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=1794046916; b=C34HAMTAWA7bRWskCrnIN+j/v6vDlD9RSLRXONNoGv6tZMF9IKQIw5EXEUTZ1TtHOhUc KFnBsNK80CYc081vhr3h8mC5NcQ6rAgMbLcq/SqZ0ixKQikHvTjkKs6e5EqKG4Yg0vR28 zkA5BhBp68Q6aY50o0k90FHkXdNxt1uhVqEibl6nAo/DEEHnS0qETleupFt8zz++s4GCD 0vD7m0s9oY9SizGJpnW4iOxIRYN5JspdQlKrultn4J8dgiuWd/kPrKdx0Imqoz/R7TFiw UWg8W4BP7yvrHkBgk1hDiMDiGny8a9AJGX19lHAIPrPVDU6EvMvfJ+UJkTAhO1NG4XA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046916; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=QFqDUyLvsoyIXvlhDFNkb3cdpDWZ9LfVnzSLt9HYSO0=; b=sgMtrMg3D66VbomVaI2balvvr5s7ASd47sPJlEBQOOI7M1BN99hRIIHk2z44MRSwTssU lRzSVqkBdc6NmZz9iTG1qdT7HCCAC8/NGFz2GNxAQp++CZ5secSn72M0fhrxqP75xHEfp /Qz1gUj1nnm54FKVbxhjA+ECdIzqk5vWoR+PiLlV4Kq6EEvQsLKyuRvXL/rikwlZrAqW9 nUr5kWGSzSl4SoicmEemqf54GIVY+xvr94HyV4NPe8207Z2a/zr3h0flRFZA5WjlVHiy/ l9pjvaLGajxs88AsAytNIGJjZLSETLv2PJga3ju+BQGHEsJ79ROr6wy1MdViPxH6msg== 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=JRD+J0XN; 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 29A0F606D81B for ; Sat, 7 Nov 2026 10:21:55 +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=JRD+J0XN Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61B3C1F008A1; Sat, 7 Nov 2026 10:21:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046915; bh=QFqDUyLvsoyIXvlhDFNkb3cdpDWZ9LfVnzSLt9HYSO0=; h=From:To:Cc:Subject:Date; b=JRD+J0XNp7vcW16V0A0mAfVWHtWOnx1RqScbGdCEKzxycAk4ad8dYvI4ppJWdvqEI Z4Jnr7/OnzOSbJAK+10uqi/RNCq59CatX97JK0b98jt2TNckKm2EKUBNl7C88gZSPR 0apliQyI8Wa1bOQmAiWRX3evgWeMcUd+IBZeZv1s1NEZYZu+A15SjAb/9ljzQwA9fV WaY2fRpwaLmBPyleiq064eW6gX1LcomSCL9A3pN/UrB+dBweyoR9LNwDeO8t44AU1t XLFbUoRDiuTVNyfTe8hLxN3v3ELwTthQuL6tPY56AEC2UEPqPMrikPYwAv6ZysnMu6 mYrfFEq9Yglsg== 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 6.12-stable tree Date: Sat, 7 Nov 2026 05:21:54 -0500 Message-ID: <20261107052154-failed-6.12-0c9cb9321cb3@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 6.12-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-6.12.y git checkout FETCH_HEAD git cherry-pick -x 0c9cb9321cb3863b52bdea4b8ae5a27705762c9e # git commit -s git send-email --to '' --in-reply-to '20261107052154-failed-6.12-0c9cb9321cb3@kernel.org' --subject-prefix 'PATCH 6.12.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