{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89803","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.767Z","datePublished":"2026-09-16T10:30:36.738Z","dateUpdated":"2026-09-16T14:38:48.708Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:38:48.708Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/nouveau: unsubscribe the channel-kill event before the fence context\n\nnouveau_channel_del() tears the fence context down first and only drops\nthe channel-kill subscription later, in the middle of the nvif object\nteardown:\n\n\tif (chan->fence)\n\t\tnouveau_fence(chan->cli->drm)->context_del(chan);\n\t...\n\tnvif_object_dtor(&chan->vram);\n\tnvif_event_dtor(&chan->kill);\n\nThe subscribed handler is nouveau_channel_killed(), which calls\nnouveau_channel_kill() and from there nouveau_fence_context_kill() on\nchan->fence. A kill event delivered in that window takes fctx->lock and\nwalks fctx->pending on a fence context that context_del() has already\nfreed.\n\nNothing reaches this below Fermi today, because the subscription is\ngated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there. On\nFermi and newer the window is real but narrow, since a kill has to land\nexactly while the channel is being destroyed. That is reason enough on\nits own, which is why this carries a Fixes: tag. The last patch in this\nseries subscribes Tesla channels as well; nothing kills those today, so\nit does not widen the exposure now, but it is the groundwork for a\nrecovery path that would, and the ordering is better fixed before that\nlands than alongside it.\n\nDrop the subscription before anything it depends on is torn down."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Reached via local DRM ioctls DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC/FREE on /dev/dri/renderD*, or by closing that fd (nouveau_drm_postclose→nouveau_abi16_chan_fini→nouveau_channel_del). Not reachable from network protocols, adjacent radios, or physical buses.\nAC:L - The attacker creates and destroys their own Fermi+ channel so the kill handler stays armed across fence teardown; they also induce the kill (illegal pushbuf/MMU fault or GSP RC during the still-subscribed nvif object dtors) and can retry, so they control both sides of the race.\nPR:L - CHANNEL_ALLOC and CHANNEL_FREE are DRM_RENDER_ALLOW with no ROOT_ONLY or capability checks. Any unprivileged local user who can open the nouveau render node (render/video group, logind ACL, Android GPU, or container) can trigger it.\nUI:N - The attacker opens their own nouveau render-node client and issues CHANNEL_ALLOC/FREE or close on that fd; no separate victim action is required.\nS:U - The use-after-free corrupts host kernel heap state (struct nouveau_fence_chan) inside the nouveau driver. Impact stays in the same kernel authority; this is not a VM escape or IOMMU/DMA isolation bypass.\nC:H - A channel-kill delivered after context_del uses chan->fence on a freed fence context, taking fctx->lock and walking fctx->pending. Reclaiming that slab enables arbitrary kernel reads as with other UAFs.\nI:H - The same UAF lets the IRQ/GSP kill path list_del and dma_fence_signal through attacker-reclaimed fence-context and pending-list pointers, enabling heap corruption, arbitrary writes, and control-flow hijack.\nA:H - Dereferencing the freed fence context from nouveau_channel_killed() (spinlock/list walk in interrupt or GSP callback) oopses or panics the kernel; the attacker can repeat CHANNEL_FREE or close to crash the system."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/nouveau/nouveau_chan.c"],"versions":[{"version":"ea13e5abf807ea912ce84eef6a1946b9a38c6508","lessThan":"f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e","status":"affected","versionType":"git"},{"version":"ea13e5abf807ea912ce84eef6a1946b9a38c6508","lessThan":"f3830fdd6930e233d727f29eee1617f7e6a0e9e5","status":"affected","versionType":"git"},{"version":"ea13e5abf807ea912ce84eef6a1946b9a38c6508","lessThan":"1fef7553dc628295c1208a4f2ac2094c62886e5d","status":"affected","versionType":"git"},{"version":"ea13e5abf807ea912ce84eef6a1946b9a38c6508","lessThan":"511585987d27d8cb668acebd399fc4deda23404c","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/nouveau/nouveau_chan.c"],"versions":[{"version":"5.6","status":"affected"},{"version":"0","lessThan":"5.6","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.51","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.3-rc2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e"},{"url":"https://git.kernel.org/stable/c/f3830fdd6930e233d727f29eee1617f7e6a0e9e5"},{"url":"https://git.kernel.org/stable/c/1fef7553dc628295c1208a4f2ac2094c62886e5d"},{"url":"https://git.kernel.org/stable/c/511585987d27d8cb668acebd399fc4deda23404c"}],"title":"drm/nouveau: unsubscribe the channel-kill event before the fence context","x_generator":{"engine":"bippy-1.2.0"}}}}