{"id":"CVE-2023-53747","title":"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…","summary":"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…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"Red Hat","product":"Red Hat Enterprise Linux BaseOS (v. 9)","affected":["enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_9","codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_9"],"patched":["enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_9","codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_9"],"published":"2025-12-08","updated":"2026-10-15","sourceUpdated":"2026-10-15T22:17:47.940","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-53747","references":[{"url":"https://git.kernel.org/stable/c/0deff678157333d775af190f84696336cdcccd6d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/11dddfbb7a4e62489b01074d6c04d9d1b42e4047","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1de42e7653d6714a7507ba6696151a1fa028c69f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3338d0b9acde770ee588eead5cac32c25e7048fc","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/934de9a9b659785fed3e820bc0c813a460c71fea","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a4e3c4c65ae8510e01352c9a4347e05c035b2ce2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e3d1adcad5b73c7ed0c7edb35ab68abcaa45cf67","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53747.json"},{"url":"https://access.redhat.com/security/cve/CVE-2023-53747"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2419903"},{"url":"https://www.cve.org/CVERecord?id=CVE-2023-53747"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53747"},{"url":"https://lore.kernel.org/linux-cve-announce/2025120842-CVE-2023-53747-ae4a@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2024:9315"}],"tags":["nvd","csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00139,"epssPercentile":0.03241,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:36:57.834897Z"},"scores":{"nvd":7.8,"vendor":5.5,"cna":7.8},"ingestedAt":"2026-10-15T22:48:25.418Z","slug":"CVE-2023-53747","body":"## Overview\n\nIn 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 <TASK>\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 <TASK>\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>ffff8880beab8980: 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\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2024:9315** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2024-11-12 · [advisory](https://access.redhat.com/errata/RHSA-2024:9315)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53747.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":230087,"id":"CVE-2023-53747","ts":1793124785529,"field":"cvss","old":"5.5","new":"7.8"},{"seq":230086,"id":"CVE-2023-53747","ts":1793124785529,"field":"severity","old":"medium","new":"high"},{"seq":223797,"id":"CVE-2023-53747","ts":1792238429514,"field":"cvss","old":"7.8","new":"5.5"},{"seq":223796,"id":"CVE-2023-53747","ts":1792238429514,"field":"severity","old":"high","new":"medium"}]}