The quilt patch titled Subject: maple_tree: add mas_is_active() to detect in-tree walks has been removed from the -mm tree. Its filename was maple_tree-add-mas_active-to-detect-in-tree-walks.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: "Liam R. Howlett" Liam.Howlett@oracle.com Subject: maple_tree: add mas_is_active() to detect in-tree walks Date: Thu, 21 Sep 2023 14:12:35 -0400

Patch series "maple_tree: Fix mas_prev() state regression".

Pedro Falcato retported an mprotect regression [1] which was bisected back to the iterator changes for maple tree. Root cause analysis showed the mas_prev() running off the end of the VMA space (previous from 0) followed by mas_find(), would skip the first value.

This patchset introduces maple state underflow/overflow so the sequence of calls on the maple state will return what the user expects.

Users who encounter this bug may see mprotect(), userfaultfd_register(), and mlock() fail on VMAs mapped with address 0.

This patch (of 2):

Instead of constantly checking each possibility of the maple state, create a fast path that will skip over checking unlikely states.

Link: https://lkml.kernel.org/r/20230921181236.509072-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20230921181236.509072-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Liam.Howlett@oracle.com Cc: Pedro Falcato pedro.falcato@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

include/linux/maple_tree.h | 9 +++++++++ 1 file changed, 9 insertions(+)

--- a/include/linux/maple_tree.h~maple_tree-add-mas_active-to-detect-in-tree-walks +++ a/include/linux/maple_tree.h @@ -511,6 +511,15 @@ static inline bool mas_is_paused(const s return mas->node == MAS_PAUSE; }

+/* Check if the mas is pointing to a node or not */ +static inline bool mas_is_active(struct ma_state *mas) +{ + if ((unsigned long)mas->node >= MAPLE_RESERVED_RANGE) + return true; + + return false; +} + /** * mas_reset() - Reset a Maple Tree operation state. * @mas: Maple Tree operation state. _

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

maple_tree-add-mas_underflow-and-mas_overflow-states.patch mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer.patch mmap-fix-vma_iterator-in-error-path-of-vma_merge.patch mmap-fix-error-paths-with-dup_anon_vma.patch mmap-add-clarifying-comment-to-vma_merge-code.patch radix-tree-test-suite-fix-allocation-calculation-in-kmem_cache_alloc_bulk.patch