{"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"}}}}