CVE-2026-64235

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64235", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.771Z", "datePublished": "2026-07-24T15:27:40.814Z", "dateUpdated": "2026-10-19T20:28:16.189Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:40:13.850Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines\n\nWith CONFIG_CALL_DEPTH_TRACKING enabled on an x86 retbleed-affected platform\n(eg: Skylake), with retbleed=stuff, registering a dynamic ftrace trampoline\ncrashes on the first call into the traced function:\n\n BUG: unable to handle page fault for address: ffff88817ae18880\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 4b53067 P4D 4b53067 PUD 0\n Oops: Oops: 0002 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 187 Comm: usleep Not tainted 7.0.10 #243 PREEMPT(full)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014\n Code: 24 78 00 00 00 00 48 89 ea 48 89 54 24 20 48 8b b4 24 b8 00 00 00 48 8b bc 24 b0 00 00 00 48 89 bc 24 80 00 00 00 48 83 ef 05 <65> 48 c1 3d 1f a8 b6 02 05 48 8b 15 f6 00 00 00 4c 89 3c 24 4c 89\n Call Trace:\n <TASK>\n ? find_held_lock\n ? exc_page_fault\n ? lock_release\n ? __x64_sys_clock_nanosleep\n ? lockdep_hardirqs_on_prepare\n ? trace_hardirqs_on\n __x64_sys_clock_nanosleep\n do_syscall_64\n ? exc_page_fault\n ? call_depth_return_thunk\n entry_SYSCALL_64_after_hwframe\n ...\n Kernel panic - not syncing: Fatal exception\n\nThis small reproducer allows to easily trigger the crash:\n\n # echo 'p __x64_sys_clock_nanosleep' > /sys/kernel/tracing/kprobe_events\n # echo 1 > /sys/kernel/tracing/events/kprobes/p___x64_sys_clock_nanosleep_0/enable\n # usleep 1\n\nMonitoring the crash under GDB points to the exact instruction in charge of\nincrementing the call depth:\n\n sarq $5, %gs:__x86_call_depth(%rip)\n\nThis instruction matches the one inserted by the ftrace_regs_caller from\nftrace_64.S. This emitted code was likely working fine until the introduction\nof\n\n 59bec00ace28 (\"x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()\"):\n\nit has made the call depth accounting addressing relative to $rip, instead of\nbeing based on an absolute address.\n\nAs this code exact location depends on where the trampoline lives in memory,\nthe corresponding displacement needs to be adjusted at runtime to actually\ncorrectly find the per-cpu __x86_call_depth value, otherwise the targeted\naddress is wrong, leading to the page fault seen above.\n\nFix the %rip-relative displacement of the copied CALL_DEPTH_ACCOUNT\ninstruction (from ftrace_regs_caller) by calling text_poke_apply_relocation(),\nas it is done for example by the x86 BPF JIT compiler through\nx86_call_depth_emit_accounting(). This corrects both CALL_DEPTH_ACCOUNT slots,\nin ftrace_caller and ftrace_regs_caller.\n\n [ bp: Massage. ]"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - With a dynamic ftrace/kprobe trampoline monitoring a receive-path function such as tcp_v4_rcv, an unauthenticated remote attacker reaches the faulty trampoline by sending a valid network packet.\nAC:H - Exploitation requires an affected Intel x86 platform using the non-default retbleed=stuff mitigation and an active dynamic trampoline on attacker-reachable code, conditions normally outside the attacker's control.\nPR:N - In a preconfigured network-monitoring deployment, the attacker only sends packets and needs no credentials. Creating the probe is privileged through tracefs DAC or init-namespace capabilities, but deployed observability infrastructure can establish it beforehand.\nUI:N - Tracing may be enabled automatically by deployed monitoring infrastructure, and no human action is required when the attacker triggers the traced function.\nS:U - The erroneous access and resulting compromise occur within the host kernel's existing security authority without crossing a VM, IOMMU, or other scope boundary.\nC:H - The stale displacement causes an out-of-bounds 8-byte read-modify-write that can land in mapped direct-map RAM on sufficiently large systems; corruption of kernel objects can plausibly enable code execution and arbitrary kernel-memory disclosure.\nI:H - The sarq instruction writes to unrelated direct-map memory, and repeated invocations can corrupt kernel objects or control data, potentially enabling kernel control-flow hijacking.