GHSA-JXXV-C48X-753P

Vulnerability from github – Published: 2025-04-01 18:30 – Updated: 2025-11-03 21:33
VLAI
Details

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: __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 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

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.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2025-21948"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-04-01T16:15:25Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nHID: appleir: Fix potential NULL dereference at raw event handle\n\nSyzkaller reports a NULL pointer dereference issue in input_event().\n\nBUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline]\nBUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]\nBUG: KASAN: null-ptr-deref in is_event_supported drivers/input/input.c:67 [inline]\nBUG: KASAN: null-ptr-deref in input_event+0x42/0xa0 drivers/input/input.c:395\nRead of size 8 at addr 0000000000000028 by task syz-executor199/2949\n\nCPU: 0 UID: 0 PID: 2949 Comm: syz-executor199 Not tainted 6.13.0-rc4-syzkaller-00076-gf097a36ef88d #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nCall Trace:\n \u003cIRQ\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120\n kasan_report+0xd9/0x110 mm/kasan/report.c:602\n check_region_inline mm/kasan/generic.c:183 [inline]\n kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189\n instrument_atomic_read include/linux/instrumented.h:68 [inline]\n _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]\n is_event_supported drivers/input/input.c:67 [inline]\n input_event+0x42/0xa0 drivers/input/input.c:395\n input_report_key include/linux/input.h:439 [inline]\n key_down drivers/hid/hid-appleir.c:159 [inline]\n appleir_raw_event+0x3e5/0x5e0 drivers/hid/hid-appleir.c:232\n __hid_input_report.constprop.0+0x312/0x440 drivers/hid/hid-core.c:2111\n hid_ctrl+0x49f/0x550 drivers/hid/usbhid/hid-core.c:484\n __usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650\n usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734\n dummy_timer+0x17f7/0x3960 drivers/usb/gadget/udc/dummy_hcd.c:1993\n __run_hrtimer kernel/time/hrtimer.c:1739 [inline]\n __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803\n hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1820\n handle_softirqs+0x206/0x8d0 kernel/softirq.c:561\n __do_softirq kernel/softirq.c:595 [inline]\n invoke_softirq kernel/softirq.c:435 [inline]\n __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:662\n irq_exit_rcu+0x9/0x30 kernel/softirq.c:678\n instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]\n sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049\n \u003c/IRQ\u003e\n \u003cTASK\u003e\n asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702\n __mod_timer+0x8f6/0xdc0 kernel/time/timer.c:1185\n add_timer+0x62/0x90 kernel/time/timer.c:1295\n schedule_timeout+0x11f/0x280 kernel/time/sleep_timeout.c:98\n usbhid_wait_io+0x1c7/0x380 drivers/hid/usbhid/hid-core.c:645\n usbhid_init_reports+0x19f/0x390 drivers/hid/usbhid/hid-core.c:784\n hiddev_ioctl+0x1133/0x15b0 drivers/hid/usbhid/hiddev.c:794\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl fs/ioctl.c:892 [inline]\n __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \u003c/TASK\u003e\n\nThis happens due to the malformed report items sent by the emulated device\nwhich results in a report, that has no fields, being added to the report list.\nDue to this appleir_input_configured() is never called, hidinput_connect()\nfails which results in the HID_CLAIMED_INPUT flag is not being set. However,\nit  does not make appleir_probe() fail and lets the event callback to be\ncalled without the associated input device.\n\nThus, add a check for the HID_CLAIMED_INPUT flag and leave the event hook\nearly if the driver didn\u0027t claim any input_dev for some reason. Moreover,\nsome other hid drivers accessing input_dev in their event callbacks do have\nsimilar checks, too.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller.",
  "id": "GHSA-jxxv-c48x-753p",
  "modified": "2025-11-03T21:33:25Z",
  "published": "2025-04-01T18:30:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21948"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0df1ac8ee417ad76760ff076faa4518a4d861894"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2ff5baa9b5275e3acafdf7f2089f74cccb2f38d1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/68cdf6710f228dfd74f66ec61fbe636da2646a73"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6db423b00940b05df2a1265d3c7eabafe9f1734c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8d39eb8c5e14f2f0f441eed832ef8a7b654e6fee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1d95d733cd6e74f595653daddcfc357bea461e8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d335fce8b88b2353f4bb20c631698e20384e3610"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc69e2c3219d433caabba4b5d6371ba726a4b37f"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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