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Fri, 13 Nov 2026 20:50:18 +0000 (GMT) Received: from li-43857255-d5e6-4659-90f1-fc5cee4750ad.ibm.com (unknown [9.61.146.174]) by smtpav06.wdc07v.mail.ibm.com (Postfix) with ESMTP; Fri, 13 Nov 2026 20:50:18 +0000 (GMT) Message-ID: <0225c3dbe0f73652994374660500973512203182.camel@linux.ibm.com> Subject: Re: [PATCH v2 2/3] ima: keep kexec dump state tied to installed image From: Mimi Zohar To: =?ISO-8859-1?Q?J=E9r=E9my?= Jean , Andrew Morton , Baoquan He , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Roberto Sassu , Dmitry Kasatkin Cc: Eric Snowberg , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, stable@vger.kernel.org In-Reply-To: <20261112125246.2715174-4-Jeremy.Jean@oss.cyber.gouv.fr> References: <20261112125246.2715174-2-Jeremy.Jean@oss.cyber.gouv.fr> <20261112125246.2715174-4-Jeremy.Jean@oss.cyber.gouv.fr> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 13 Nov 2026 15:50:18 -0500 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Evolution 3.58.3 (3.58.3-2.fc43) X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYxMTEzMDA4MSBTYWx0ZWRfX8WbvkQga/2l2 cLkruBDGzRlLiWFBwoCd5qvDtr3poOSlHYnCUZRtW/UODWTwvYJav2eMzoeiL55LseagzzHQwmN ouOBiupllJbQxcgrbV3pWmENeHOay4qAojUzyGJic32RAQbOlEuz52hw7dFs2vLBYWwDD5t+dc4 3gZxGdDERa55KlxKTODBr4tSIH24eFLQboycGYYBJORscQktndsaEZPUfjM/IyPDhc0ShQpkug3 p6TstV3zhmeV11/6KvF5deIBR+Rd2YJjEL5u4Rky8jRGBC3sS3cpGxtALnuy8ZAZ4RM7Gii7usw vF7mBjwuZcfTDCI7OKFpJHVgMrhhv+xdzDEgpCGQut1kbCrNIn/jbXMgp8m5FQn2G1yNc8dyT7t BjVHsVJPAQ+udpWyR9pHhxd1hGHCQw5HNOXxEg/IAtvo/Yc+EoO/YnqvoVG/MGOmbWGtGVWq0fc hGxnlgmx0KIrGkGjbyg== X-Proofpoint-ORIG-GUID: NLoUN-Wj5mEwJ2D7Y2HAV6ofnjhrOBS1 X-Proofpoint-Spam-Info: AW1haW4tMjYxMTEzMDA4MSBTYWx0ZWRfX4I02K66mSj8y 9/+wMKGKDNGJpDTtgpfOVDhZquEPv2BK3+Z/3Wdirjxa+79ELmZv43LTAwOHkLNV0l62RxRPLlv edjAlQztWjL+nvb86QKzpwbvOVdUNAE= X-Authority-Analysis: v=2.4 cv=euZKXYpX c=1 sm=1 tr=0 ts=6af7780f cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=zJRp6_cAMcgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=YQ5yl0S3xsvPwjc2iwwA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: edZdwUNg5sz7B7bLE53BPf8m9G9KJhvW X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.138,FMLib:17.12.100.49 definitions=2026-11-13_06,2026-11-11_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 clxscore=1015 suspectscore=0 spamscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 impostorscore=0 adultscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2611040001 definitions=main-2611130081 On Thu, 2026-11-12 at 12:52 +0000, J=C3=A9r=C3=A9my Jean wrote: [...] > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/= ima_kexec.c > index 0d845693a1f7..3aa8b1096f81 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -35,7 +35,8 @@ static void ima_free_kexec_file_buf(struct seq_file *sf= ) > sf->count =3D 0; > } > =20 > -void ima_measure_kexec_event(const char *event_name) > +static void ima_measure_kexec_event_size(const char *event_name, > + size_t segment_size) > { > char ima_kexec_event[IMA_KEXEC_EVENT_LEN]; > size_t buf_size =3D 0; > @@ -48,35 +49,26 @@ void ima_measure_kexec_event(const char *event_name) > n =3D scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN, > "kexec_segment_size=3D%lu;ima_binary_runtime_size=3D%lu;" > "ima_runtime_measurements_count=3D%ld;", > - kexec_segment_size, buf_size, len); > + segment_size, buf_size, len); > =20 > ima_measure_critical_data("ima_kexec", event_name, ima_kexec_event, n, = false, NULL, 0); > } > =20 > -static int ima_alloc_kexec_file_buf(size_t segment_size) > +void ima_measure_kexec_event(const char *event_name) > { > - /* > - * kexec 'load' may be called multiple times. > - * Free and realloc the buffer only if the segment_size is > - * changed from the previous kexec 'load' call. > - */ > - if (ima_kexec_file.buf && ima_kexec_file.size =3D=3D segment_size) > - goto out; > + ima_measure_kexec_event_size(event_name, kexec_segment_size); > +} > =20 > - ima_free_kexec_file_buf(&ima_kexec_file); > +static int ima_alloc_kexec_file_buf(struct kimage *image, size_t segment= _size) > +{ > + if (ima_kexec_file.buf && ima_kexec_file.size =3D=3D segment_size) > + return 0; Please don't drop the comment. The crux of the problem is that a kexec load may fail, so the installed image's state shouldn't change until the new image is installed. To keep this patch as small as possible, could the event-size change be a separate patch, applied after this one? That would make the overflow fix easier to review and backport. Suggested comment: * kexec 'load' may be called multiple times, and a load may fail. * ima_kexec_file.size is the segment size of the installed image and * is only set in ima_kexec_post_load(). Reuse the installed buffer if * the segment_size is unchanged, otherwise stage a new one on the image. Mimi > =20 > /* segment size can't change between kexec load and execute */ > - ima_kexec_file.buf =3D vmalloc(segment_size); > - if (!ima_kexec_file.buf) > + image->ima_buffer =3D vmalloc(segment_size); > + if (!image->ima_buffer) > return -ENOMEM; > =20 > - ima_kexec_file.size =3D segment_size; > - > -out: > - ima_kexec_file.read_pos =3D 0; > - ima_kexec_file.count =3D sizeof(struct ima_kexec_hdr); /* reserved spac= e */ > - ima_measure_kexec_event("kexec_load"); > - > return 0; > } > =20