{"id":"CVE-2025-40112","state":"PUBLISHED","title":"sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsparc: fix accurate exception reporting in copy_{from_to}_user for Niagara\n\nThe referenced commit introduced exception handlers on user-space memory\nreferences in copy_from_user and copy_to_user. These handlers return from\nthe respective function and calculate the remaining bytes left to copy\nusing the current register contents. This commit fixes a couple of bad\ncalculations and a broken epilogue in the exception handlers. This will\nprevent crashes and ensure correct return values of copy_from_user and\ncopy_to_user in the faulting case. The behaviour of memcpy stays unchanged.","publishedAt":"2025-11-12T10:23:16.690Z","updatedAt":"2026-08-05T12:07:52.886Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"05440320ea3e249d5f984918f2bf51210c1a7c03","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"7823fc4d8ab5e57f8db7806ff2530c03c166c4bb","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"37547d8e6eba87507279ee3dfddfd9dc46335454","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"a365ee556e45f780ee322b349a06efdad0c1458f","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"8cdeb5e482d3fdce7e825444b6ca3865e24c0228","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"a90ce516a73dbe087f9bf3dbf311301a58d125c6","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"088c5098ec6d6b0396edfbf3dad3e81de8469c1c","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"0b67c8fc10b13a9090340c5f8a37d308f4e1571c","versionType":"git"},{"version":"bfc8be6593097cb074d3912ba2f27565cfbb7d6e","status":"affected","versionType":"git"},{"version":"a15859f9d8396cce7c55ccdb7e75f70f14cbc349","status":"affected","versionType":"git"},{"version":"4.4.34","status":"affected","lessThan":"4.5","versionType":"semver"},{"version":"4.8.10","status":"affected","lessThan":"4.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/sparc/lib/NGmemcpy.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"5.4.301","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.246","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.195","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.156","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.112","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.53","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.3","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/sparc/lib/NGmemcpy.S"]}],"references":["https://git.kernel.org/stable/c/05440320ea3e249d5f984918f2bf51210c1a7c03","https://git.kernel.org/stable/c/7823fc4d8ab5e57f8db7806ff2530c03c166c4bb","https://git.kernel.org/stable/c/37547d8e6eba87507279ee3dfddfd9dc46335454","https://git.kernel.org/stable/c/a365ee556e45f780ee322b349a06efdad0c1458f","https://git.kernel.org/stable/c/8cdeb5e482d3fdce7e825444b6ca3865e24c0228","https://git.kernel.org/stable/c/a90ce516a73dbe087f9bf3dbf311301a58d125c6","https://git.kernel.org/stable/c/088c5098ec6d6b0396edfbf3dad3e81de8469c1c","https://git.kernel.org/stable/c/0b67c8fc10b13a9090340c5f8a37d308f4e1571c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40112.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40112","state":"PUBLISHED","datePublished":"2025-11-12T10:23:16.690Z","dateUpdated":"2026-08-05T12:07:52.886Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.167Z"},"containers":{"cna":{"title":"sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsparc: fix accurate exception reporting in copy_{from_to}_user for Niagara\n\nThe referenced commit introduced exception handlers on user-space memory\nreferences in copy_from_user and copy_to_user. These handlers return from\nthe respective function and calculate the remaining bytes left to copy\nusing the current register contents. This commit fixes a couple of bad\ncalculations and a broken epilogue in the exception handlers. This will\nprevent crashes and ensure correct return values of copy_from_user and\ncopy_to_user in the faulting case. The behaviour of memcpy stays unchanged."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"05440320ea3e249d5f984918f2bf51210c1a7c03","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"7823fc4d8ab5e57f8db7806ff2530c03c166c4bb","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"37547d8e6eba87507279ee3dfddfd9dc46335454","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"a365ee556e45f780ee322b349a06efdad0c1458f","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"8cdeb5e482d3fdce7e825444b6ca3865e24c0228","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"a90ce516a73dbe087f9bf3dbf311301a58d125c6","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"088c5098ec6d6b0396edfbf3dad3e81de8469c1c","versionType":"git"},{"version":"7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e","status":"affected","lessThan":"0b67c8fc10b13a9090340c5f8a37d308f4e1571c","versionType":"git"},{"version":"bfc8be6593097cb074d3912ba2f27565cfbb7d6e","status":"affected","versionType":"git"},{"version":"a15859f9d8396cce7c55ccdb7e75f70f14cbc349","status":"affected","versionType":"git"},{"version":"4.4.34","status":"affected","lessThan":"4.5","versionType":"semver"},{"version":"4.8.10","status":"affected","lessThan":"4.