\nA:H - The documented first invocation produces a supervisor write page fault followed by a fatal kernel oops and panic, causing complete system unavailability."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/ftrace.c"], "versions": [{"version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "8093442a2d1d4b42b9340a86023ccb2afb30b93a", "status": "affected", "versionType": "git"}, {"version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "d59cc66b702757e3c5a711e78a38583eac0c2738", "status": "affected", "versionType": "git"}, {"version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "9edff632ca216169846f8a63a5a3dc467e239c7a", "status": "affected", "versionType": "git"}, {"version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "a17dc12bfed8868e6a86f3b45c16065a70641acb", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/ftrace.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.35"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.0.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8093442a2d1d4b42b9340a86023ccb2afb30b93a"}, {"url": "https://git.kernel.org/stable/c/d59cc66b702757e3c5a711e78a38583eac0c2738"}, {"url": "https://git.kernel.org/stable/c/9edff632ca216169846f8a63a5a3dc467e239c7a"}, {"url": "https://git.kernel.org/stable/c/a17dc12bfed8868e6a86f3b45c16065a70641acb"}], "title": "x86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-64235", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:37:47.446270Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-476", "description": "CWE-476 NULL Pointer Dereference"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:28:16.189Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-64235", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:37:47.446270Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:37:48.132Z"}}], "cna": {"title": "x86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.1, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - With a dynamic ftrace/kprobe trampoline monitoring a receive-path function such as tcp_v4_rcv, an unauthenticated remote attacker reaches the faulty trampoline by sending a valid network packet.\nAC:H - Exploitation requires an affected Intel x86 platform using the non-default retbleed=stuff mitigation and an active dynamic trampoline on attacker-reachable code, conditions normally outside the attacker's control.\nPR:N - In a preconfigured network-monitoring deployment, the attacker only sends packets and needs no credentials. Creating the probe is privileged through tracefs DAC or init-namespace capabilities, but deployed observability infrastructure can establish it beforehand.\nUI:N - Tracing may be enabled automatically by deployed monitoring infrastructure, and no human action is required when the attacker triggers the traced function.\nS:U - The erroneous access and resulting compromise occur within the host kernel's existing security authority without crossing a VM, IOMMU, or other scope boundary.\nC:H - The stale displacement causes an out-of-bounds 8-byte read-modify-write that can land in mapped direct-map RAM on sufficiently large systems; corruption of kernel objects can plausibly enable code execution and arbitrary kernel-memory disclosure.\nI:H - The sarq instruction writes to unrelated direct-map memory, and repeated invocations can corrupt kernel objects or control data, potentially enabling kernel control-flow hijacking.\nA:H - The documented first invocation produces a supervisor write page fault followed by a fatal kernel oops and panic, causing complete system unavailability."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "8093442a2d1d4b42b9340a86023ccb2afb30b93a", "versionType": "git"}, {"status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "d59cc66b702757e3c5a711e78a38583eac0c2738", "versionType": "git"}, {"status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "9edff632ca216169846f8a63a5a3dc467e239c7a", "versionType": "git"}, {"status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "lessThan": "a17dc12bfed8868e6a86f3b45c16065a70641acb", "versionType": "git"}], "programFiles": ["arch/x86/kernel/ftrace.