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FKIE_CVE-2026-72028

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: riscv: probes: save original sp in rethook trampoline Reading a word from the stack in a kretprobe crashes a risc-v kernel. $ cd /sys/kernel/tracing/ $ echo 'r n_tty_write $stack0' > dynamic_events $ echo 1 > events/kprobes/enable Unable to handle kernel paging request at virtual address 0000000200000128 ... [<ffffffff80016d16>] regs_get_kernel_stack_nth+0x26/0x38 [<ffffffff80177196>] process_fetch_insn+0x3ee/0x760 [<ffffffff80177836>] kretprobe_trace_func+0x116/0x1f0 [<ffffffff8017795a>] kretprobe_dispatcher+0x4a/0x58 [<ffffffff8013572e>] kretprobe_rethook_handler+0x5e/0x90 [<ffffffff80180838>] rethook_trampoline_handler+0x70/0x108 [<ffffffff8001ba32>] arch_rethook_trampoline_callback+0x12/0x1c [<ffffffff8001ba84>] arch_rethook_trampoline+0x48/0x94 [<ffffffff8067872a>] tty_write+0x1a/0x30 In regs_get_kernel_stack_nth, regs->sp contains an arbitrary value. arch_rethook_trampoline saves the registers from the probed function in a struct pt_regs. sp is not saved. Instead, sp is decremented for arch_rethook_trampoline's local stack. Fix this crash and save the original sp along with the other registers. Use a0 as a temporary register, it is overwritten anyway. [pjw@kernel.org: added Fixes tag; cc'ed stable]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2faf0198168d2017cb528a79f76c560fda3b6e94
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5da5cf48a432e30ded8d58087854e5383a36eff1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/91b4d76dd07f1a1f20f73dfebb42ba04ac911a56
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bc7b086a45521a986a49045907f017e3e46c763e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c386e1c591d72eab58ee2e69105c8cbc70928857
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/kernel/probes/rethook_trampoline.S"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5da5cf48a432e30ded8d58087854e5383a36eff1",
              "status": "affected",
              "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5",
              "versionType": "git"
            },
            {
              "lessThan": "c386e1c591d72eab58ee2e69105c8cbc70928857",
              "status": "affected",
              "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5",
              "versionType": "git"
            },
            {
              "lessThan": "2faf0198168d2017cb528a79f76c560fda3b6e94",
              "status": "affected",
              "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5",
              "versionType": "git"
            },
            {
              "lessThan": "91b4d76dd07f1a1f20f73dfebb42ba04ac911a56",
              "status": "affected",
              "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5",
              "versionType": "git"
            },
            {
              "lessThan": "bc7b086a45521a986a49045907f017e3e46c763e",
              "status": "affected",
              "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/kernel/probes/rethook_trampoline.S"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.12"
            },
            {
              "lessThan": "5.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nriscv: probes: save original sp in rethook trampoline\n\nReading a word from the stack in a kretprobe crashes a risc-v kernel.\n\n$ cd /sys/kernel/tracing/\n$ echo \u0027r n_tty_write $stack0\u0027 \u003e dynamic_events\n$ echo 1 \u003e events/kprobes/enable\nUnable to handle kernel paging request at virtual address 0000000200000128\n...\n[\u003cffffffff80016d16\u003e] regs_get_kernel_stack_nth+0x26/0x38\n[\u003cffffffff80177196\u003e] process_fetch_insn+0x3ee/0x760\n[\u003cffffffff80177836\u003e] kretprobe_trace_func+0x116/0x1f0\n[\u003cffffffff8017795a\u003e] kretprobe_dispatcher+0x4a/0x58\n[\u003cffffffff8013572e\u003e] kretprobe_rethook_handler+0x5e/0x90\n[\u003cffffffff80180838\u003e] rethook_trampoline_handler+0x70/0x108\n[\u003cffffffff8001ba32\u003e] arch_rethook_trampoline_callback+0x12/0x1c\n[\u003cffffffff8001ba84\u003e] arch_rethook_trampoline+0x48/0x94\n[\u003cffffffff8067872a\u003e] tty_write+0x1a/0x30\n\nIn regs_get_kernel_stack_nth, regs-\u003esp contains an arbitrary value.\n\narch_rethook_trampoline saves the registers from the probed function in a\nstruct pt_regs. sp is not saved. Instead, sp is decremented for\narch_rethook_trampoline\u0027s local stack.\n\nFix this crash and save the original sp along with the other registers.\nUse a0 as a temporary register, it is overwritten anyway.\n\n[pjw@kernel.org: added Fixes tag; cc\u0027ed stable]"
    }
  ],
  "id": "CVE-2026-72028",
  "lastModified": "2026-08-17T06:18:00.533",
  "metrics": {},
  "published": "2026-08-15T06:21:01.953",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2faf0198168d2017cb528a79f76c560fda3b6e94"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5da5cf48a432e30ded8d58087854e5383a36eff1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/91b4d76dd07f1a1f20f73dfebb42ba04ac911a56"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bc7b086a45521a986a49045907f017e3e46c763e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c386e1c591d72eab58ee2e69105c8cbc70928857"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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