cbcvebase.
CVE-2025-38214
published 2025-07-04

CVE-2025-38214: In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix fb_set_var to prevent null-ptr-deref in fb_videomode_to_var If…

medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix fb_set_var to prevent null-ptr-deref in fb_videomode_to_var If fb_add_videomode() in fb_set_var() fails to allocate memory for fb_videomode, later it may 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 The reason is that fb_info->var is being modified in fb_set_var(), and then fb_videomode_to_var() is called. If it fails to add the mode to fb_info->modelist, fb_set_var() returns error, but does not restore the old value of fb_info->var. Restore fb_info->var on failure the same way it is done earlier in the function. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Affected

35 ranges· showing 25
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.147-1 (bookworm)linux 6.1.147-1 (bookworm)
debianlinux-6.1< linux 6.1.147-1 (bookworm)linux 6.1.147-1 (bookworm)
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ee20216f12d9482cd70e44dae5e7fabb38367c71ee20216f12d9482cd70e44dae5e7fabb38367c71
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < fab201d72fde38d081e2c5d4ad25595c535b7b22fab201d72fde38d081e2c5d4ad25595c535b7b22
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1a10d91766eb6ddfd5414e4785611e33a4fe0f9b1a10d91766eb6ddfd5414e4785611e33a4fe0f9b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ff0e037241173b574b385bff53d67567b9816db5ff0e037241173b574b385bff53d67567b9816db5
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3ca78032a388a0795201792b36e6fc9b6e6e8eed3ca78032a388a0795201792b36e6fc9b6e6e8eed
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b3071bb463ea1e6c686d0dc9638fc940f2f5cf17b3071bb463ea1e6c686d0dc9638fc940f2f5cf17
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8a3a2887794b2c8e78b3e5d6e3de724527c9f41b8a3a2887794b2c8e78b3e5d6e3de724527c9f41b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 05f6e183879d9785a3cdf2f08a498bc31b7a20aa05f6e183879d9785a3cdf2f08a498bc31b7a20aa
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.244-15.10.244-1
linuxlinux_kernel>= 0 < 6.1.147-16.1.147-1
linuxlinux_kernel>= 0 < 6.12.35-16.12.35-1
linuxlinux_kernel>= 0 < 6.12.35-16.12.35-1
linuxlinux_kernel>= 0 < 6.8.0-100.1006.8.0-100.100
linuxlinux_kernel>= 2.6.13 < 5.4.2955.4.295
linuxlinux_kernel>= 5.11 < 5.15.1865.15.186
linuxlinux_kernel>= 5.16 < 6.1.1426.1.142
linuxlinux_kernel>= 5.5 < 5.10.2395.10.239
linuxlinux_kernel>= 6.13 < 6.15.46.15.4
linuxlinux_kernel>= 6.2 < 6.6.956.6.95
linuxlinux_kernel>= 6.7 < 6.12.356.12.35

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.6MEDIUM