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=1794047660; b=0FqiqxmbnkI3ku3RLuKLG99UmXNNDqJwvcwkTdzX65zZDECSWcJ5EdgVoETjRrU3POHJ ytsEmmaU4G/57YWKOatHwjnaU6xLGyCk0LXlWzVYo3hu14Y9wz6QzZOwdvTO5cjPPx6vn dNnVBj32CKNq9x5iHMz9M/dlaJH7ref7PcQkcoDiwxliSnofeNHJ7hdbkF723DJ0HKe+z I0Y2b0QfPpDF/zDq9YtoryCKVj3vVgG1sqfU631K7nNwPod4+BjuvFzh+sviRs/7rphb5 VWlPuZkXQZXMNYoUklnIMiiwlBricGdeJTZcnb0n7dEyJH6tmh9jUtOOyM1OpUNmTeA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047660; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=K7AXBMAt7B8q9vhp6U935PfPsBA33vBmhx7DUqAXU+4=; b=Rj1TrGCtBcNF9m0ZZpgw5py8zhg0mSEayXxL/at4WDPiah1eREbGYd6vLekwbwC/lxYq vzbvq40yp9ogWv38RKKGPiHH0xzHjBvhX4cbmOqiX1gnWnrG+GoSWPqHQZMrBmzy8RIZt 2mBAVTGFpzKkDCkRfNN6Ulwu9H0sQ0R14vJo0y+cILhkCEyd6hQ+gCV/Ro1YnU+dj96oY dwyQ3lDbZMSxNSOXWIqczbHJVxi+7abIrNHv8Zy61DkrJLOBoDr8y3IJZXnJN0OqjyHU9 NehUwIXu52SRBFfKGYX+Ntzrc6pmexs4uhEIjplHzDXH9gGFcDpb1dxbjGpjXMZaPAA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Oj0+YR5p; 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 A6267606A32E for ; Sat, 7 Nov 2026 10:34:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Oj0+YR5p Received: by smtp.kernel.org (Postfix) with ESMTPSA id 239671F0089F; Sat, 7 Nov 2026 10:34:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047659; bh=K7AXBMAt7B8q9vhp6U935PfPsBA33vBmhx7DUqAXU+4=; h=From:To:Cc:Subject:Date; b=Oj0+YR5poiiu4oCPtV+RM5U524kq15ZtrrNNUSqaWvDfraqsGoxz9VxielEOFv3B7 oSR1QoZKeVBIjz9WsOeS3dNe7Os4HuZ555WfIVEzKHxY8rnj1QAtSe/yhqUlnF32qQ PnhGcWqeFb40D0a2f6h1GwpdqWwZqSxp7rBjqHpaU25ZRdywfVcJByliXfhUOUaJpn jz79NbMHZ1n93P17kJD4R6zRIvYty+ip/d/IABA02+yOJR0liKQnkSOuiY4m7VmIRk gs0A2kUF58SKdqLaWk9ZB9qr7yivnecFAHWXWNoER4yruc6T0vg+MYjPIPYSdGFQ/T k6NysI3hMP6HQ== From: Sasha Levin To: andrey.misyrov@gmail.com, deller@gmx.de Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] fbdev: core: Initialize modelist in framebuffer_alloc()" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:34:18 -0500 Message-ID: <20261107053418-failed-6.6-0c9cb9321cb3@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0c9cb9321cb3863b52bdea4b8ae5a27705762c9e # git commit -s git send-email --to '' --in-reply-to '20261107053418-failed-6.6-0c9cb9321cb3@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 0c9cb9321cb3863b52bdea4b8ae5a27705762c9e Mon Sep 17 00:00:00 2001 From: Andrey Misiurov Date: Mon, 12 Oct 2026 19:53:38 +0200 Subject: [PATCH] fbdev: core: Initialize modelist in framebuffer_alloc() framebuffer_alloc() returns zeroed memory, so info->modelist starts out with NULL next and prev pointers. The list head is initialized only later, by fb_videomode_to_modelist() or by do_register_framebuffer(). The "fix potential memory leak" commits listed below added fb_destroy_modelist(&info->modelist) to the probe error paths of s3fb, tdfxfb, tridentfb, i740fb and carminefb. These paths can run before the list head is initialized: - s3fb, tdfxfb, tridentfb and i740fb call fb_videomode_to_modelist() only after a successful EDID read, and tridentfb can also hit the error path on an ioremap() or kmalloc() failure before that; - carminefb jumps to the error path when fb_find_mode() fails, before its fb_videomode_to_modelist() call. fb_destroy_modelist() then dereferences the NULL head. Reproduced on Debian 12 (6.1.180) by binding s3fb to a VGA device without EDID and forcing fb_alloc_cmap() to fail: s3fb 0000:00:03.0: cannot allocate colormap BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:fb_destroy_modelist+0x10/0x80 Call Trace: s3_pci_probe.cold+0x12b/0x2bf [s3fb] local_pci_probe+0x41/0x80 pci_device_probe+0xc3/0x240 really_probe+0xde/0x380 __driver_probe_device+0x84/0x150 driver_probe_device+0x1f/0x90 __driver_attach+0xce/0x1c0 bus_for_each_dev+0x87/0xd0 bus_add_driver+0x1ae/0x200 driver_register+0x89/0xe0 do_one_initcall+0x59/0x220 do_init_module+0x4a/0x1f0 Initialize the list head in framebuffer_alloc(), so info->modelist is always a valid, possibly empty, list and fb_destroy_modelist() is safe on every error path. Keep the lazy initialization in do_register_framebuffer(), as drivers that embed struct fb_info rather than calling framebuffer_alloc() still depend on it. Fixes: 3b0ed04bc852 ("fbdev: s3fb: fix potential memory leak in s3_pci_probe()") Fixes: bb019d755366 ("fbdev: tdfxfb: fix potential memory leak in tdfxfb_probe()") Fixes: 7a35ec619d9a ("fbdev: tridentfb: fix potential memory leak in trident_pci_probe()") Fixes: 5936063409af ("fbdev: i740fb: fix potential memory leak in i740fb_probe()") Fixes: 6fcca16a2b19 ("fbdev: carminefb: fix potential memory leak in alloc_carmine_fb()") Cc: stable@vger.kernel.org Signed-off-by: Andrey Misiurov Signed-off-by: Helge Deller --- drivers/video/fbdev/core/fb_info.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/video/fbdev/core/fb_info.c b/drivers/video/fbdev/core/fb_info.c index 52f9bd2c5417a..05988a936bebb 100644 --- a/drivers/video/fbdev/core/fb_info.c +++ b/drivers/video/fbdev/core/fb_info.c @@ -43,6 +43,7 @@ struct fb_info *framebuffer_alloc(size_t size, struct device *dev) info->device = dev; info->fbcon_rotate_hint = -1; info->blank = FB_BLANK_UNBLANK; + INIT_LIST_HEAD(&info->modelist); #if IS_ENABLED(CONFIG_FB_BACKLIGHT) mutex_init(&info->bl_curve_mutex); -- 2.53.0