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"status": "unaffected", "version": "0", "lessThan": "6.9", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.93", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.35", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.12", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/x86/kernel/ftrace.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/8093442a2d1d4b42b9340a86023ccb2afb30b93a"}, {"url": "https://git.kernel.org/stable/c/d59cc66b702757e3c5a711e78a38583eac0c2738"}, {"url": "https://git.kernel.org/stable/c/9edff632ca216169846f8a63a5a3dc467e239c7a"}, {"url": "https://git.kernel.org/stable/c/a17dc12bfed8868e6a86f3b45c16065a70641acb"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines\n\nWith CONFIG_CALL_DEPTH_TRACKING enabled on an x86 retbleed-affected platform\n(eg: Skylake), with retbleed=stuff, registering a dynamic ftrace trampoline\ncrashes on the first call into the traced function:\n\n BUG: unable to handle page fault for address: ffff88817ae18880\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 4b53067 P4D 4b53067 PUD 0\n Oops: Oops: 0002 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 187 Comm: usleep Not tainted 7.0.10 #243 PREEMPT(full)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014\n Code: 24 78 00 00 00 00 48 89 ea 48 89 54 24 20 48 8b b4 24 b8 00 00 00 48 8b bc 24 b0 00 00 00 48 89 bc 24 80 00 00 00 48 83 ef 05 <65> 48 c1 3d 1f a8 b6 02 05 48 8b 15 f6 00 00 00 4c 89 3c 24 4c 89\n Call Trace:\n <TASK>\n ? find_held_lock\n ? exc_page_fault\n ? lock_release\n ? __x64_sys_clock_nanosleep\n ? lockdep_hardirqs_on_prepare\n ? trace_hardirqs_on\n __x64_sys_clock_nanosleep\n do_syscall_64\n ? exc_page_fault\n ? call_depth_return_thunk\n entry_SYSCALL_64_after_hwframe\n ...\n Kernel panic - not syncing: Fatal exception\n\nThis small reproducer allows to easily trigger the crash:\n\n # echo 'p __x64_sys_clock_nanosleep' > /sys/kernel/tracing/kprobe_events\n # echo 1 > /sys/kernel/tracing/events/kprobes/p___x64_sys_clock_nanosleep_0/enable\n # usleep 1\n\nMonitoring the crash under GDB points to the exact instruction in charge of\nincrementing the call depth:\n\n sarq $5, %gs:__x86_call_depth(%rip)\n\nThis instruction matches the one inserted by the ftrace_regs_caller from\nftrace_64.S. This emitted code was likely working fine until the introduction\nof\n\n 59bec00ace28 (\"x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()\"):\n\nit has made the call depth accounting addressing relative to $rip, instead of\nbeing based on an absolute address.\n\nAs this code exact location depends on where the trampoline lives in memory,\nthe corresponding displacement needs to be adjusted at runtime to actually\ncorrectly find the per-cpu __x86_call_depth value, otherwise the targeted\naddress is wrong, leading to the page fault seen above.\n\nFix the %rip-relative displacement of the copied CALL_DEPTH_ACCOUNT\ninstruction (from ftrace_regs_caller) by calling text_poke_apply_relocation(),\nas it is done for example by the x86 BPF JIT compiler through\nx86_call_depth_emit_accounting(). This corrects both CALL_DEPTH_ACCOUNT slots,\nin ftrace_caller and ftrace_regs_caller.\n\n [ bp: Massage. ]"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.93", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.35", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0.12", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1", "versionStartIncluding": "6.9"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:40:13.850Z"}}}, "cveMetadata": {"cveId": "CVE-2026-64235", "state": "PUBLISHED", "dateUpdated": "2026-10-16T15:42:27.004Z", "dateReserved": "2026-07-19T15:36:31.771Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-07-24T15:27:40.814Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/x86/kernel/ftrace.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8093442a2d1d4b42b9340a86023ccb2afb30b93a", "status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "versionType": "git"}, {"lessThan": "d59cc66b702757e3c5a711e78a38583eac0c2738", "status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "versionType": "git"}, {"lessThan": "9edff632ca216169846f8a63a5a3dc467e239c7a", "status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "versionType": "git"}, {"lessThan": "a17dc12bfed8868e6a86f3b45c16065a70641acb", "status": "affected", "version": "59bec00ace28d565ae0a68b23063ef3b961d82d5", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/x86/kernel/ftrace.