// For flags

CVE-2024-26607

drm/bridge: sii902x: Fix probing race issue

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

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Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

drm/bridge: sii902x: Fix probing race issue

A null pointer dereference crash has been observed rarely on TI
platforms using sii9022 bridge:

[ 53.271356] sii902x_get_edid+0x34/0x70 [sii902x]
[ 53.276066] sii902x_bridge_get_edid+0x14/0x20 [sii902x]
[ 53.281381] drm_bridge_get_edid+0x20/0x34 [drm]
[ 53.286305] drm_bridge_connector_get_modes+0x8c/0xcc [drm_kms_helper]
[ 53.292955] drm_helper_probe_single_connector_modes+0x190/0x538 [drm_kms_helper]
[ 53.300510] drm_client_modeset_probe+0x1f0/0xbd4 [drm]
[ 53.305958] __drm_fb_helper_initial_config_and_unlock+0x50/0x510 [drm_kms_helper]
[ 53.313611] drm_fb_helper_initial_config+0x48/0x58 [drm_kms_helper]
[ 53.320039] drm_fbdev_dma_client_hotplug+0x84/0xd4 [drm_dma_helper]
[ 53.326401] drm_client_register+0x5c/0xa0 [drm]
[ 53.331216] drm_fbdev_dma_setup+0xc8/0x13c [drm_dma_helper]
[ 53.336881] tidss_probe+0x128/0x264 [tidss]
[ 53.341174] platform_probe+0x68/0xc4
[ 53.344841] really_probe+0x188/0x3c4
[ 53.348501] __driver_probe_device+0x7c/0x16c
[ 53.352854] driver_probe_device+0x3c/0x10c
[ 53.357033] __device_attach_driver+0xbc/0x158
[ 53.361472] bus_for_each_drv+0x88/0xe8
[ 53.365303] __device_attach+0xa0/0x1b4
[ 53.369135] device_initial_probe+0x14/0x20
[ 53.373314] bus_probe_device+0xb0/0xb4
[ 53.377145] deferred_probe_work_func+0xcc/0x124
[ 53.381757] process_one_work+0x1f0/0x518
[ 53.385770] worker_thread+0x1e8/0x3dc
[ 53.389519] kthread+0x11c/0x120
[ 53.392750] ret_from_fork+0x10/0x20

The issue here is as follows:

- tidss probes, but is deferred as sii902x is still missing.
- sii902x starts probing and enters sii902x_init().
- sii902x calls drm_bridge_add(). Now the sii902x bridge is ready from
DRM's perspective.
- sii902x calls sii902x_audio_codec_init() and
platform_device_register_data()
- The registration of the audio platform device causes probing of the
deferred devices.
- tidss probes, which eventually causes sii902x_bridge_get_edid() to be
called.
- sii902x_bridge_get_edid() tries to use the i2c to read the edid.
However, the sii902x driver has not set up the i2c part yet, leading
to the crash.

Fix this by moving the drm_bridge_add() to the end of the
sii902x_init(), which is also at the very end of sii902x_probe().

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/bridge: sii902x: soluciona el problema de carrera de sondeo. Rara vez se ha observado un fallo de desreferencia de puntero nulo en plataformas TI que utilizan el puente sii9022: [ 53.271356] sii902x_get_edid+0x34/0x70 [sii902x] [ 53.276066] sii902x_bridge_get_edid+0x14/0x20 [sii902x] [ 53.281381] drm_bridge_get_edid+0x20/0x34 [drm] [ 53.286305] drm_bridge_connector_get_modes+0x8c/0xcc [drm_kms_helper] [ 53 .292955] drm_helper_probe_single_connector_modes+0x190/0x538 [drm_kms_helper] [ 53.300510] drm_client_modeset_probe+0x1f0/ 0xbd4 [drm] [ 53.305958] __drm_fb_helper_initial_config_and_unlock+0x50/0x510 [drm_kms_helper] [ 53.313611] drm_fb_helper_initial_config+0x48/0x58 [drm_kms_helper] [ 53.320039] drm_f bdev_dma_client_hotplug+0x84/0xd4 [drm_dma_helper] [ 53.326401] drm_client_register+0x5c/0xa0 [drm] [ 53.331216 ] drm_fbdev_dma_setup+0xc8/0x13c [drm_dma_helper] [ 53.336881] tidss_probe+0x128/0x264 [tidss] [ 53.341174] platform_probe+0x68/0xc4 [ 53.344841] very_probe+0x188/0x3 c4 [ 53.348501] __driver_probe_device+0x7c/0x16c [ 53.352854] driver_probe_device+0x3c /0x10c [ 53.357033] __device_attach_driver+0xbc/0x158 [ 53.361472] bus_for_each_drv+0x88/0xe8 [ 53.365303] __device_attach+0xa0/0x1b4 [ 53.369135] dispositivo_initial_probe+0x14/0 x20 [ 53.373314] dispositivo_probe_bus+0xb0/0xb4 [ 53.377145] función_trabajo_probe_diferida+0xcc/0x124 [ 53.381757] Process_one_work+0x1f0/0x518 [ 53.385770] Worker_thread+0x1e8/0x3dc [ 53.389519] kthread+0x11c/0x120 [ 53.392750] ret_from_fork+0x10/0x20 El problema aquí es el siguiente: - tids s, pero se pospone ya que sii902x todavía está desaparecido. - sii902x comienza a sondear e ingresa sii902x_init(). - sii902x llama a drm_bridge_add(). Ahora el puente sii902x está listo desde la perspectiva de DRM. - sii902x llama a sii902x_audio_codec_init() y platform_device_register_data() - El registro del dispositivo de plataforma de audio provoca el sondeo de los dispositivos diferidos. - sondas tidss, que eventualmente provocan que se llame a sii902x_bridge_get_edid(). - sii902x_bridge_get_edid() intenta usar i2c para leer el edit. Sin embargo, el controlador sii902x aún no ha configurado la parte i2c, lo que provocó el fallo. Solucione este problema moviendo drm_bridge_add() al final de sii902x_init(), que también está al final de sii902x_probe().

*Credits: N/A
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* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-19 CVE Reserved
  • 2024-02-29 CVE Published
  • 2024-03-01 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.1.76
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.1.76"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.6.15
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.6.15"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.7.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.7.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.0 < 6.8
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 6.8"
en
Affected