DEBIAN-CVE-2025-40329

In the Linux kernel, the following vulnerability has been resolved: drm/sched: Fix deadlock in drmschedentitykilljobscb The Mesa issue referenced below pointed out a possible deadlock: [ 1231.611031] Possible interrupt unsafe locking scenario: [ 1231.611033] CPU0 CPU1 [ 1231.611034] ---- ---- [ 1231.611035] lock(&xa->xalock#17); [ 1231.611038] localirqdisable(); [ 1231.611039] lock(&fence->lock); [ 1231.611041] lock(&xa->xalock#17); [ 1231.611044] <Interrupt> [ 1231.611045] lock(&fence->lock); [ 1231.611047] * DEADLOCK * In this example, CPU0 would be any function accessing job->dependencies through the xa* functions that don't disable interrupts (eg: drmschedjobadddependency(), drmschedentitykilljobscb()). CPU1 is executing drmschedentitykilljobscb() as a fence signalling callback so in an interrupt context. It will deadlock when trying to grab the xalock which is already held by CPU0. Replacing all xa* usage by their xa*irq counterparts would fix this issue, but Christian pointed out another issue: dmafencesignal takes fence.lock and so does dmafenceaddcallback. dmafencesignal() // locks f1.lock -> drmschedentitykilljobscb() -> foreach dependencies -> dmafenceaddcallback() // locks f2.lock This will deadlock if f1 and f2 share the same spinlock. To fix both issues, the code iterating on dependencies and re-arming them is moved out to drmschedentitykilljobswork(). [phasta: commit message nits]