{
  "cveId": "CVE-2023-52499",
  "url": "https://patchblox.com/security/cve/CVE-2023-52499",
  "summary": "CVE-2023-52499 is fixed in linux on 1 platform, first by DEBIAN-CVE-2023-52499, released March 2, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  powerpc/47x: Fix 47x syscall return crash  Eddie...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  powerpc/47x: Fix 47x syscall return crash  Eddie reported that newer kernels were crashing during boot on his 476 FSP2 system:    kernel tried to execute user page (b7ee2000) - exploit attempt? (uid: 0)   BUG: Unable to handle kernel instruction fetch   Faulting instruction address: 0xb7ee2000   Oops: Kernel access of bad area, sig: 11 [#1]   BE PAGE_SIZE=4K FSP-2   Modules linked in:   CPU: 0 PID: 61 Comm: mount Not tainted 6.1.55-d23900f.ppcnf-fsp2 #1   Hardware name: ibm,fsp2 476fpe 0x7ff520c0 FSP-2   NIP:\u00A0 b7ee2000 LR: 8c008000 CTR: 00000000   REGS: bffebd83 TRAP: 0400\u00A0\u00A0 Not tainted (6.1.55-d23900f.ppcnf-fs p2)   MSR:\u00A0 00000030 \u003CIR,DR\u003E\u00A0 CR: 00001000\u00A0 XER: 20000000   GPR00: c00110ac bffebe63 bffebe7e bffebe88 8c008000 00001000 00000d12 b7ee2000   GPR08: 00000033 00000000 00000000 c139df10 48224824 1016c314 10160000 00000000   GPR16: 10160000 10160000 00000008 00000000 10160000 00000000 10160000 1017f5b0   GPR24: 1017fa50 1017f4f0 1017fa50 1017f740 1017f630 00000000 00000000 1017f4f0   NIP [b7ee2000] 0xb7ee2000   LR [8c008000] 0x8c008000   Call Trace:   Instruction dump:   XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX   XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX   ---[ end trace 0000000000000000 ]---  The problem is in ret_from_syscall where the check for icache_44x_need_flush is done. When the flush is needed the code jumps out-of-line to do the flush, and then intends to jump back to continue the syscall return.  However the branch back to label 1b doesn\u0027t return to the correct location, instead branching back just prior to the return to userspace, causing bogus register values to be used by the rfi.  The breakage was introduced by commit 6f76a01173cc (\u0022powerpc/syscall: implement system call entry/exit logic in C for PPC32\u0022) which inadvertently removed the \u00221\u0022 label and reused it elsewhere.  Fix it by adding named local labels in the correct locations. Note that the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n compiles.",
  "published": "2024-03-02T22:15:47Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00222,
  "epssPercentile": 0.12854,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.64-1",
      "fix": "DEBIAN-CVE-2023-52499",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2023-52499",
      "released": "2024-03-02T22:15:47Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.5.8-1",
      "fix": "DEBIAN-CVE-2023-52499",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2023-52499",
      "released": "2024-03-02T22:15:47Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.5.8-1",
      "fix": "DEBIAN-CVE-2023-52499",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2023-52499",
      "released": "2024-03-02T22:15:47Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}