From 64ae7959a1df8af8eec504e31df2ec9670424a4e Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Sat, 31 Oct 2026 10:39:56 +0100 Subject: [PATCH] mm/mmu_gather: fix flushing ranges with 4 GiB or larger __tlb_adjust_range() takes the size of the range which has to be flushed as an unsigned int. Its callers, tlb_flush_{pte,pmd,pud,p4d}_range(), get and pass an unsigned long. Consequently, a range that is 4 GiB or larger gets truncated, possibly to 0. On arm64 with hugetlb, a 64k kernel can have 16 GiB hugetlb folios mapped contiguously at the PMD level and flush them when unmapping, and a 16k kernel can flush 64 GiB PUDs through tlb_unshare_pmd_ptdesc(). So at least these two scenarios are affected. Fix it by flushing the proper range instead of the truncated one by properly using "unsigned long" for range_size. Fix generated by an LLM and sent by Josef Bacik in private. Fixes: b528e4b6405b ("mm/hugetlb: add tlb_remove_hugetlb_entry for handling hugetlb pages") Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather") Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik Acked-by: Lorenzo Stoakes (ARM) [ david: use two-tab indent, simplify description ] Reviewed-by: Qi Zheng Reviewed-by: Gregory Price (Meta) Tested-by: Gregory Price (Meta) Reviewed-by: Dev Jain Reviewed-by: Muchun Song Reviewed-by: Pedro Falcato Reviewed-by: SJ Park Tested-by: Muhammad Usama Anjum Link: https://patch.msgid.link/20261031-fixes_core-v3-27-d6437171ecc3@kernel.org Signed-off-by: David Hildenbrand (Arm) --- include/asm-generic/tlb.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index fbe1114e9a44..3f4a180b48f3 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -350,8 +350,7 @@ struct mmu_gather { void tlb_flush_mmu(struct mmu_gather *tlb); static inline void __tlb_adjust_range(struct mmu_gather *tlb, - unsigned long address, - unsigned int range_size) + unsigned long address, unsigned long range_size) { tlb->start = min(tlb->start, address); tlb->end = max(tlb->end, address + range_size);