12.110, 6.18.51, 7.2.5
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From ea13e5abf807ea912ce84eef6a1946b9a38c6508 · fixed in 5db663fbff7b88aeeeecaf5220e177e524165101; From ea13e5abf807ea912ce84eef6a1946b9a38c6508 · fixed in f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e; From ea13e5abf807ea912ce84eef6a1946b9a38c6508 · fixed in f3830fdd6930e233d727f29eee1617f7e6a0e9e5; From ea13e5abf807ea912ce84eef6a1946b9a38c6508 · fixed in 1fef7553dc628295c1208a4f2ac2094c62886e5d; From ea13e5abf807ea912ce84eef6a1946b9a38c6508 · fixed in 511585987d27d8cb668acebd399fc4deda23404c
- Linux Linux
5.6
- KernelLinux
From 5.6.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5