CVE-2025-21948: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jxxv-c48x-753p",
  "modified" : "2025-11-03T21:33:25Z",
  "published" : "2025-04-01T18:30:52Z",
  "aliases" : [ "CVE-2025-21948" ],
  "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 <IRQ>\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 </IRQ>\n <TASK>\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 </TASK>\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't 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-476" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2025-04-01T16:15:25Z"
  }
}