FKIE_CVE-2023-53747

Vulnerability from fkie_nvd - Published: 2025-12-08 02:15 - Updated: 2026-10-15 22:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF After a call to console_unlock() in vcs_write() the vc_data struct can be freed by vc_port_destruct(). Because of that, the struct vc_data pointer must be reloaded in the while loop in vcs_write() after console_lock() to avoid a UAF when vcs_size() is called. Syzkaller reported a UAF in vcs_size(). BUG: KASAN: slab-use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215) Read of size 4 at addr ffff8880beab89a8 by task repro_vcs_size/4119 Call Trace: <TASK> __asan_report_load4_noabort (mm/kasan/report_generic.c:380) vcs_size (drivers/tty/vt/vc_screen.c:215) vcs_write (drivers/tty/vt/vc_screen.c:664) vfs_write (fs/read_write.c:582 fs/read_write.c:564) ... <TASK> Allocated by task 1213: kmalloc_trace (mm/slab_common.c:1064) vc_allocate (./include/linux/slab.h:559 ./include/linux/slab.h:680 drivers/tty/vt/vt.c:1078 drivers/tty/vt/vt.c:1058) con_install (drivers/tty/vt/vt.c:3334) tty_init_dev (drivers/tty/tty_io.c:1303 drivers/tty/tty_io.c:1415 drivers/tty/tty_io.c:1392) tty_open (drivers/tty/tty_io.c:2082 drivers/tty/tty_io.c:2128) chrdev_open (fs/char_dev.c:415) do_dentry_open (fs/open.c:921) vfs_open (fs/open.c:1052) ... Freed by task 4116: kfree (mm/slab_common.c:1016) vc_port_destruct (drivers/tty/vt/vt.c:1044) tty_port_destructor (drivers/tty/tty_port.c:296) tty_port_put (drivers/tty/tty_port.c:312) vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2)) vt_ioctl (drivers/tty/vt/vt_ioctl.c:903) tty_ioctl (drivers/tty/tty_io.c:2778) ... The buggy address belongs to the object at ffff8880beab8800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 424 bytes inside of freed 1024-byte region [ffff8880beab8800, ffff8880beab8c00) The buggy address belongs to the physical page: page:00000000afc77580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbeab8 head:00000000afc77580 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 000fffffc0010200 ffff888100042dc0 ffffea000426de00 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880beab8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880beab8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880beab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0deff678157333d775af190f84696336cdcccd6d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/11dddfbb7a4e62489b01074d6c04d9d1b42e4047
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1de42e7653d6714a7507ba6696151a1fa028c69f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3338d0b9acde770ee588eead5cac32c25e7048fc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/934de9a9b659785fed3e820bc0c813a460c71fea
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a4e3c4c65ae8510e01352c9a4347e05c035b2ce2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/vt/vc_screen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "934de9a9b659785fed3e820bc0c813a460c71fea",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "0deff678157333d775af190f84696336cdcccd6d",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "a4e3c4c65ae8510e01352c9a4347e05c035b2ce2",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "11dddfbb7a4e62489b01074d6c04d9d1b42e4047",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "3338d0b9acde770ee588eead5cac32c25e7048fc",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "1de42e7653d6714a7507ba6696151a1fa028c69f",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            },
            {
              "lessThan": "8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357",
              "status": "affected",
              "version": "ac751efa6a0d70f2c9daef5c7e3a92270f5c2dff",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/vt/vc_screen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.38"
            },
            {
              "lessThan": "2.6.38",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.14.*",
              "status": "unaffected",
              "version": "4.14.327",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.19.*",
              "status": "unaffected",
              "version": "4.19.284",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.244",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.181",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.3.*",
              "status": "unaffected",
              "version": "6.3.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF\n\nAfter a call to console_unlock() in vcs_write() the vc_data struct can be\nfreed by vc_port_destruct(). Because of that, the struct vc_data pointer\nmust be reloaded in the while loop in vcs_write() after console_lock() to\navoid a UAF when vcs_size() is called.\n\nSyzkaller reported a UAF in vcs_size().\n\nBUG: KASAN: slab-use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215)\nRead of size 4 at addr ffff8880beab89a8 by task repro_vcs_size/4119\n\nCall Trace:\n \u003cTASK\u003e\n__asan_report_load4_noabort (mm/kasan/report_generic.c:380)\nvcs_size (drivers/tty/vt/vc_screen.c:215)\nvcs_write (drivers/tty/vt/vc_screen.c:664)\nvfs_write (fs/read_write.c:582 fs/read_write.c:564)\n...\n \u003cTASK\u003e\n\nAllocated by task 1213:\nkmalloc_trace (mm/slab_common.c:1064)\nvc_allocate (./include/linux/slab.h:559 ./include/linux/slab.h:680\n    drivers/tty/vt/vt.c:1078 drivers/tty/vt/vt.c:1058)\ncon_install (drivers/tty/vt/vt.c:3334)\ntty_init_dev (drivers/tty/tty_io.c:1303 drivers/tty/tty_io.c:1415\n    drivers/tty/tty_io.c:1392)\ntty_open (drivers/tty/tty_io.c:2082 drivers/tty/tty_io.c:2128)\nchrdev_open (fs/char_dev.c:415)\ndo_dentry_open (fs/open.c:921)\nvfs_open (fs/open.c:1052)\n...\n\nFreed by task 4116:\nkfree (mm/slab_common.c:1016)\nvc_port_destruct (drivers/tty/vt/vt.c:1044)\ntty_port_destructor (drivers/tty/tty_port.c:296)\ntty_port_put (drivers/tty/tty_port.c:312)\nvt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2))\nvt_ioctl (drivers/tty/vt/vt_ioctl.c:903)\ntty_ioctl (drivers/tty/tty_io.c:2778)\n...\n\nThe buggy address belongs to the object at ffff8880beab8800\n which belongs to the cache kmalloc-1k of size 1024\nThe buggy address is located 424 bytes inside of\n freed 1024-byte region [ffff8880beab8800, ffff8880beab8c00)\n\nThe buggy address belongs to the physical page:\npage:00000000afc77580 refcount:1 mapcount:0 mapping:0000000000000000\n    index:0x0 pfn:0xbeab8\nhead:00000000afc77580 order:3 entire_mapcount:0 nr_pages_mapped:0\n    pincount:0\nflags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)\npage_type: 0xffffffff()\nraw: 000fffffc0010200 ffff888100042dc0 ffffea000426de00 dead000000000002\nraw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000\npage dumped because: kasan: bad access detected\n\nMemory state around the buggy address:\n ffff8880beab8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n ffff8880beab8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\u003effff8880beab8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n                                  ^\n ffff8880beab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n ffff8880beab8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n==================================================================\nDisabling lock debugging due to kernel taint"
    }
  ],
  "id": "CVE-2023-53747",
  "lastModified": "2026-10-15T22:17:47.940",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-53747",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-15T21:36:57.834897Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-12-08T02:15:50.057",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0deff678157333d775af190f84696336cdcccd6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/11dddfbb7a4e62489b01074d6c04d9d1b42e4047"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1de42e7653d6714a7507ba6696151a1fa028c69f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3338d0b9acde770ee588eead5cac32c25e7048fc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/934de9a9b659785fed3e820bc0c813a460c71fea"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a4e3c4c65ae8510e01352c9a4347e05c035b2ce2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}



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