kernel/linux.git/mm, branch v7.1-rc6

Merge tag 'fixes-2026-05-30' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2026-05-30T22:37:05+00:00

Pull memblock fix from Mike Rapoport: "Fix regression from memblock_free_late() refactoring After refactoring of memblock_free_late() and free_init_pages() it became possible to call memblock_free() after memblock init data was discarded. Make sure memblock_free() does not touch memblock.reserved unless it is called early enough or when ARCH_KEEP_MEMBLOCK is enabled" * tag 'fixes-2026-05-30' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock: don't touch memblock arrays when memblock_free() is called late

Merge tag 'mm-hotfixes-stable-2026-05-25-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-05-26T15:23:19+00:00

Pull misc fixes from Andrew Morton: "13 hotfixes. 9 are for MM. 9 are cc:stable and the remaining 4 address post-7.1 issues or aren't considered suitable for backporting. All patches are singletons - please see the individual changelogs for details" * tag 'mm-hotfixes-stable-2026-05-25-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: Revert "mm: introduce a new page type for page pool in page type" mm/vmalloc: do not trigger BUG() on BH disabled context MAINTAINERS, mailmap: change email for Eugen Hristev mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page kernel/fork: validate exit_signal in kernel_clone() mm: memcontrol: propagate NMI slab stats to memcg vmstats mm/damon/sysfs-schemes: delete tried region in regions_rmdirs() mm/rmap: initialize nr_pages to 1 at loop start in try_to_unmap_one zram: fix use-after-free in zram_writeback_endio memfd: deny writeable mappings when implying SEAL_WRITE ipc: limit next_id allocation to the valid ID range Revert "mm/hugetlbfs: update hugetlbfs to use mmap_prepare" MAINTAINERS: .mailmap: update after GEHC spin-off

memblock: don't touch memblock arrays when memblock_free() is called late

2026-05-25T17:48:14+00:00

When memblock_free() is called after memblock_discard() on architectures that don't select ARCH_KEEP_MEMBLOCK, it tries to update memblock.reserved that was already discarded and it causes use-after-free, for example [ 8.514775] BUG: KASAN: use-after-free in memblock_isolate_range+0x4ac/0x650 [ 8.514775] Read of size 8 at addr ffff88a07fe6a000 by task swapper/0/1 [ 8.514775] Call Trace: [ 8.514775] [ 8.514775] kasan_report+0xb2/0x1b0 [ 8.514775] memblock_isolate_range+0x4ac/0x650 [ 8.514775] memblock_phys_free+0xc4/0x190 [ 8.514775] housekeeping_late_init+0x257/0x280 [ 8.514775] do_one_initcall+0xaa/0x470 [ 8.514775] do_initcalls+0x1b4/0x1f0 [ 8.514775] kernel_init_freeable+0x4b5/0x550 [ 8.514775] kernel_init+0x1c/0x150 [ 8.514775] ret_from_fork+0x5dc/0x8e0 [ 8.514775] ret_from_fork_asm+0x1a/0x30 [ 8.514775] Make sure memblock_free() updates memblock.reserved only when called early enough or when ARCH_KEEP_MEMBLOCK is enabled. Reported-by: Waiman Long Reported-by: Breno Leitao Closes: https://lore.kernel.org/all/20260505051821.1107133-1-longman@redhat.com Tested-by: Waiman Long Tested-by: Breno Leitao Fixes: 87ce9e83ab8b ("memblock, treewide: make memblock_free() handle late freeing") Link: https://patch.msgid.link/20260513105122.502506-1-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft)

Merge tag 'cgroup-for-7.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2026-05-22T23:28:47+00:00

Pull cgroup fixes from Tejun Heo: "Two rstat fixes: - Out-of-bounds access in the css_rstat_updated() BPF kfunc when called with an unchecked user-supplied cpu - Over-strict NMI guard after the recent switch to try_cmpxchg left sparc and ppc64 unable to queue rstat updates from NMI" * tag 'cgroup-for-7.1-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: rstat: relax NMI guard after switch to try_cmpxchg cgroup/rstat: validate cpu before css_rstat_cpu() access

Merge tag 'slab-for-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2026-05-22T13:23:56+00:00

Pull slab fix from Vlastimil Babka: - Stable fix for a missing cpus_read_lock in one of the cpu sheaves flushing paths (Qing Wang) * tag 'slab-for-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slub: hold cpus_read_lock around flush_rcu_sheaves_on_cache()

Revert "mm: introduce a new page type for page pool in page type"

2026-05-22T02:06:13+00:00

This reverts commit db359fccf212 ("mm: introduce a new page type for page pool in page type") and a part of 735a309b4bfb9e ("net: add net_iov_init() and use it to initialize ->page_type"). Netpp page_type'ed pages might be used in mapping so as to use @_mapcount. However, since @page_type and @_mapcount are union'ed in struct page, these two can't be used at the same time. Revert the commit introducing page_type for Netpp for now. The patch will be retried once @page_type and @_mapcount get allowed to be used at the same time. The revert also includes removal of @page_type initialization part introduced by commit 735a309b4bfb9e ("net: add net_iov_init() and use it to initialize ->page_type"), which will be restored on the retry. Link: https://lore.kernel.org/20260515034701.17027-1-byungchul@sk.com Fixes: db359fccf212 ("mm: introduce a new page type for page pool in page type") Signed-off-by: Byungchul Park Reported-by: Dragos Tatulea Closes: https://lore.kernel.org/all/982b9bc1-0a0a-4fc5-8e3a-3672db2b29a1@nvidia.com Acked-by: Jakub Kicinski Acked-by: David Hildenbrand (Arm) Acked-by: Harry Yoo (Oracle) Reviewed-by: Lorenzo Stoakes Cc: Alexei Starovoitov Cc: Baolin Wang Cc: Brendan Jackman Cc: David S. Miller Cc: Eric Dumazet Cc: Ilias Apalodimas Cc: Jesper Dangaard Brouer Cc: Johannes Weiner Cc: John Fastabend Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Mark Bloch Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Paolo Abeni Cc: Pavel Begunkov Cc: Saeed Mahameed Cc: Simon Horman Cc: Stanislav Fomichev Cc: Suren Baghdasaryan Cc: Tariq Toukan Cc: Toke Hoiland-Jorgensen Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton

