{"id":"CVE-2026-98888","title":"arm64: kprobes: Allow reentering kprobes while single-stepping","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: kprobes: Allow reentering kprobes while single-stepping\n\nA kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This\ncan happen when tracing or perf…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bb0fe9121aa0824211aafa33c7d0151fd25ddb75","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f96a0606de6bcc8d937b80e6470fd7a174c17e26","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1f342b3e44c3035a837b53b217d816f7511c0d0a","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c8e84e292ed4cfc199824146da71bb4397b02a1f","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 68774caca799e9695db56d426c69acebd041c2ed","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a21bf9cb893126e8d9730995708d0be5eb167652","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 23f851ac0078a908bf3422d6467ebc1db5828c46","Linux < 5.10.271","Linux < 5.15.222","Linux < 6.1.189","Linux < 6.6.158","Linux < 6.12.111","Linux < 6.18.53","Linux (all versions)"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T11:37:46.984Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98888","references":[{"url":"https://git.kernel.org/stable/c/bb0fe9121aa0824211aafa33c7d0151fd25ddb75"},{"url":"https://git.kernel.org/stable/c/f96a0606de6bcc8d937b80e6470fd7a174c17e26"},{"url":"https://git.kernel.org/stable/c/1f342b3e44c3035a837b53b217d816f7511c0d0a"},{"url":"https://git.kernel.org/stable/c/c8e84e292ed4cfc199824146da71bb4397b02a1f"},{"url":"https://git.kernel.org/stable/c/68774caca799e9695db56d426c69acebd041c2ed"},{"url":"https://git.kernel.org/stable/c/a21bf9cb893126e8d9730995708d0be5eb167652"},{"url":"https://git.kernel.org/stable/c/23f851ac0078a908bf3422d6467ebc1db5828c46"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.579Z","slug":"CVE-2026-98888","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\narm64: kprobes: Allow reentering kprobes while single-stepping\n\nA kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This\ncan happen when tracing or perf code runs from the debug exception path\nwhile the first kprobe is preparing or executing its out-of-line\nsingle-step instruction.\n\nCurrently arm64 treats a kprobe hit in KPROBE_HIT_SS as unrecoverable,\nthe same as a hit in KPROBE_REENTER. This is too strict. A hit in\nKPROBE_HIT_SS is still a one-level reentry and can be handled by saving\nthe current kprobe state and setting up single-step for the new probe,\njust like reentry from KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE.\n\nThe truly unrecoverable case is hitting another kprobe while already in\nKPROBE_REENTER, because the reentry save area has already been consumed.\n\nMove KPROBE_HIT_SS to the recoverable reentry cases and leave\nKPROBE_REENTER as the unrecoverable nested reentry case.\n\nThis change also requires saving saved_irqflag in struct prev_kprobe.\nWhen a nested kprobe calls kprobes_save_local_irqflag(), it overwrites\nkcb->saved_irqflag with the currently masked DAIF value, losing the\nouter kprobe's original DAIF state. Without this fix, when the outer\nkprobe's single-step finishes, kprobes_restore_local_irqflag() applies\nthe wrong DAIF mask and leaves interrupts permanently disabled.\n\nExtend struct prev_kprobe with a saved_irqflag field and save/restore it\nalongside kp and status. This ensures the outer kprobe's original\ninterrupt state is preserved across reentry.\n\nThis mirrors the x86 fix in commit 6a5022a56ac3\n(\"kprobes/x86: Allow to handle reentered kprobe on single-stepping\").\n\n## Affected\n\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bb0fe9121aa0824211aafa33c7d0151fd25ddb75`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f96a0606de6bcc8d937b80e6470fd7a174c17e26`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1f342b3e44c3035a837b53b217d816f7511c0d0a`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c8e84e292ed4cfc199824146da71bb4397b02a1f`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 68774caca799e9695db56d426c69acebd041c2ed`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a21bf9cb893126e8d9730995708d0be5eb167652`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 23f851ac0078a908bf3422d6467ebc1db5828c46`\n- `Linux < 5.10.271`\n- `Linux < 5.15.222`\n- `Linux < 6.1.189`\n- `Linux < 6.6.158`\n- `Linux < 6.12.111`\n- `Linux < 6.18.53`\n- `Linux (all versions)`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}