On 21/09/2023 17:30, Andrew Morton wrote: > On Thu, 21 Sep 2023 17:19:59 +0100 Ryan Roberts <ryan.roberts@xxxxxxx> wrote: > >> Hi All, >> >> This series fixes a bug in arm64's implementation of set_huge_pte_at(), which >> can result in an unprivileged user causing a kernel panic. The problem was >> triggered when running the new uffd poison mm selftest for HUGETLB memory. This >> test (and the uffd poison feature) was merged for v6.6-rc1. However, upon >> inspection there are multiple other pre-existing paths that can trigger this >> bug. >> >> Ideally, I'd like to get this fix in for v6.6 if possible? And I guess it should >> be backported too, given there are call sites where this can theoretically >> happen that pre-date v6.6-rc1 (I've cc'ed stable@xxxxxxxxxxxxxxx). > > This gets you a naggygram from Greg. The way to request a backport is > to add cc:stable to all the changelogs. I'll make that change to my copy. Ahh, sorry about that... I just got the same moan from the kernel test robot too. > > >> Ryan Roberts (8): >> parisc: hugetlb: Convert set_huge_pte_at() to take vma >> powerpc: hugetlb: Convert set_huge_pte_at() to take vma >> riscv: hugetlb: Convert set_huge_pte_at() to take vma >> s390: hugetlb: Convert set_huge_pte_at() to take vma >> sparc: hugetlb: Convert set_huge_pte_at() to take vma >> mm: hugetlb: Convert set_huge_pte_at() to take vma >> arm64: hugetlb: Convert set_huge_pte_at() to take vma >> arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries >> >> arch/arm64/include/asm/hugetlb.h | 2 +- >> arch/arm64/mm/hugetlbpage.c | 22 ++++---------- >> arch/parisc/include/asm/hugetlb.h | 2 +- >> arch/parisc/mm/hugetlbpage.c | 4 +-- >> .../include/asm/nohash/32/hugetlb-8xx.h | 3 +- >> arch/powerpc/mm/book3s64/hugetlbpage.c | 2 +- >> arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 2 +- >> arch/powerpc/mm/nohash/8xx.c | 2 +- >> arch/powerpc/mm/pgtable.c | 7 ++++- >> arch/riscv/include/asm/hugetlb.h | 2 +- >> arch/riscv/mm/hugetlbpage.c | 3 +- >> arch/s390/include/asm/hugetlb.h | 8 +++-- >> arch/s390/mm/hugetlbpage.c | 8 ++++- >> arch/sparc/include/asm/hugetlb.h | 8 +++-- >> arch/sparc/mm/hugetlbpage.c | 8 ++++- >> include/asm-generic/hugetlb.h | 6 ++-- >> include/linux/hugetlb.h | 6 ++-- >> mm/damon/vaddr.c | 2 +- >> mm/hugetlb.c | 30 +++++++++---------- >> mm/migrate.c | 2 +- >> mm/rmap.c | 10 +++---- >> mm/vmalloc.c | 5 +++- >> 22 files changed, 80 insertions(+), 64 deletions(-) > > Looks scary but it's actually a fairly modest patchset. It could > easily be all rolled into a single patch for ease of backporting. > Maybe Greg has an opinion? Yes, I thought about doing that; or perhaps 2 patches - one for the interface change across all arches and core code, and one for the actual bug fix? But I thought the arch people might prefer to see exactly what's going on in each arch. Let me know the preference and I can repost if necessary. >