From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFE1C3ACA59 for ; Mon, 10 Aug 2026 12:01:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786363281; cv=none; b=SKEAluKp5QTmSJsx7w0o8AOuuYzp8GhhTBR5dbVepsSHdJrQrPM7suF0rtAmP0OZloqSfUWQdi0UfP2KyBYFS06tN+R0Jtzh7kCKzdXU4gyqnvAM/jQFB0glTEBOU3kyHI/MpnRY4pZaXp2bvPeRtMdNw6waIOo9t70bSFwbkns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786363281; c=relaxed/simple; bh=x7NWBGWDikXpr42Hn7KLoKEEmXfh36yZzdg73pnr++M=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=BYrH4vz/VJsd4UY5cr/crOmN8e9e+lDQiRPgUV9h2fNQr0ZD0A5vDoR4IQSY8/z7PMSU/sp68OIPL1TpiCwywfpssDsfmdVN5QsUY1FLABMehXKfAnydZuxI5pdcUsNZ4IWOFK8WN4LGKGY7F8VGpI1Ga3sVf7zTwG5GTI9KTIc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BPq8IBh+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BPq8IBh+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 294321F000E9; Mon, 10 Aug 2026 12:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786363279; bh=RD4dz2nFIhWAEvGqjpfWVkcri345CgrehiRWBkE7NB8=; h=From:To:Cc:Subject:Date:Reply-To; b=BPq8IBh+kJVu4AQL3h0pAKLI7JPyV257InwW75UqxYbFHuGWApk0nKHNr8J6AxvLx ptcOu6R7Rjq1e9fJ4LyK7HUQctK92dGx7eCVZkk4VcP3xinTtEoj8o3qQwUCdXhebf oxKJzFbmzEEIKtmASy+UdF2AfbPH6q/WmuiSoMRo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-68094: sched_ext: Preserve rq tracking across local DSQ dispatch Date: Mon, 10 Aug 2026 13:56:51 +0200 Message-ID: <2026081050-CVE-2026-68094-dd0c@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3342; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=q11rOF9lD1OY/N0axRBtkm8jG4OVYcy40Bv/pRhLwUs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmVe5rvNPBPblgYv2H91iPbZm+MOF2x+y6L2K5ry6e7z ZR/XfZevyOWhUGQiUFWTJHlyzaeo/srDil6GdqehpnDygQyhIGLUwAmkvyZYcH0qom3/rWvTM9e Whvo9bW4wfyvYSLDPP1oZqHyrebu7bOPK98zfHmvjmV/KwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: sched_ext: Preserve rq tracking across local DSQ dispatch dispatch_to_local_dsq() can run from scx_bpf_dsq_move_to_local() while ops.dispatch() has recorded the current rq. Moving a task to a local DSQ may switch to the source or destination rq before synchronously invoking ops.dequeue() through the following path: SCX_CALL_OP(dispatch, rq) ops.dispatch() scx_bpf_dsq_move_to_local() scx_flush_dispatch_buf() finish_dispatch() dispatch_to_local_dsq() scx_dispatch_enqueue() local_dsq_post_enq() call_task_dequeue() SCX_CALL_OP_TASK(dequeue, locked_rq, ...) The nested callback saves the recorded rq and restores it on return. If the rq tracking does not follow the lock switch, update_locked_rq() can trigger the following lockdep assertion while restoring an rq which is no longer held: WARNING: kernel/sched/sched.h:1641 at call_task_dequeue+0x160/0x170 Call Trace: scx_dispatch_enqueue+0x2b0/0x460 dispatch_to_local_dsq+0x138/0x230 scx_flush_dispatch_buf+0x1af/0x220 scx_bpf_dsq_move_to_local___v2+0xe2/0x1c0 bpf__sched_ext_ops_dispatch+0x4b/0xa7 do_pick_task_scx+0x3b6/0x910 __pick_next_task+0x105/0x1f0 __schedule+0x3e7/0x1980 Introduce switch_rq_lock() to update the tracking state together with each rq lock handoff. Use it in dispatch_to_local_dsq(), move_remote_task_to_local_dsq() and the in-balance paths of scx_dsq_move(), ensuring that scx_locked_rq() consistently refers to the rq whose lock is actually held throughout the lock dance. The Linux kernel CVE team has assigned CVE-2026-68094 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit 7fb39e4eb4c3db52e4707a6a1cd45362f7e803f5 and fixed in 7.1.6 with commit 97c09c9f5739b8757ee29dabb0af30069137e286 Issue introduced in 7.1 with commit 7fb39e4eb4c3db52e4707a6a1cd45362f7e803f5 and fixed in 7.2-rc4 with commit 18d62044cda7a2b40f59d910659c0b0d6accad37 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-68094 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: kernel/sched/ext/ext.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/97c09c9f5739b8757ee29dabb0af30069137e286 https://git.kernel.org/stable/c/18d62044cda7a2b40f59d910659c0b0d6accad37