6.1-stable review patch. If anyone has any objections, please let me know.
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From: Liam R. Howlett Liam.Howlett@oracle.com
commit 51f625377561e5b167da2db5aafb7ee268f691c5 upstream.
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... Reviewed-by: Lorenzo Stoakes lstoakes@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Liam R. Howlett Liam.Howlett@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/mempolicy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1525,8 +1525,10 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, /* * Only update home node if there is an existing vma policy */ - if (!new) + if (!new) { + prev = vma; continue; + }
/* * If any vma in the range got policy other than MPOL_BIND