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Thu, 11 Jun 2026 10:48:51 +0000 (GMT) Received: from p-imbrenda.ehn-de.ibm.com (unknown [9.224.75.30]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 11 Jun 2026 10:48:51 +0000 (GMT) From: Claudio Imbrenda To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, david@kernel.org, seiden@linux.ibm.com, nrb@linux.ibm.com, schlameuss@linux.ibm.com, gra@linux.ibm.com Subject: [PATCH v3 2/5] KVM: s390: Fix unlikely race in try_get_locked_pte() Date: Thu, 11 Jun 2026 12:48:47 +0200 Message-ID: <20260611104850.110313-3-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260611104850.110313-1-imbrenda@linux.ibm.com> References: <20260611104850.110313-1-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjExMDEwNiBTYWx0ZWRfX8o3f86JFmvSJ o2YrkTbC/Bs0UaNWdz2BPd8h9oliwV8FK1Z0/EtHCwppI+TMOHT4Mgi2afEXJPqZ39cdTmO+Dhq UApRddkU7XteDNOi+GBMhQyiquPw/d/c9pQVKzroznCgqhWbhqlqiawCkcOUPpi7XI5OqtvdTnE ea+ZgTOYUy2B6QM+RSKDboD40Kk7mzLDfXMsbu7l6tjNVS4oieqTGDPDQDnh/eD0cS1DZBY2DJ3 HfHCt5ws1L+6uhACFiBiOf/09oDC+jqDh0OdR8qd/DXv+0wWaszfTMPCQcLrhDb2UWGqXeR7wVl 35fYqESyLsHFaPMzn2/0NZJ7s7BWIcH2EeH5cBYUzZktJfongMUP7QGymiM7QNc20WoZ8ML6pcr XMaWjBhIjTTITgUJ4GpeohQvOI2Feehc2kDNpid/+i7y4kIxclhK1Argh71rdtcSux5PsDAJ1sD sHkKpaFFUl2Y1y0s5Uw== X-Authority-Analysis: v=2.4 cv=dr7rzVg4 c=1 sm=1 tr=0 ts=6a2a929a cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=FelO9ux0wxsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=VnNF1IyMAAAA:8 a=VwQbUJbxAAAA:8 a=WbevkOawJw57NP_rgK0A:9 X-Proofpoint-ORIG-GUID: 0hgAf1K2y8VMPjRIhSLs7Wa2lka0Rkci X-Proofpoint-GUID: 0hgAf1K2y8VMPjRIhSLs7Wa2lka0Rkci X-Proofpoint-Spam-Info: AW1haW4tMjYwNjExMDEwNiBTYWx0ZWRfX/Ygio7RNG2sk y2ixIUc+5UcPMX++13+oIAPOeGsxd2uazCm25p0jZ924+pkcMkjDugmg1BExoXhAOOGcjguYXrC zGVhKCBgJMgb9mAoaJZLLTK0D5G+FwU= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-06-11_02,2026-06-09_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 adultscore=0 suspectscore=0 priorityscore=1501 phishscore=0 clxscore=1015 bulkscore=0 impostorscore=0 lowpriorityscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606040000 definitions=main-2606110106 Fix an unlikely race in try_get_locked_pte(), which could have happened if puds or pmds get unmapped between the p?dp_get() and p?d_offset() functions. Fixes: 89fa757931dc ("KVM: s390: Avoid potentially sleeping while atomic when zapping pages") Signed-off-by: Claudio Imbrenda CC: stable@vger.kernel.org # 7.1 --- arch/s390/mm/gmap_helpers.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/s390/mm/gmap_helpers.c b/arch/s390/mm/gmap_helpers.c index 1cfe4724fbe2..ee3f37af8aee 100644 --- a/arch/s390/mm/gmap_helpers.c +++ b/arch/s390/mm/gmap_helpers.c @@ -51,15 +51,15 @@ pte_t *try_get_locked_pte(struct mm_struct *mm, unsigned long vmaddr, spinlock_t pgd = pgdp_get(pgdp); if (pgd_none(pgd) || !pgd_present(pgd)) return NULL; - p4dp = p4d_offset(pgdp, vmaddr); + p4dp = p4d_offset_lockless(pgdp, pgd, vmaddr); p4d = p4dp_get(p4dp); if (p4d_none(p4d) || !p4d_present(p4d)) return NULL; - pudp = pud_offset(p4dp, vmaddr); + pudp = pud_offset_lockless(p4dp, p4d, vmaddr); pud = pudp_get(pudp); if (pud_none(pud) || pud_leaf(pud) || !pud_present(pud)) return NULL; - pmdp = pmd_offset(pudp, vmaddr); + pmdp = pmd_offset_lockless(pudp, pud, vmaddr); pmd = pmdp_get_lockless(pmdp); if (pmd_none(pmd) || pmd_leaf(pmd) || !pmd_present(pmd)) return NULL; -- 2.54.0