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CVE-2025-21948 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: HID: appleir: Fix potential NULL dereference at raw event handle Syzkaller reports a NULL pointer dereference issue in input_event(). BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: null-ptr-deref in is_event_supported drivers/input/input.c:67 [inline] BUG: KASAN: null-ptr-deref in input_event+0x42/0xa0 drivers/input/input.c:395 Read of size 8 at addr 0000000000000028 by task syz-executor199/2949 CPU: 0 UID: 0 PID: 2949 Comm: syz-executor199 Not tainted 6.13.0-rc4-syzkaller-00076-gf097a36ef88d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 kasan_report+0xd9/0x110 mm/kasan/report.c:602 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] is_event_supported drivers/input/input.c:67 [inline] input_event+0x42/0xa0 drivers/input/input.c:395 input_report_key include/linux/input.h:439 [inline] key_down drivers/hid/hid-appleir.c:159 [inline] appleir_raw_event+0x3e5/0x5e0 drivers/hid/hid-appleir.c:232 __hid_input_report.constprop.0+0x312/0x440 drivers/hid/hid-core.c:2111 hid_ctrl+0x49f/0x550 drivers/hid/usbhid/hid-core.c:484 __usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734 dummy_timer+0x17f7/0x3960 drivers/usb/gadget/udc/dummy_hcd.c:1993 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1820 handle_softirqs+0x206/0x8d0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 __mod_timer+0x8f6/0xdc0 kernel/time/timer.c:1185 add_timer+0x62/0x90 kernel/time/timer.c:1295 schedule_timeout+0x11f/0x280 kernel/time/sleep_timeout.c:98 usbhid_wait_io+0x1c7/0x380 drivers/hid/usbhid/hid-core.c:645 usbhid_init_reports+0x19f/0x390 drivers/hid/usbhid/hid-core.c:784 hiddev_ioctl+0x1133/0x15b0 drivers/hid/usbhid/hiddev.c:794 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> This happens due to the malformed report items sent by the emulated device which results in a report, that has no fields, being added to the report list. Due to this appleir_input_configured() is never called, hidinput_connect() fails which results in the HID_CLAIMED_INPUT flag is not being set. However, it does not make appleir_probe() fail and lets the event callback to be called without the associated input device. Thus, add a check for the HID_CLAIMED_INPUT flag and leave the event hook early if the driver didn't claim any input_dev for some reason. Moreover, some other hid drivers accessing input_dev in their event callbacks do have similar checks, too. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 3.x Severity and Vector Strings:

NIST CVSS score
NIST: NVD
Base Score:  5.5 MEDIUM
Vector:  CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://git.kernel.org/stable/c/0df1ac8ee417ad76760ff076faa4518a4d861894 Patch 
https://git.kernel.org/stable/c/2ff5baa9b5275e3acafdf7f2089f74cccb2f38d1 Patch 
https://git.kernel.org/stable/c/68cdf6710f228dfd74f66ec61fbe636da2646a73 Patch 
https://git.kernel.org/stable/c/6db423b00940b05df2a1265d3c7eabafe9f1734c Patch 
https://git.kernel.org/stable/c/8d39eb8c5e14f2f0f441eed832ef8a7b654e6fee Patch 
https://git.kernel.org/stable/c/b1d95d733cd6e74f595653daddcfc357bea461e8 Patch 
https://git.kernel.org/stable/c/d335fce8b88b2353f4bb20c631698e20384e3610 Patch 
https://git.kernel.org/stable/c/fc69e2c3219d433caabba4b5d6371ba726a4b37f Patch 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-476 NULL Pointer Dereference cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

Configuration 1 ( hide )
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
3.10
Up to (excluding)
5.4.291
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
5.5
Up to (excluding)
5.10.235
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
5.11
Up to (excluding)
5.15.179
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
5.16
Up to (excluding)
6.1.131
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
6.2
Up to (excluding)
6.6.83
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
6.7
Up to (excluding)
6.12.19
 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
   Show Matching CPE(s)
From (including)
6.13
Up to (excluding)
6.13.7
 cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
   Show Matching CPE(s)
 cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
   Show Matching CPE(s)
 cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
   Show Matching CPE(s)
 cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
   Show Matching CPE(s)
 cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
   Show Matching CPE(s)

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-21948
NVD Published Date:
04/01/2025
NVD Last Modified:
04/11/2025
Source:
kernel.org