{"id":"CVE-2026-72028","state":"PUBLISHED","title":"riscv: probes: save original sp in rethook trampoline","description":"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]","publishedAt":"2026-08-15T05:51:51.868Z","updatedAt":"2026-10-30T12:28:45.873Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"d21109fe4a55247094f913773a334772907cd016","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"5da5cf48a432e30ded8d58087854e5383a36eff1","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"c386e1c591d72eab58ee2e69105c8cbc70928857","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"2faf0198168d2017cb528a79f76c560fda3b6e94","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"91b4d76dd07f1a1f20f73dfebb42ba04ac911a56","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"bc7b086a45521a986a49045907f017e3e46c763e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kernel/probes/rethook_trampoline.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kernel/probes/rethook_trampoline.S"]}],"references":["https://git.kernel.org/stable/c/d21109fe4a55247094f913773a334772907cd016","https://git.kernel.org/stable/c/5da5cf48a432e30ded8d58087854e5383a36eff1","https://git.kernel.org/stable/c/c386e1c591d72eab58ee2e69105c8cbc70928857","https://git.kernel.org/stable/c/2faf0198168d2017cb528a79f76c560fda3b6e94","https://git.kernel.org/stable/c/91b4d76dd07f1a1f20f73dfebb42ba04ac911a56","https://git.kernel.org/stable/c/bc7b086a45521a986a49045907f017e3e46c763e"],"weaknesses":[],"ingestedAt":"2026-10-30T12:46:06.359Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72028.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72028","state":"PUBLISHED","datePublished":"2026-08-15T05:51:51.868Z","dateUpdated":"2026-10-30T12:28:45.873Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.901Z"},"containers":{"cna":{"title":"riscv: probes: save original sp in rethook trampoline","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]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"d21109fe4a55247094f913773a334772907cd016","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"5da5cf48a432e30ded8d58087854e5383a36eff1","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"c386e1c591d72eab58ee2e69105c8cbc70928857","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"2faf0198168d2017cb528a79f76c560fda3b6e94","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"91b4d76dd07f1a1f20f73dfebb42ba04ac911a56","versionType":"git"},{"version":"c22b0bcb1dd024cb9caad9230e3a387d8b061df5","status":"affected","lessThan":"bc7b086a45521a986a49045907f017e3e46c763e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kernel/probes/rethook_trampoline.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kernel/probes/rethook_trampoline.S"]}],"references":[{"url":"https://git.kernel.org/stable/c/d21109fe4a55247094f913773a334772907cd016"},{"url":"https://git.kernel.org/stable/c/5da5cf48a432e30ded8d58087854e5383a36eff1"},{"url":"https://git.kernel.org/stable/c/c386e1c591d72eab58ee2e69105c8cbc70928857"},{"url":"https://git.kernel.org/stable/c/2faf0198168d2017cb528a79f76c560fda3b6e94"},{"url":"https://git.kernel.org/stable/c/91b4d76dd07f1a1f20f73dfebb42ba04ac911a56"},{"url":"https://git.kernel.org/stable/c/bc7b086a45521a986a49045907f017e3e46c763e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:28:45.873Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}