CVE-2026-72028

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]

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/2faf0198168d2017cb528a79f76c560fda3b6e94
https://git.kernel.org/stable/c/5da5cf48a432e30ded8d58087854e5383a36eff1
https://git.kernel.org/stable/c/91b4d76dd07f1a1f20f73dfebb42ba04ac911a56
https://git.kernel.org/stable/c/bc7b086a45521a986a49045907f017e3e46c763e
https://git.kernel.org/stable/c/c386e1c591d72eab58ee2e69105c8cbc70928857

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-15 06:21

Updated : 2026-08-17 06:18

NVD link : CVE-2026-72028

Mitre link : CVE-2026-72028

CVE.ORG link : CVE-2026-72028

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2026-72028", "cveTags": [], "metrics": {}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5", "lessThan": "5da5cf48a432e30ded8d58087854e5383a36eff1", "versionType": "git"}, {"status": "affected", "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5", "lessThan": "c386e1c591d72eab58ee2e69105c8cbc70928857", "versionType": "git"}, {"status": "affected", "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5", "lessThan": "2faf0198168d2017cb528a79f76c560fda3b6e94", "versionType": "git"}, {"status": "affected", "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5", "lessThan": "91b4d76dd07f1a1f20f73dfebb42ba04ac911a56", "versionType": "git"}, {"status": "affected", "version": "c22b0bcb1dd024cb9caad9230e3a387d8b061df5", "lessThan": "bc7b086a45521a986a49045907f017e3e46c763e", "versionType": "git"}], "programFiles": ["arch/riscv/kernel/probes/rethook_trampoline.S"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"status": "unaffected", "version": "0", "lessThan": "5.12", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.145", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.97", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.40", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.5", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/riscv/kernel/probes/rethook_trampoline.S"], "defaultStatus": "affected"}]}], "published": "2026-08-15T06:21:01.953", "references": [{"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", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "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 'r n_tty_write $stack0' > dynamic_events\n$ echo 1 > events/kprobes/enable\nUnable to handle kernel paging request at virtual address 0000000200000128\n...\n[<ffffffff80016d16>] regs_get_kernel_stack_nth+0x26/0x38\n[<ffffffff80177196>] process_fetch_insn+0x3ee/0x760\n[<ffffffff80177836>] kretprobe_trace_func+0x116/0x1f0\n[<ffffffff8017795a>] kretprobe_dispatcher+0x4a/0x58\n[<ffffffff8013572e>] kretprobe_rethook_handler+0x5e/0x90\n[<ffffffff80180838>] rethook_trampoline_handler+0x70/0x108\n[<ffffffff8001ba32>] arch_rethook_trampoline_callback+0x12/0x1c\n[<ffffffff8001ba84>] arch_rethook_trampoline+0x48/0x94\n[<ffffffff8067872a>] tty_write+0x1a/0x30\n\nIn regs_get_kernel_stack_nth, regs->sp 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's 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'ed stable]"}], "lastModified": "2026-08-17T06:18:00.533", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}