The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 51f625377561e5b167da2db5aafb7ee268f691c5 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023102704-surrogate-dole-2888@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 51f625377561e5b167da2db5aafb7ee268f691c5 Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Date: Thu, 28 Sep 2023 13:24:32 -0400 Subject: [PATCH] mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer 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@xxxxxxxxxx Link: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HGJsmLcUuwQ@xxxxxxxxxxxxxx/ Fixes: f4e9e0e69468 ("mm/mempolicy: fix use-after-free of VMA iterator") Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Reported-by: Yikebaer Aizezi <yikebaer61@xxxxxxxxx> Closes: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HGJsmLcUuwQ@xxxxxxxxxxxxxx/ Reviewed-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> diff --git a/mm/mempolicy.c b/mm/mempolicy.c index f1b00d6ac7ee..29ebf1e7898c 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1543,8 +1543,10 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le * 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;
