In the Linux kernel, the following vulnerability has been resolved:
fbcon: always restore the old font data in fbcon_do_set_font()
Commit a5a923038d70 (fbdev: fbcon: Properly revert changes when
vc_resize() failed) started restoring old font data upon failure (of
vc_resize()). But it performs so only for user fonts. It means that the
"system"/internal fonts are not restored at all. So in result, the very
first call to fbcon_do_set_font() performs no restore at all upon
failing vc_resize().
This can be reproduced by Syzkaller to crash the system on the next
invocation of font_get(). It's rather hard to hit the allocation failure
in vc_resize() on the first font_set(), but not impossible. Esp. if
fault injection is used to aid the execution/failure. It was
demonstrated by Sirius:
BUG: unable to handle page fault for address: fffffffffffffff8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286
Call Trace:
<TASK>
con_font_get drivers/tty/vt/vt.c:4558 [inline]
con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673
vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752
tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803
vfs_ioctl fs/ioctl.c:51 [inline]
...
So restore the font data in any case, not only for user fonts. Note the
later 'if' is now protected by 'old_userfont' and not 'old_data' as the
latter is always set now. (And it is supposed to be non-NULL. Otherwise
we would see the bug above again.)
References
Configurations
Configuration 1 (hide)
|
History
01 Apr 2025, 20:35
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-770 | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* |
|
| First Time |
Linux linux Kernel
Linux |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f - Patch | |
| References | () https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d - Patch | |
| References | () https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b - Patch | |
| References | () https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520 - Patch | |
| References | () https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8 - Patch |
21 Nov 2024, 09:03
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f - | |
| References | () https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d - | |
| References | () https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b - | |
| References | () https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520 - | |
| References | () https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8 - |
04 Apr 2024, 09:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2024-04-04 09:15
Updated : 2025-04-01 20:35
NVD link : CVE-2024-26798
Mitre link : CVE-2024-26798
CVE.ORG link : CVE-2024-26798
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-770
Allocation of Resources Without Limits or Throttling