{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53108", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.385Z", "datePublished": "2026-06-24T16:30:42.707Z", "dateUpdated": "2026-06-24T16:30:42.707Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-06-24T16:30:42.707Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Fix unmap race with PMD migration entries\n\nThe following race is possible with migration swap entries or\ndevice-private THP entries. e.g. when move_pages is called on a PMD THP\npage, then there maybe an intermediate state, where PMD entry acts as\na migration swap entry (pmd_present() is true). Then if an munmap\nhappens at the same time, then this VM_BUG_ON() can happen in\npmdp_huge_get_and_clear_full().\n\nThis patch fixes that.\n\nThread A: move_pages() syscall\n add_folio_for_migration()\n mmap_read_lock(mm)\n folio_isolate_lru(folio)\n mmap_read_unlock(mm)\n\n do_move_pages_to_node()\n migrate_pages()\n try_to_migrate_one()\n spin_lock(ptl)\n set_pmd_migration_entry()\n pmdp_invalidate() # PMD: _PAGE_INVALID | _PAGE_PTE | pfn\n set_pmd_at() # PMD: migration swap entry (pmd_present=0)\n spin_unlock(ptl)\n [page copy phase] # <--- RACE WINDOW -->\n\nThread B: munmap()\n mmap_write_downgrade(mm)\n unmap_vmas() -> zap_pmd_range()\n zap_huge_pmd()\n __pmd_trans_huge_lock()\n pmd_is_huge(): # !pmd_present && !pmd_none -> TRUE (swap entry)\n pmd_lock() -> \t\t# spin_lock(ptl), waits for Thread A to release ptl\n pmdp_huge_get_and_clear_full()\n VM_BUG_ON(!pmd_present(*pmdp)) # HITS!\n\n[ 287.738700][ T1867] ------------[ cut here ]------------\n[ 287.743843][ T1867] kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:187!\ncpu 0x0: Vector: 700 (Program Check) at [c00000044037f4f0]\n pc: c000000000094ca4: pmdp_huge_get_and_clear_full+0x6c/0x23c\n lr: c000000000645dec: zap_huge_pmd+0xb0/0x868\n sp: c00000044037f790\n msr: 800000000282b033\n current = 0xc0000004032c1a00\n paca = 0xc000000004fe0000 irqmask: 0x03 irq_happened: 0x09\n pid = 1867, comm = a.out\nkernel BUG at :187!\nLinux version 6.19.0-12136-g14360d4f917c-dirty (powerpc64le-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #27 SMP PREEMPT Sun Feb 22 10:38:56 IST 2026\nenter ? for help\n[link register ] c000000000645dec zap_huge_pmd+0xb0/0x868\n[c00000044037f790] c00000044037f7d0 (unreliable)\n[c00000044037f7d0] c000000000645dcc zap_huge_pmd+0x90/0x868\n[c00000044037f840] c0000000005724cc unmap_page_range+0x176c/0x1f40\n[c00000044037fa00] c000000000572ea0 unmap_vmas+0xb0/0x1d8\n[c00000044037fa90] c0000000005af254 unmap_region+0xb4/0x128\n[c00000044037fb50] c0000000005af400 vms_complete_munmap_vmas+0x138/0x310\n[c00000044037fbe0] c0000000005b0f1c do_vmi_align_munmap+0x1ec/0x238\n[c00000044037fd30] c0000000005b3688 __vm_munmap+0x170/0x1f8\n[c00000044037fdf0] c000000000587f74 sys_munmap+0x2c/0x40\n[c00000044037fe10] c000000000032668 system_call_exception+0x128/0x350\n[c00000044037fe50] c00000000000d05c system_call_vectored_common+0x15c/0x2ec\n---- Exception: 3000 (System Call Vectored) at 0000000010064a2c\nSP (7fff9b1ee9c0) is in userspace\n0:mon> zh\n\ncommit a30b48bf1b24 (\"mm/migrate_device: implement THP migration of zone device pages\"),\nenabled migration for device-private PMD entries. Hence this is one\nother path where this warning could get trigger from.\n\n ------------[ cut here ]------------\n WARNING: arch/powerpc/mm/book3s64/hash_pgtable.c:199 at hash__pmd_hugepage_update+0x48/0x284, CPU#3: hmm-tests/1905\n Modules linked in: test_hmm\n CPU: 3 UID: 0 PID: 1905 Comm: hmm-tests Tainted: G B W L N 7.0.0-rc1-01438-g7e2f0ee7581c #21 PREEMPT\n Tainted: [B]=BAD_PAGE, [W]=WARN, [L]=SOFTLOCKUP, [N]=TEST\n Hardware name: IBM pSeries (emulated by qemu) POWER10 (architected) 0x801200 0xf000006 of:SLOF,git-ee03ae pSeries\n NIP [c000000000096b70] hash__pmd_hugepage_update+0x48/0x284\n LR [c000000000096e7c] hash__pmdp_huge_get_and_clear+0xd0/0xd4\n Call Trace:\n [c000000604707670] [c000000004e102b8] 0xc000000004e102b8 (unreliable)\n [c000000604707700] [c00000000064ec3c] set_pmd_migration_entry+0x414/0x498\n [c000000604707760] [c00000000063e5a4] migrate_vma_col\n---truncated---" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/book3s/64/pgtable.h", "arch/powerpc/mm/book3s64/pgtable.c" ], "versions": [ { "version": "75358ea359e7c0dfceb3c7b3d854570b4260cb7f", "lessThan": "829367e55012c053738ebe7db20c4a90d6609ece", "status": "affected", "versionType": "git" }, { "version": "75358ea359e7c0dfceb3c7b3d854570b4260cb7f", "lessThan": "bbcbf045d6c778e82b47a35fc8728387708e9a3d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/book3s/64/pgtable.h", "arch/powerpc/mm/book3s64/pgtable.c" ], "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.0.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/829367e55012c053738ebe7db20c4a90d6609ece" }, { "url": "https://git.kernel.org/stable/c/bbcbf045d6c778e82b47a35fc8728387708e9a3d" } ], "title": "powerpc/64s: Fix unmap race with PMD migration entries", "x_generator": { "engine": "bippy-1.2.0" } } } }