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 7B7E1448BB3; Sat, 26 Sep 2026 13:17:13 +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=1790428634; cv=none; b=C4dom8yA3cPqYnrgQHXyjVYQWH/vdPyEaYUS2jCvouEYsA5EmK4T3797WOD9wCrld/3IgRUfDhCUvO6Ve5MkxPo3c5ZsNWvDyS94lNODjxucHB9F+2L6BjaM5KsQZe0UNg8rsA78KlOUBfWPZnop2EL/SkTT9QXxIzPimpurLn4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790428634; c=relaxed/simple; bh=nk6tWgfWfCzVJ80HB+E43ly8yTYHGUV6LKNb27D3Q4g=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=D7o4mtm5shdS26vypbZwSsWcHUpzsMKGnrXi2951SxhVq6pjdogVePRyyHVNcSjFyozAwFl6QYUTiuosjkYrmMCmo3GfA9nCWclta7lyvbCnswRBy68c8UMMdzueebzpIRlO89MbHXQBRdNmsjee4eqYwwO1l36f3KOhqCAsj+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=m+w3z9c4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="m+w3z9c4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FC151F000FF; Sat, 26 Sep 2026 13:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790428633; bh=6K6aRJbm7O7grujLpKfmwFADDk/4ClgBVhZ4DN1sLn4=; h=From:Subject:Date:To:Cc; b=m+w3z9c4uR3Tk1a+jEp1F89n3VGMnDg0YXzs4afked4AIoPSeW26r/FEPyUP5w3MT LZ2iWYiB/6baEW0O3nPZdNcpkLC11oTcAWoUadbraQWCQZJnerna1kKGZJoMQxyjYG rs6iDi/wsSr2kd8OHMPjgQ0Y0gkqN1KMZKRSsCvnAh/SkThlHWgE6bHMfOtg5QtBLF Pb733RnWIiObeUfPHruNaHFUnfKxguYogzsbsIJB4smncQwe9BKB7akbl5v5OeG3nE P4AZIbTJiwRjzrJ8rLKxT6ZvfXhoJTAc54l3H668uOwNTM1Nn/a9BgNGIfEQ/WQ7eC GHFp5ppRc3CYg== From: "Lorenzo Stoakes (ARM)" Subject: [PATCH 0/6] fbdev: fixup callers which ignore errors from fb_deferred_io_init() Date: Sat, 26 Sep 2026 14:16:58 +0100 Message-Id: <20260926-fix-fbdefio-error-handling-v1-0-a94810b6e263@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQqAIBBA0avErBtQo6CuEi0yxxoIjREiCO/e0 PLD479QSJgKTM0LQjcXzknDtg1sx5p2Qg7a4IwbzOgGjPxg9IEiZySRLKgsnJx2XL3tem/s2G0 edHCJquefz0utH+HA3R5sAAAA X-Change-ID: 20260926-fix-fbdefio-error-handling-ab135b0193cb To: Helge Deller , Javier Martinez Canillas , Thomas Zimmermann , =?utf-8?q?Bruno_Pr=C3=A9mont?= , Jiri Kosina , Benjamin Tissoires , Bernie Thompson , Greg Kroah-Hartman , Steve Glendinning , Florian Tobias Schandinat Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Steve Glendinning , "Lorenzo Stoakes (ARM)" , stable@vger.kernel.org X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1832; i=ljs@kernel.org; h=from:subject:message-id; bh=nk6tWgfWfCzVJ80HB+E43ly8yTYHGUV6LKNb27D3Q4g=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLK2H71yU8auJ7GmyeWWIqPwfdbAMG+nBPuSZTY5e++wm 78PFDbqKGVhEONikBVTZHn+RXx/kEjYvM4L/m4wc1iZQIYwcHEKwETOljAybFJ1X2V3r/74+UyO Z8pClw9dTdZ8MXkq+6Y5Gn9vrucKWs/wP+IY53zuhRM/zVQJZviWOPFZ8S+j8/OF5ly1WKaYZpl uxgUA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 Commit 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct") converted fb_deferred_io_init() from a void function to one returning an error value. However a number of callers don't seem to have been apprised of the fact and continue to treat it like a void function. This is problematic, as upon allocation failure, struct fb_info->fbdefio_state is NULL. That means when a subsequent operation is performed upon the driver, for instance opening the file, a NULL pointer dereference occurs. Update all of the remaining drivers which fail to check this to do so. This issue was discovered as part of a separate series which updated logic belonging to ssd1307fb. Also fix up a separate issue with a BUG_ON() occurring on allocation failure for udlfb and smcufx. Signed-off-by: Lorenzo Stoakes (ARM) --- Lorenzo Stoakes (ARM) (6): fbdev: ssd1307fb: check for fb_deferred_io_init() error fbdev: xen-fbfront: check for fb_deferred_io_init() error HID: picoLCD: check for fb_deferred_io_init() error fbdev: udlfb: check for fb_deferred_io_init() error fbdev: smscufx: check for fb_deferred_io_init() error fbdev: sh_mobile_lcdc: check for fb_deferred_io_init() error drivers/hid/hid-picolcd_fb.c | 12 +++++++++--- drivers/video/fbdev/sh_mobile_lcdcfb.c | 6 +++++- drivers/video/fbdev/smscufx.c | 9 ++++++--- drivers/video/fbdev/ssd1307fb.c | 6 +++++- drivers/video/fbdev/udlfb.c | 9 ++++++--- drivers/video/fbdev/xen-fbfront.c | 7 ++++++- 6 files changed, 37 insertions(+), 12 deletions(-) --- base-commit: 6812ce4e4379ffc99c52401ec28f0d7ffbc36206 change-id: 20260926-fix-fbdefio-error-handling-ab135b0193cb Best regards, -- Lorenzo Stoakes (ARM)