The patch titled Subject: mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: "Liam R. Howlett" Liam.Howlett@oracle.com Subject: mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer Date: Thu, 28 Sep 2023 13:24:32 -0400

The two users of mbind_range() are expecting that mbind_range() will update the pointer to the previous VMA, or return an error. However, set_mempolicy_home_node() does not call mbind_range() if there is no VMA policy. The fix is to update the pointer to the previous VMA prior to continuing iterating the VMAs when there is no policy.

Users may experience a WARN_ON() during VMA policy updates when updating a range of VMAs on the home node.

Link: https://lkml.kernel.org/r/20230928172432.2246534-1-Liam.Howlett@oracle.com Link: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HGJ... Fixes: f4e9e0e69468 ("mm/mempolicy: fix use-after-free of VMA iterator") Signed-off-by: Liam R. Howlett Liam.Howlett@oracle.com Reported-by: Yikebaer Aizezi yikebaer61@gmail.com Closes: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HGJ... Cc: Lorenzo Stoakes lstoakes@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/mempolicy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/mempolicy.c~mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer +++ a/mm/mempolicy.c @@ -1543,8 +1543,10 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, * the home node for vmas we already updated before. */ old = vma_policy(vma); - if (!old) + if (!old) { + prev = vma; continue; + } if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) { err = -EOPNOTSUPP; break; _

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

maple_tree-add-mas_active-to-detect-in-tree-walks.patch maple_tree-add-mas_underflow-and-mas_overflow-states.patch mmap-fix-vma_iterator-in-error-path-of-vma_merge.patch mmap-fix-error-paths-with-dup_anon_vma.patch mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer.patch mmap-add-clarifying-comment-to-vma_merge-code.patch