mm/vmalloc: do not trigger BUG() on BH disabled context

2026-05-22T02:06:13+00:00

__get_vm_area_node() currently triggers a BUG() if in_interrupt() returns true. However, in_interrupt() also reports true when BH are disabled. The bridge code can call rhashtable_lookup_insert_fast() with bottom halves disabled: __vlan_add() -> br_fdb_add_local() spin_lock_bh(&br->hash_lock); <-- Disable BH -> fdb_add_local() -> fdb_create() -> rhashtable_lookup_insert_fast() -> kvmalloc() -> vmalloc() -> __get_vm_area_node() -> BUG_ON(in_interrupt()) spin_unlock_bh(&br->hash_lock) this triggers the BUG() despite the caller not being in NMI or hard IRQ context. Replace the in_interrupt() check with in_nmi() || in_hardirq(). Link: https://lore.kernel.org/20260515153009.2296191-1-urezki@gmail.com Fixes: c6307674ed82 ("mm: kvmalloc: add non-blocking support for vmalloc") Signed-off-by: Uladzislau Rezki (Sony) Cc: Ido Schimmel Reported-by: syzbot+8b12fc6e0fb139765b58@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69ff8c7c.050a0220.1036b8.000b.GAE@google.com/ Reviewed-by: Baoquan He Cc: Signed-off-by: Andrew Morton

mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page

2026-05-22T02:06:13+00:00

When migrate_vma_insert_huge_pmd_page() jumps to unlock_abort due to a PMD check failure, the pgtable allocated earlier via pte_alloc_one() is never freed, causing a memory leak. Added free_abort label to release the pgtable in error path. Link: https://lore.kernel.org/20260501115122.23288-1-nueralspacetech@gmail.com Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages") Signed-off-by: Sunny Patel Acked-by: David Hildenbrand (Arm) Reviewed-by: Huang Ying Cc: Alistair Popple Cc: Balbir Singh Cc: Byungchul Park Cc: Gregory Price Cc: Joshua Hahn Cc: Matthew Brost Cc: Rakie Kim Cc: Zi Yan Cc: Signed-off-by: Andrew Morton

mm: memcontrol: propagate NMI slab stats to memcg vmstats

2026-05-22T02:06:12+00:00

flush_nmi_stats() drains per-node NMI slab atomics into the per-node lruvec_stats, but does not propagate them to the memcg-level vmstats. For non NMI case, account_slab_nmi_safe() calls mod_memcg_lruvec_state() which updates both per-node lruvec_stats and memcg-level vmstats, so flush_nmi_stats() needs to flush to per-node lruvec_stats as well as memcg-level vmstats. So fix this by flushing to the memcg-level vmstats for NMI too. Link: https://lore.kernel.org/20260518082830.599102-1-alex@ghiti.fr Fixes: 940b01fc8dc1 ("memcg: nmi safe memcg stats for specific archs") Signed-off-by: Alexandre Ghiti Acked-by: Shakeel Butt Acked-by: Johannes Weiner Reviewed-by: Harry Yoo (Oracle) Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Cc: Signed-off-by: Andrew Morton

mm/damon/sysfs-schemes: delete tried region in regions_rmdirs()

2026-05-22T02:06:12+00:00

DAMON sysfs maintains the DAMOS tried region directory objects via a linked list. When the user requests refresh of the directories, DAMON sysfs removes all the region directories first, and then generate updated regions directory on the empty space. The removal function (damon_sysfs_scheme_regions_rm_dirs()) only puts the kobj objects. Deletion of the container region object from the linked list is done inside the kobj release callback function. If somehow the callback invocation is delayed, the list will contain regions list that gonna be freed. If the updated region directories creation is started in this situation, the list can be corrupted and use-after-free can happen. Because the kobj objects are managed by only DAMON sysfs, the issue cannot happen in normal situation. But, such delays can be made on kernels that built with CONFIG_DEBUG_KOBJECT_RELEASE. On the kernel, the issue can indeed be reproduced like below. # damo start --damos_action stat # cd /sys/kernel/mm/damon/admin/kdamonds/0/ # for i in {1..10}; do echo update_schemes_tried_regions > state; done # dmesg | grep underflow [ 89.296152] refcount_t: underflow; use-after-free. Fix the issue by removing the region object from the list when decrementing the reference count. Also update damos_sysfs_populate_region_dir() to add the region object to the list only after the kobject_init_and_add() is success, so that fail of kobject_init_and_add() is not leaving the deallocated object on the list. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20260518152559.93038-1-sj@kernel.org Link: https://lore.kernel.org/20260513011920.119183-1-sj@kernel.org [1] Fixes: 9277d0367ba1 ("mm/damon/sysfs-schemes: implement scheme region directory") Signed-off-by: SeongJae Park Cc: # 6.2.x Signed-off-by: Andrew Morton