CVE-2025-38558
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-08-19

Last updated on: 2025-11-28

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: Initialize frame-based format color matching descriptor Fix NULL pointer crash in uvcg_framebased_make due to uninitialized color matching descriptor for frame-based format which was added in commit f5e7bdd34aca ("usb: gadget: uvc: Allow creating new color matching descriptors") that added handling for uncompressed and mjpeg format. Crash is seen when userspace configuration (via configfs) does not explicitly define the color matching descriptor. If color_matching is not found, config_group_find_item() returns NULL. The code then jumps to out_put_cm, where it calls config_item_put(color_matching);. If color_matching is NULL, this will dereference a null pointer, leading to a crash. [ 2.746440] Unable to handle kernel NULL pointer dereference at virtual address 000000000000008c [ 2.756273] Mem abort info: [ 2.760080] ESR = 0x0000000096000005 [ 2.764872] EC = 0x25: DABT (current EL), IL = 32 bits [ 2.771068] SET = 0, FnV = 0 [ 2.771069] EA = 0, S1PTW = 0 [ 2.771070] FSC = 0x05: level 1 translation fault [ 2.771071] Data abort info: [ 2.771072] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 2.771073] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 2.771074] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 2.771075] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000a3e59000 [ 2.771077] [000000000000008c] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 2.771081] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 2.771084] Dumping ftrace buffer: [ 2.771085] (ftrace buffer empty) [ 2.771138] CPU: 7 PID: 486 Comm: ln Tainted: G W E 6.6.58-android15 [ 2.771139] Hardware name: Qualcomm Technologies, Inc. SunP QRD HDK (DT) [ 2.771140] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 2.771141] pc : __uvcg_fill_strm+0x198/0x2cc [ 2.771145] lr : __uvcg_iter_strm_cls+0xc8/0x17c [ 2.771146] sp : ffffffc08140bbb0 [ 2.771146] x29: ffffffc08140bbb0 x28: ffffff803bc81380 x27: ffffff8023bbd250 [ 2.771147] x26: ffffff8023bbd250 x25: ffffff803c361348 x24: ffffff803d8e6768 [ 2.771148] x23: 0000000000000004 x22: 0000000000000003 x21: ffffffc08140bc48 [ 2.771149] x20: 0000000000000000 x19: ffffffc08140bc48 x18: ffffffe9f8cf4a00 [ 2.771150] x17: 000000001bf64ec3 x16: 000000001bf64ec3 x15: ffffff8023bbd250 [ 2.771151] x14: 000000000000000f x13: 004c4b40000f4240 x12: 000a2c2a00051615 [ 2.771152] x11: 000000000000004f x10: ffffffe9f76b40ec x9 : ffffffe9f7e389d0 [ 2.771153] x8 : ffffff803d0d31ce x7 : 000f4240000a2c2a x6 : 0005161500028b0a [ 2.771154] x5 : ffffff803d0d31ce x4 : 0000000000000003 x3 : 0000000000000000 [ 2.771155] x2 : ffffffc08140bc50 x1 : ffffffc08140bc48 x0 : 0000000000000000 [ 2.771156] Call trace: [ 2.771157] __uvcg_fill_strm+0x198/0x2cc [ 2.771157] __uvcg_iter_strm_cls+0xc8/0x17c [ 2.771158] uvcg_streaming_class_allow_link+0x240/0x290 [ 2.771159] configfs_symlink+0x1f8/0x630 [ 2.771161] vfs_symlink+0x114/0x1a0 [ 2.771163] do_symlinkat+0x94/0x28c [ 2.771164] __arm64_sys_symlinkat+0x54/0x70 [ 2.771164] invoke_syscall+0x58/0x114 [ 2.771166] el0_svc_common+0x80/0xe0 [ 2.771168] do_el0_svc+0x1c/0x28 [ 2.771169] el0_svc+0x3c/0x70 [ 2.771172] el0t_64_sync_handler+0x68/0xbc [ 2.771173] el0t_64_sync+0x1a8/0x1ac Initialize color matching descriptor for frame-based format to prevent NULL pointer crash by mirroring the handling done for uncompressed and mjpeg formats.
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Meta Information
Published
2025-08-19
Last Modified
2025-11-28
Generated
2026-05-07
AI Q&A
2025-08-19
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38558
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 6.13 (inc) to 6.15.10 (exc)
linux linux_kernel From 6.16 (inc) to 6.16.1 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a NULL pointer dereference in the Linux kernel's USB gadget UVC driver. It occurs because the color matching descriptor for frame-based formats was not initialized properly. When userspace configuration does not explicitly define this descriptor, the kernel code attempts to dereference a NULL pointer, causing a crash. This happens in the function uvcg_framebased_make due to uninitialized color matching descriptor handling.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to crash (kernel NULL pointer dereference), leading to system instability or denial of service. Specifically, if the affected USB gadget UVC driver is used and the userspace configuration omits the color matching descriptor, the system may experience a kernel crash.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring the system logs for kernel NULL pointer dereference crashes related to the USB gadget UVC driver. Specifically, look for kernel messages indicating a crash in uvcg_framebased_make or __uvcg_fill_strm functions, or messages similar to 'Unable to handle kernel NULL pointer dereference at virtual address 000000000000008c'. Checking dmesg or journalctl logs for such errors can help detect the issue. Example commands include: 'dmesg | grep -i uvcg' or 'journalctl -k | grep -i uvcg'.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation involves updating the Linux kernel to a version that includes the fix for this vulnerability, which initializes the color matching descriptor for frame-based formats to prevent the NULL pointer crash. Until an update is applied, avoid using userspace configurations via configfs that do not explicitly define the color matching descriptor for frame-based formats, as this triggers the crash.


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