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[122.63.64.114]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2bf23b011d3sm2617945ad.52.2026.05.28.20.35.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2026 20:35:46 -0700 (PDT) From: Tao Liu To: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Tao Liu Subject: [PATCH] riscv: Fix a NULL pointer reference in machine_kexec_prepare Date: Fri, 29 May 2026 15:27:40 +1200 Message-ID: <20260529032739.13264-2-ltao@redhat.com> X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" A NULL pointer reference issue is noticed in riscv's machine_kexec_prepare, where image->segment[i].buf might be NULL and copied unchecked. The NULL buf comes from security/integrity/ima/ima_kexec.c: ima_add_kexec_buffer(), where kbuf is added by kexec_add_buffer(), but kbuf.buffer is NULL. Fix this by simply adding a check before copy. Signed-off-by: Tao Liu --- arch/riscv/kernel/machine_kexec.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_= kexec.c index 2306ce3e5f22..d81d576f9cb5 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -41,6 +41,9 @@ machine_kexec_prepare(struct kimage *image) if (image->segment[i].memsz <=3D sizeof(fdt)) continue; =20 + if (image->segment[i].buf =3D=3D NULL) + continue; + if (image->file_mode) memcpy(&fdt, image->segment[i].buf, sizeof(fdt)); else if (copy_from_user(&fdt, image->segment[i].buf, sizeof(fdt))) --=20 2.47.0