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 892B6582B97 for ; Fri, 11 Sep 2026 19:57:58 +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=1789156692; cv=none; b=IP0idW/NRq2K3AH+uf1/RyJ263XPxrKH1M81gWMPPSbEjwzf+RykVnTwJDxt5rHOuhOqNx5bGBU/c/9eqzOEiVuqTLbFhCSDXy68Q8qM1AHdJNMMsITqvbXIl+6DDZ9/ZXXXItwy+1b6zdrWzXuR2S78zKCOULwXyjsSq/N6qXA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156692; c=relaxed/simple; bh=ubCzbBDvbqeGRuKn7wrhuQlTkK8VOwbu9mIhkr7lUe0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=A9LwY8h9Trnu6Rc9/Z5v3dkpAVZ5wcWe+w58+ztShNNRLI/aXcWeRw8P52JdNEy11oFQaBEOJNuwH0rYvF60LScpvtXLLOnKYrKPQoeiWV4vEYlB0eqXfIJTO+sB9mB+oha71+p2FDIrBZ593XubqGba5aFw4bXMEZX6gKScr5Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nqw6+8qG; 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="nqw6+8qG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CD2F1F0089E; Fri, 11 Sep 2026 19:57:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156678; bh=3f9eKHuY64JZHYeqquA9V8mY0i/JufiN5ofmR/weCEw=; h=From:To:Cc:Subject:Date:Reply-To; b=nqw6+8qG+DAM6185ZbkObb0QDA4Lh8+odbWy5dPJd1G9VkDoh0j/YwwcmTivDBYwX x/DvpiFdUmZwgcPxnP56SBtCoxCDmtAS2+//aRwcleJtTeUONqsTF0YXvk27Mx9Jtl g2QbptVjgnEH8121l2jjK5M1b+EOUaR+8AJnTXXU= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89598: fbdev: ssd1307fb: defer I2C transfers from damage callbacks Date: Fri, 11 Sep 2026 21:44:47 +0200 Message-ID: <2026091132-CVE-2026-89598-5af1@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=7565; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=thLQ982FkUtUTWQnUcbw9i1Z/oDVKPr84QTAPBphMJc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLInNuOLdVssmlMPmWdj4r7HGSVmIRMl+6fo31ksKlF 4ziDgR0xLIwCDIxyIopsnzZxnN0f8UhRS9D29Mwc1iZQIYwcHEKwETu/GSY7/8/YyN/XfeUp+aN R9pzFv5l7OPcxDA/QDTtU7J+513FVPGmm22FdXMWKzwCAA== 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: fbdev: ssd1307fb: defer I2C transfers from damage callbacks The fbdev damage callbacks may run from fbcon while printk has disabled preemption. They currently update the display synchronously, which enters the sleeping I2C transfer path from atomic context. A complete report from an RK3566 system follows: [ 258.129004] watchdog: watchdog0: watchdog did not stop! [ 258.129067] BUG: scheduling while atomic: systemd/1/0x00000003 [ 258.129076] Modules linked in: algif_hash algif_skcipher af_alg bnep binfmt_misc lz4hc lz4 zram snd_soc_hdmi_codec brcmfmac_wcc hci_uart fb_ssd1306(C) fbtft(C) btqca btrtl btintel btsdio snd_soc_simple_card motorcomm pwm_fan snd_soc_simple_card_utils ssd130x_spi nls_iso8859_1 ssd130x btbcm drm_shmem_helper display_connector brcmfmac ssd1307fb brcmutil bluetooth cfg80211 rfkill snd_soc_rockchip_i2s_tdm snd_soc_rk817 hantro_vpu snd_soc_core snd_compress snd_pcm_dmaengine v4l2_vp9 snd_pcm v4l2_h264 rockchip_rga snd_timer rk_crypto2 spi_rockchip_sfc videobuf2_dma_contig snd sm3_generic v4l2_mem2mem videobuf2_dma_sg dwmac_rk sm3 soundcore videobuf2_memops videobuf2_v4l2 stmmac_platform dw_hdmi_cec videodev videobuf2_common dw_hdmi_i2s_audio stmmac rk817_charger pcs_xpcs mc cpufreq_dt sch_fq_codel ip_tables x_tables autofs4 [ 258.129215] Preemption disabled at: [ 258.129216] [] vprintk_emit+0x11c/0x340 [ 258.129234] CPU: 0 PID: 1 Comm: systemd Tainted: G C 6.6.0-rc5-rockchip-rk356x #4 [ 258.129239] Hardware name: Rockchip RK3566 OPi 3B (DT) [ 258.129243] Call trace: [ 258.129245] dump_backtrace+0xa0/0x128 [ 258.129252] show_stack+0x20/0x38 [ 258.129256] dump_stack_lvl+0x60/0xb0 [ 258.129265] dump_stack+0x18/0x28 [ 258.129269] __schedule_bug+0xa0/0xc8 [ 258.129274] __schedule+0x9ac/0xd30 [ 258.129279] schedule+0x60/0x100 [ 258.129282] schedule_timeout+0x194/0x338 [ 258.129289] rk3x_i2c_xfer_common.isra.0+0x384/0x498 [ 258.129296] rk3x_i2c_xfer+0x20/0x60 [ 258.129300] __i2c_transfer+0x194/0x648 [ 258.129308] i2c_transfer+0x9c/0x130 [ 258.129313] i2c_transfer_buffer_flags+0x64/0x98 [ 258.129318] ssd1307fb_update_rect+0x42c/0x560 [ssd1307fb] [ 258.129334] ssd1307fb_defio_imageblit+0x34/0x50 [ssd1307fb] [ 