CVE-2026-89598

Received Received - Intake

I2C Transfer in ssd1307fb from Atomic Context

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

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] [<ffff80008012f96c>] 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_vp ---truncated---

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-09-12

AI Q&A

2026-09-12

EPSS Evaluated

N/A

NVD

CVE-2026-89598

EUVD

EUVD-2026-76510

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	6.6.0-rc5-rockchip-rk356x

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves the ssd1307fb driver for SSD1307 OLED displays. The issue occurs when fbdev damage callbacks run from fbcon while printk has disabled preemption. These callbacks attempt to update the display synchronously, which leads to entering the sleeping I2C transfer path from an atomic context. This causes a scheduling while atomic bug, as I2C transfers require blocking operations that cannot occur in atomic contexts.

Detection Guidance

This vulnerability is specific to the Linux kernel's fbdev subsystem and involves I2C transfers from damage callbacks. Detection requires checking kernel logs for scheduling while atomic errors or I2C transfer issues related to ssd1307fb. Monitor logs with: dmesg | grep -i 'scheduling while atomic' or dmesg | grep -i 'ssd1307fb'.

Impact Analysis

This vulnerability can cause system instability or crashes on systems using SSD1307 OLED displays connected via I2C. It may lead to kernel warnings, system hangs, or forced reboots due to the scheduling while atomic error. Systems relying on these displays for critical functions could experience disruptions.

Mitigation Strategies

Apply the latest kernel update that includes the fix for this issue. If an update is not available, disable the ssd1307fb driver or avoid using fbcon with I2C-based displays until patched. Check kernel version with uname -r and update via your distribution's package manager.

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