From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792758887; b=SghLusNxvqwTvYl/zGh8Ak8gPfUMi+tt27ZnzYU4DJH0enVjwhRbs+0pIrFHyCKUWM9D gVMv4VOeE71X8YHXwM9eZE6q4Xy+gK52VaejMU/LOe4EXng6cFEkjp3IbYxQkVBo/eF5h 6BLIn/pENkCRVCfAyHT7iFRYnn5CajUK5zK7J91FSmBO2pRuGPPpdyL1and0YrJOYtQXC qMBL605tuM4O25TDHrXc/bEty5lxhnd3m7PycycapPpHXv7q6wmEI3EcGc9Y7fm1XcMcI k/j4qk/yAfIECDc8ZIfzLneHC3GAGJydUrPWX6Dq+ru62nfaB+iJb05bcNFLie++XNQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792758887; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: Reply-To:MIME-Version:Lines:X-Developer-Signature:X-Developer-Key: Content-Transfer-Encoding; bh=01E3bNIEtVhSQOQ6fKRcSZfXJXgT3ENuUQkykA2lKHA=; b=ynBvXkpJ2qABgwjuEhVb/sge2sC2VYEFtaI05kCcltgayh9kX4D1r2oK7jr04NuSsDfR OSz9b1ue3Ft3YKBm5JtgC9UtiRLuWBYkwgG0QjoZQ4/pPUQ6e8/UkLV/gDi3MdYBDfuRH qRHYdqDSyi1DWlN7w/hwt9Yo0vB7afGKSrSvLbleCCX+P8q4TK4C69OIh/11zNKnpQjzA STHLlTNorrit3Kk6CJKbeg38FpAl+NXSJQ7J5i0Eao/I4e7i0ci/G+NmYWn9pQyD1+hGo X+0D4LGPQCCGHVZv97gpMDodYp9DGMykjCobEGFoDKzMAyvKZ5xH9W7Fpai+C818ROA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=glSZCdbW; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82B4F606A31B for ; Fri, 23 Oct 2026 12:34:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=glSZCdbW Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D4D61F01828; Fri, 23 Oct 2026 12:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792758887; bh=01E3bNIEtVhSQOQ6fKRcSZfXJXgT3ENuUQkykA2lKHA=; h=From:To:Cc:Subject:Date:Reply-To; b=glSZCdbWPHqBJooHXbkxLArzjmPscVW8tXBvJTyJFrDpCa34liK0T17HRMXoRtXSy gLoEW/3BSGWqrqBoDXbhFGD4EHfIKgedMRqyciW92INonnuE9oOGukschrG82gkMt1 D4kve2IoX+SBEuJBBSpgxD0bw1zH3wblZYf/PEtQ= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-99007: drm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN Date: Fri, 23 Oct 2026 14:20:09 +0200 Message-ID: <2026102319-CVE-2026-99007-87cb@gregkh> X-Mailer: git-send-email 2.56.0 Reply-To: , X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3812; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=T/uy70rWof4f/qH+VuzZMGZpkX1sFEw/eJ66yxrJhQQ=; b=owGbwMvMwCRo6H6F97bub03G02pJDFm3A45zXwybbOq4qHNZzfkcBy+PDvnEt7yZ8zIPpvHoF m9QcHDriGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgIkwhzAsWK3zYs7NNalT1y6X sTqkeu7NpYneCgxzBazKFzzh9OGeNbt4RY7zZFeBeU8lAA== 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: drm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN __drm_fb_helper_initial_config_and_unlock() calls drm_client_modeset_probe() first, which already fills in each mode_set->mode/num_connectors for every connected output, and only afterwards calls drm_fb_helper_single_fb_probe() to create fb_helper->fb and wire it into those mode_sets via drm_setup_crtcs_fb(). If drm_fb_helper_single_fb_probe() fails with anything other than -EAGAIN (e.g. dev->driver->fbdev_probe() itself fails), the function bails out before drm_setup_crtcs_fb() runs and before setting fb_helper->deferred_setup. The client is left with mode_sets that have a mode and connectors but mode_set->fb == NULL, and nothing marks this fb_helper as needing a retry. __drm_fb_helper_restore_fbdev_mode_unlocked() only skips committing when fb_helper->deferred_setup is set, so a later .restore() call (drm_lastclose() on process exit, in this report) commits the stale mode_set through drm_client_modeset_commit() -> drm_client_modeset_commit_atomic() -> __drm_atomic_helper_set_config(), which hits WARN_ON(!set->fb). Mark fb_helper->deferred_setup on any drm_fb_helper_single_fb_probe() failure, not just -EAGAIN, so restore keeps skipping the commit until a later hotplug event successfully re-probes and re-populates mode_set->fb. The real error code is still returned to the caller unchanged. The Linux kernel CVE team has assigned CVE-2026-99007 to this issue. Affected and fixed versions =========================== Issue introduced in 4.14 with commit ca91a2758fcef6635626993557dd51cfbb6dd134 and fixed in 6.6.160 with commit 4a2006c675758f0c765b36fec6b49d17e89159cf Issue introduced in 4.14 with commit ca91a2758fcef6635626993557dd51cfbb6dd134 and fixed in 6.12.113 with commit 3b303696f61461b3569019d7fcac6a646652b2b4 Issue introduced in 4.14 with commit ca91a2758fcef6635626993557dd51cfbb6dd134 and fixed in 6.18.57 with commit 4e7b508c7c60dec7a86b7eb2a1b7e6d174afa457 Issue introduced in 4.14 with commit ca91a2758fcef6635626993557dd51cfbb6dd134 and fixed in 7.2.11 with commit d510ed273854177f0a3ed330145858b2fe667f81 Issue introduced in 4.14 with commit ca91a2758fcef6635626993557dd51cfbb6dd134 and fixed in 7.3 with commit 755c94d178b7e972bb766199d34e4ba4f63a89eb 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-2026-99007 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: drivers/gpu/drm/drm_fb_helper.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/4a2006c675758f0c765b36fec6b49d17e89159cf https://git.kernel.org/stable/c/3b303696f61461b3569019d7fcac6a646652b2b4 https://git.kernel.org/stable/c/4e7b508c7c60dec7a86b7eb2a1b7e6d174afa457 https://git.kernel.org/stable/c/d510ed273854177f0a3ed330145858b2fe667f81 https://git.kernel.org/stable/c/755c94d178b7e972bb766199d34e4ba4f63a89eb