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.93", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.35", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.12", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "639BA3A3-BBF8-4E67-95F9-1162C6691807", "versionEndExcluding": "6.12.93", "versionStartIncluding": "6.9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0FCCB23A-7629-4386-93B6-B119237C4382", "versionEndExcluding": "6.18.35", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9161A938-0FA8-44BC-95FE-C5A271601AB3", "versionEndExcluding": "7.0.12", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*", "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines\n\nWith CONFIG_CALL_DEPTH_TRACKING enabled on an x86 retbleed-affected platform\n(eg: Skylake), with retbleed=stuff, registering a dynamic ftrace trampoline\ncrashes on the first call into the traced function:\n\n BUG: unable to handle page fault for address: ffff88817ae18880\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 4b53067 P4D 4b53067 PUD 0\n Oops: Oops: 0002 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 187 Comm: usleep Not tainted 7.0.10 #243 PREEMPT(full)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014\n Code: 24 78 00 00 00 00 48 89 ea 48 89 54 24 20 48 8b b4 24 b8 00 00 00 48 8b bc 24 b0 00 00 00 48 89 bc 24 80 00 00 00 48 83 ef 05 <65> 48 c1 3d 1f a8 b6 02 05 48 8b 15 f6 00 00 00 4c 89 3c 24 4c 89\n Call Trace:\n <TASK>\n ? find_held_lock\n ? exc_page_fault\n ? lock_release\n ? __x64_sys_clock_nanosleep\n ? lockdep_hardirqs_on_prepare\n ? trace_hardirqs_on\n __x64_sys_clock_nanosleep\n do_syscall_64\n ? exc_page_fault\n ? call_depth_return_thunk\n entry_SYSCALL_64_after_hwframe\n ...\n Kernel panic - not syncing: Fatal exception\n\nThis small reproducer allows to easily trigger the crash:\n\n # echo 'p __x64_sys_clock_nanosleep' > /sys/kernel/tracing/kprobe_events\n # echo 1 > /sys/kernel/tracing/events/kprobes/p___x64_sys_clock_nanosleep_0/enable\n # usleep 1\n\nMonitoring the crash under GDB points to the exact instruction in charge of\nincrementing the call depth:\n\n sarq $5, %gs:__x86_call_depth(%rip)\n\nThis instruction matches the one inserted by the ftrace_regs_caller from\nftrace_64.S. This emitted code was likely working fine until the introduction\nof\n\n 59bec00ace28 (\"x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()\"):\n\nit has made the call depth accounting addressing relative to $rip, instead of\nbeing based on an absolute address.\n\nAs this code exact location depends on where the trampoline lives in memory,\nthe corresponding displacement needs to be adjusted at runtime to actually\ncorrectly find the per-cpu __x86_call_depth value, otherwise the targeted\naddress is wrong, leading to the page fault seen above.\n\nFix the %rip-relative displacement of the copied CALL_DEPTH_ACCOUNT\ninstruction (from ftrace_regs_caller) by calling text_poke_apply_relocation(),\nas it is done for example by the x86 BPF JIT compiler through\nx86_call_depth_emit_accounting(). This corrects both CALL_DEPTH_ACCOUNT slots,\nin ftrace_caller and ftrace_regs_caller.\n\n [ bp: Massage. ]"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: x86/ftrace: Reubicar referencias percpu relativas a %rip en trampolines din\u00e1micos Con CONFIG_CALL_DEPTH_TRACKING habilitado en una plataforma x86 afectada por retbleed (ej: Skylake), con retbleed=stuff, registrar un trampoline ftrace din\u00e1mico falla en la primera llamada a la funci\u00f3n rastreada: BUG: no se puede manejar el fallo de p\u00e1gina para la direcci\u00f3n: ffff88817ae18880 #PF: acceso de escritura de supervisor en modo kernel #PF: error_code(0x0002) - p\u00e1gina no presente PGD 4b53067 P4D 4b53067 PUD 0 Oops: Oops: 0002 [#1] SMP PTI CPU: 3 UID: 0 PID: 187 Comm: usleep No contaminado 7.0.10 #243 PREEMPT(full) Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 Code: 24 78 00 00 00 00 48 89 ea 48 89 54 24 20 48 8b