From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B7173403E3 for ; Sat, 15 Aug 2026 06:07:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786774069; cv=none; b=nTV6Bs0Ml/OHupz+HeFMRipctLv3SqcegcTdzT4P8xAT+8cJDqxaw1GQRK3CLgLNN9jd1CniAmq7ZwvpcBFn5p9LxdS7eKJZ6g+VlwBBlC5btVHxtFxMh7aZF+AoXZqE/5njEV3ObUXBjiUay3SsAd2aC5W77pWyxFOxUC1Y03Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786774069; c=relaxed/simple; bh=NjfnGwnVDYSkNXD23x7XYF7NJPYrTwIfawrXH0S6nQQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nwoFkoojMYPEblIA3ow4E9yMVtufbQVlVBAeEi09XzUSKQihVyGPWDBrv/UWQD3yaGCcckhQ3YPd6lRLf9e4EJbXv6xXq69S7J0Yhs01Z9bTsmt94uc4/tXFbEMiKhk4EQ+zDEU5+ZKZwJ2K3cgpBU0yUxfo6lRIEy+59BEZUTE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SV3ad8jO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SV3ad8jO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 603351F000E9; Sat, 15 Aug 2026 06:07:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786774067; bh=Abiz/ewgcx2JxkpDufrmAvJJkdCZxF3ORGLFAsFqdtg=; h=From:To:Cc:Subject:Date:Reply-To; b=SV3ad8jOPwDk0/4OYdwtCGquNmkGgiFEHZuGWg7QDjsEi8O/udp+/hjgemuxdsB5X eCDfAc8vUTNDat0c2SJk+f/IQgmkbJaa8OxCSRh8q5O+nCMaI45s4VTW2IAWaNKZ/s LD4AcZ8YDJkuAd/XSRJnelNPCPCb5HY2yD3tPsTw= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-72028: riscv: probes: save original sp in rethook trampoline Date: Sat, 15 Aug 2026 15:01:47 +0900 Message-ID: <2026081511-CVE-2026-72028-749b@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3671; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=hsXo9e4tIZfcmtrTNtw3/TjtVtWEcCCaKuRZo8FbEfk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNDMt3SgWpOK9TvXgpKnfhNq9VZinTFn++sffB+ryZO zrsT3sKdMSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEVBYzLNgnUHFhYnP51TR5 BTNFma+Zm/i2HWKYK/hg06HFZxK9PKaqncm02lHywSfxPQA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== 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 ... [] regs_get_kernel_stack_nth+0x26/0x38 [] process_fetch_insn+0x3ee/0x760 [] kretprobe_trace_func+0x116/0x1f0 [] kretprobe_dispatcher+0x4a/0x58 [] kretprobe_rethook_handler+0x5e/0x90 [] rethook_trampoline_handler+0x70/0x108 [] arch_rethook_trampoline_callback+0x12/0x1c [] arch_rethook_trampoline+0x48/0x94 [] 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] The Linux kernel CVE team has assigned CVE-2026-72028 to this issue. Affected and fixed versions =========================== Issue introduced in 5.12 with commit c22b0bcb1dd024cb9caad9230e3a387d8b061df5 and fixed in 6.6.145 with commit 5da5cf48a432e30ded8d58087854e5383a36eff1 Issue introduced in 5.12 with commit c22b0bcb1dd024cb9caad9230e3a387d8b061df5 and fixed in 6.12.97 with commit c386e1c591d72eab58ee2e69105c8cbc70928857 Issue introduced in 5.12 with commit c22b0bcb1dd024cb9caad9230e3a387d8b061df5 and fixed in 6.18.40 with commit 2faf0198168d2017cb528a79f76c560fda3b6e94 Issue introduced in 5.12 with commit c22b0bcb1dd024cb9caad9230e3a387d8b061df5 and fixed in 7.1.5 with commit 91b4d76dd07f1a1f20f73dfebb42ba04ac911a56 Issue introduced in 5.12 with commit c22b0bcb1dd024cb9caad9230e3a387d8b061df5 and fixed in 7.2-rc2 with commit bc7b086a45521a986a49045907f017e3e46c763e Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-72028 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: arch/riscv/kernel/probes/rethook_trampoline.S Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: 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