一、 漏洞 CVE-2025-38215 基础信息
漏洞信息
# fbdev：修正 do_register_framebuffer 以防止 fb_videomode_to_var 中出现 null-ptr-deref
N/A
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神龙会尽力确保数据准确，但也请结合实际情况进行甄别与判断。
神龙祝您一切顺利！
漏洞标题
fbdev: Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var
来源：美国国家漏洞数据库 NVD
漏洞描述信息
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var
If fb_add_videomode() in do_register_framebuffer() fails to allocate
memory for fb_videomode, it will later lead to a null-ptr dereference in
fb_videomode_to_var(), as the fb_info is registered while not having the
mode in modelist that is expected to be there, i.e. the one that is
described in fb_info->var.
================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901
Call Trace:
display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929
fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071
resize_screen drivers/tty/vt/vt.c:1176 [inline]
vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263
fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720
fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776
do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128
fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
================================================================
Even though fbcon_init() checks beforehand if fb_match_mode() in
var_to_display() fails, it can not prevent the panic because fbcon_init()
does not return error code. Considering this and the comment in the code
about fb_match_mode() returning NULL - "This should not happen" - it is
better to prevent registering the fb_info if its mode was not set
successfully. Also move fb_add_videomode() closer to the beginning of
do_register_framebuffer() to avoid having to do the cleanup on fail.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
来源：美国国家漏洞数据库 NVD
CVSS信息
N/A
来源：美国国家漏洞数据库 NVD
漏洞类别
N/A
来源：美国国家漏洞数据库 NVD
漏洞标题
Linux kernel 安全漏洞
来源：中国国家信息安全漏洞库 CNNVD
漏洞描述信息
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于未检查空指针导致空指针取消引用。
来源：中国国家信息安全漏洞库 CNNVD
CVSS信息
N/A
来源：中国国家信息安全漏洞库 CNNVD
漏洞类别
其他
来源：中国国家信息安全漏洞库 CNNVD
二、漏洞 CVE-2025-38215 的公开POC
| # | POC 描述 | 源链接 | 神龙链接 |
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