b4 24 b8 00 00 00 48 8b bc 24 b0 00 00 00 48 89 bc 24 80 00 00 00 48 83 ef 05 menor que 65mayor que 48 c1 3d 1f a8 b6 02 05 48 8b 15 f6 00 00 00 4c 89 3c 24 4c 89 Traza de Llamadas: [TAREA] ? find_held_lock ? exc_page_fault ? lock_release ? __x64_sys_clock_nanosleep ? lockdep_hardirqs_on_prepare ? trace_hardirqs_on __x64_sys_clock_nanosleep do_syscall_64 ? exc_page_fault ? call_depth_return_thunk entry_SYSCALL_64_after_hwframe ... P\u00e1nico del kernel - no sincronizando: Excepci\u00f3n fatal Este peque\u00f1o reproductor permite activar f\u00e1cilmente el fallo: # echo \u2019p __x64_sys_clock_nanosleep\u2019 > /sys/kernel/tracing/kprobe_events # echo 1 > /sys/kernel/tracing/events/kprobes/p___x64_sys_clock_nanosleep_0/enable # usleep 1 Monitorizar el fallo bajo GDB apunta a la instrucci\u00f3n exacta encargada de incrementar la profundidad de llamada: sarq $5, %gs:__x86_call_depth(%rip) Esta instrucci\u00f3n coincide con la insertada por el ftrace_regs_caller de ftrace_64.S. Este c\u00f3digo emitido probablemente funcionaba bien hasta la introducci\u00f3n de 59bec00ace28 (\u2019x86/percpu: Introducir direccionamiento relativo a %rip en PER_CPU_VAR()\u2019): ha hecho que el direccionamiento de la contabilidad de la profundidad de llamada sea relativo a $rip, en lugar de basarse en una direcci\u00f3n absoluta. Como la ubicaci\u00f3n exacta de este c\u00f3digo depende de d\u00f3nde reside el trampoline en memoria, el desplazamiento correspondiente necesita ser ajustado en tiempo de ejecuci\u00f3n para encontrar realmente de forma correcta el valor __x86_call_depth por CPU; de lo contrario, la direcci\u00f3n objetivo es incorrecta, lo que lleva al fallo de p\u00e1gina visto anteriormente. Corregir el desplazamiento relativo a %rip de la instrucci\u00f3n CALL_DEPTH_ACCOUNT copiada (de ftrace_regs_caller) llamando a text_poke_apply_relocation(), como se hace, por ejemplo, por el compilador JIT BPF de x86 a trav\u00e9s de x86_call_depth_emit_accounting(). Esto corrige ambas ranuras CALL_DEPTH_ACCOUNT, en ftrace_caller y ftrace_regs_caller. [ bp: Ajustes. ]"}], "id": "CVE-2026-64235", "lastModified": "2026-11-08T16:10:00.183", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-64235", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:37:47.446270Z", "version": "2.0.3"}}]}, "published": "2026-07-24T16:16:52.737", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8093442a2d1d4b42b9340a86023ccb2afb30b93a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9edff632ca216169846f8a63a5a3dc467e239c7a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/a17dc12bfed8868e6a86f3b45c16065a70641acb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d59cc66b702757e3c5a711e78a38583eac0c2738"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-476"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: x86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines", "id": "2506792", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2506792"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-64235", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64235\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64235\nhttps://lore.kernel.org/linux-cve-announce/2026072440-CVE-2026-64235-6bc3@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[59bec00ace28d565ae0a68b23063ef3b961d82d5,8093442a2d1d4b42b9340a86023ccb2afb30b93a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[59bec00ace28d565ae0a68b23063ef3b961d82d5,d59cc66b702757e3c5a711e78a38583eac0c2738)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[59bec00ace28d565ae0a68b23063ef3b961d82d5,9edff632ca216169846f8a63a5a3dc467e239c7a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[59bec00ace28d565ae0a68b23063ef3b961d82d5,a17dc12bfed8868e6a86f3b45c16065a70641acb)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "6.9"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0.0.0,6.9.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.93,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.35,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.12,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-24T21:45:02.737758+00:00", "updated": "2026-10-23T00:15:13.792401+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}