258.129343] soft_cursor+0x13c/0x210 [ 258.129350] bit_cursor+0x2dc/0x550 [ 258.129354] fbcon_cursor+0xec/0x108 [ 258.129359] hide_cursor+0x44/0xc8 [ 258.129365] vt_console_print+0x398/0x3b0 [ 258.129370] console_flush_all.isra.0+0x17c/0x410 [ 258.129377] console_unlock+0x4c/0x100 [ 258.129382] vprintk_emit+0x1c8/0x340 [ 258.129386] vprintk_default+0x40/0x58 [ 258.129389] vprintk+0xb8/0xd0 [ 258.129392] _printk+0x68/0x98 [ 258.129398] watchdog_release+0x170/0x230 [ 258.129404] __fput+0xbc/0x288 [ 258.129409] __fput_sync+0x58/0x70 [ 258.129413] __arm64_sys_close+0x40/0x90 [ 258.129419] invoke_syscall+0x4c/0x118 [ 258.129426] el0_svc_common.constprop.0+0x48/0xf0 [ 258.129432] do_el0_svc+0x24/0x38 [ 258.129437] el0_svc+0x48/0x100 [ 258.129443] el0t_64_sync_handler+0xc0/0xc8 [ 258.129448] el0t_64_sync+0x190/0x198 [ 258.573087] ------------[ cut here ]------------ [ 258.573098] DEBUG_LOCKS_WARN_ON(val > preempt_count()) [ 258.573111] WARNING: CPU: 0 PID: 1 at kernel/sched/core.c:5871 preempt_count_sub+0x9c/0x148 [ 258.573130] Modules linked in: algif_hash algif_skcipher af_alg bnep binfmt_misc lz4hc lz4 zram snd_soc_hdmi_codec brcmfmac_wcc hci_uart fb_ssd1306(C) fbtft(C) btqca btrtl btintel btsdio snd_soc_simple_card motorcomm pwm_fan snd_soc_simple_card_utils ssd130x_spi nls_iso8859_1 ssd130x btbcm drm_shmem_helper display_connector brcmfmac ssd1307fb brcmutil bluetooth cfg80211 rfkill snd_soc_rockchip_i2s_tdm snd_soc_rk817 hantro_vpu snd_soc_core snd_compress snd_pcm_dmaengine v4l2_vp9 snd_pcm v4l2_h264 rockchip_rga snd_timer rk_crypto2 spi_rockchip_sfc videobuf2_dma_contig snd sm3_generic v4l2_mem2mem videobuf2_dma_sg dwmac_rk sm3 soundcore videobuf2_memops videobuf2_v4l2 stmmac_platform dw_hdmi_cec videodev videobuf2_common dw_hdmi_i2s_audio stmmac rk817_charger pcs_xpcs mc cpufreq_dt sch_fq_codel ip_tables x_tables autofs4 [ 258.573268] CPU: 0 PID: 1 Comm: systemd Tainted: G WC 6.6.0-rc5-rockchip-rk356x #4 [ 258.573274] Hardware name: Rockchip RK3566 OPi 3B (DT) ** 37 printk messages dropped ** [ 258.574064] Preemption disabled at: ** 42 printk messages dropped ** [ 259.190237] Preemption disabled at: Track damage in the driver's private data under a spinlock and merge multiple updates into a bounding rectangle. Queue the existing deferred-I/O work immediately for damage reported by fbdev drawing and write helpers, so allocation and I2C transfers run from process context without adding the configured mmap refresh delay. Keep full-screen updates for dirty mmap pages, for which no precise rectangle is available. Tested on an RK3566 board with a 128x64 OLED by running five rounds of 250 KERN_EMERG messages in total while issuing framebuffer writes every 15 ms. No atomic-sleep, preemption, or lockdep warning occurred. Kprobe tracing also confirmed that cursor-only damage remained an 8x16 partial update. The Linux kernel CVE team has assigned CVE-2026-89598 to this issue. Affected and fixed versions =========================== Issue introduced in 3.8 with commit a2ed00da5047806233e288b991d9be997a5eb214 and fixed in 6.12.109 with commit b64f3497a0cd7bbd26d6c268eebd217d8062fcee Issue introduced in 3.8 with commit a2ed00da5047806233e288b991d9be997a5eb214 and fixed in 6.18.50 with commit 3bcab9b21f71d52bd1b2e03b80f29516bb000593 Issue introduced in 3.8 with commit a2ed00da5047806233e288b991d9be997a5eb214 and fixed in 7.2.4 with commit 1981e54ac137f773fb25a7209a42b75213868306 Issue introduced in 3.8 with commit a2ed00da5047806233e288b991d9be997a5eb214 and fixed in 7.3-rc1 with commit 9ad709afdfa32509ed64938a6d9cd00db3cd54c2 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-2026-89598 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/video/fbdev/ssd1307fb.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/b64f3497a0cd7bbd26d6c268eebd217d8062fcee https://git.kernel.org/stable/c/3bcab9b21f71d52bd1b2e03b80f29516bb000593 https://git.kernel.org/stable/c/1981e54ac137f773fb25a7209a42b75213868306 https://git.kernel.org/stable/c/9ad709afdfa32509ed64938a6d9cd00db3cd54c2