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/sparc/lib/NGmemcpy.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"5.4.301","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.246","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.195","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.156","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.112","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.53","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.3","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/sparc/lib/NGmemcpy.S"]}],"references":[{"url":"https://git.kernel.org/stable/c/05440320ea3e249d5f984918f2bf51210c1a7c03"},{"url":"https://git.kernel.org/stable/c/7823fc4d8ab5e57f8db7806ff2530c03c166c4bb"},{"url":"https://git.kernel.org/stable/c/37547d8e6eba87507279ee3dfddfd9dc46335454"},{"url":"https://git.kernel.org/stable/c/a365ee556e45f780ee322b349a06efdad0c1458f"},{"url":"https://git.kernel.org/stable/c/8cdeb5e482d3fdce7e825444b6ca3865e24c0228"},{"url":"https://git.kernel.org/stable/c/a90ce516a73dbe087f9bf3dbf311301a58d125c6"},{"url":"https://git.kernel.org/stable/c/088c5098ec6d6b0396edfbf3dad3e81de8469c1c"},{"url":"https://git.kernel.org/stable/c/0b67c8fc10b13a9090340c5f8a37d308f4e1571c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The fault must occur on the calling process's own user-space buffer during a syscall, so the attacker needs local execution to issue syscalls with a deliberately unmapped/PROT_NONE user address. No remote or adjacent-network path can drive copy_from_user/copy_to_user faults on behalf of another task.\nAC:L - The attacker fully controls every precondition — mmap a buffer, punch a PROT_NONE/unmapped page, and pick the length and alignment that steer the copy into the buggy 16-byte or unaligned loop; the broken __restore_asi epilogue is hit on every fault regardless. No race, no memory-layout luck, and the Niagara copy routines are auto-selected by CPU type with no special kernel config.\nPR:L - Any unprivileged local user can pass a partially-invalid user pointer to ordinary syscalls such as read(), write(), sendmsg() or ioctl(); no capability, namespace or filesystem privilege is involved.\nUI:N - The attacking process triggers the faulting copy entirely on its own via a syscall; no action by another user or administrator is needed.\nS:U - The corruption is confined to the kernel of the running system — no hypervisor, IOMMU or sandbox boundary is crossed.\nC:H - The under-reported remainder leaves 8–16 bytes of the kernel destination buffer unzeroed by _inline_copy_from_user()'s memset and treated as valid user data, repeatedly leaking stale kernel heap/stack contents into buffers that syscalls process or write back; the missing register-window restore additionally exposes kernel pointers as the copy's return value.\nI:H - The dead `restore` makes raw_copy_from_user return a destination pointer instead of a byte count, so memset(to + (n - res), 0, res) becomes an unbounded out-of-bounds kernel write, and the unpopped register window leaves the caller with a corrupted %sp/%fp and a wrong saved return address — memory corruption with attacker-influenced pointers and hijackable control flow.\nA:H - Returning without restoring the register window desynchronizes the entire SPARC window stack and the caller's stack frame, and the giant memset length guarantees a wild write; the result is an immediate kernel oops/panic on every triggered fault, trivially repeatable by an unprivileged user."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:07:52.886Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"5.4.301"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"5.10.246"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"5.15.195"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.1.156"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.6.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.12.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.17.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8.10"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}