linux/mm
Johannes Weiner d962f6c583 mm: cachestat: fix two shmem bugs
commit d5d39c707a upstream.

When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:

1) A swapin error can have resulted in a poisoned swap entry in the
   shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
   will result in an out-of-bounds access to swapper_spaces[].

   Validate the entry with non_swap_entry() before going further.

2) When we find a valid swap entry in the shmem's inode, the shadow
   entry in the swapcache might not exist yet: swap IO is still in
   progress and we're before __remove_mapping; swapin, invalidation,
   or swapoff have removed the shadow from swapcache after we saw the
   shmem swap entry.

   This will send a NULL to workingset_test_recent(). The latter
   purely operates on pointer bits, so it won't crash - node 0, memcg
   ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
   bogus test. In theory that could result in a false "recently
   evicted" count.

   Such a false positive wouldn't be the end of the world. But for
   code clarity and (future) robustness, be explicit about this case.

   Bail on get_shadow_from_swap_cache() returning NULL.

Link: https://lkml.kernel.org/r/20240315095556.GC581298@cmpxchg.org
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Chengming Zhou <chengming.zhou@linux.dev>	[Bug #1]
Reported-by: Jann Horn <jannh@google.com>		[Bug #2]
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>				[v6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-03 15:11:49 +02:00
..
damon mm/damon/reclaim: fix quota stauts loss due to online tunings 2024-03-01 13:41:47 +01:00
kasan kasan/test: avoid gcc warning for intentional overflow 2024-04-03 15:11:11 +02:00
kfence LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
kmsan mm: kmsan: panic on failure to allocate early boot metadata 2023-10-25 16:47:10 -07:00
backing-dev.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:51:56 +01:00
balloon_compaction.c
bootmem_info.c bootmem: use kmemleak_free_part_phys in put_page_bootmem 2023-10-25 16:47:13 -07:00
cma_debug.c
cma_sysfs.c mm: cma: make kobj_type structure constant 2023-03-28 16:20:06 -07:00
cma.c mm/cma: use nth_page() in place of direct struct page manipulation 2023-10-04 10:32:29 -07:00
cma.h
compaction.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:11:40 +02:00
debug_page_alloc.c mm: page_alloc: split out DEBUG_PAGEALLOC 2023-06-09 16:25:23 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: fix BUG_ON with pud advanced test 2024-03-06 14:53:57 +00:00
debug.c mm: update validate_mm() to use vma iterator 2023-06-09 16:25:31 -07:00
dmapool_test.c dmapool: add alloc/free performance test 2023-04-05 19:42:38 -07:00
dmapool.c dmapool: create/destroy cleanup 2023-06-09 16:25:17 -07:00
early_ioremap.c mm/early_ioremap.c: improve the execution efficiency of early_ioremap_setup() 2023-06-09 16:25:56 -07:00
fadvise.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
fail_page_alloc.c mm: page_alloc: split out FAIL_PAGE_ALLOC 2023-06-09 16:25:23 -07:00
failslab.c
filemap.c mm: cachestat: fix two shmem bugs 2024-04-03 15:11:49 +02:00
folio-compat.c filemap: Add fgf_t typedef 2023-07-24 18:04:30 -04:00
gup_test.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
gup_test.h
gup.c mm/gup: make failure to pin an error if FOLL_NOWAIT not specified 2023-10-18 14:34:15 -07:00
highmem.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
hmm.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
huge_memory.c mm: thp_get_unmapped_area must honour topdown preference 2024-02-23 09:51:28 +01:00
hugetlb_cgroup.c mm, hugetlb: remove HUGETLB_CGROUP_MIN_ORDER 2023-10-18 14:34:17 -07:00
hugetlb_vmemmap.c hugetlb_vmemmap: use folio argument for hugetlb_vmemmap_* functions 2023-10-25 16:47:08 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: fix reference to nonexistent file 2023-10-25 16:47:14 -07:00
hugetlb.c hugetlb: fix null-ptr-deref in hugetlb_vma_lock_write 2023-12-06 16:12:43 -08:00
hwpoison-inject.c
init-mm.c mm: move dummy_vm_ops out of a header 2023-08-21 13:37:46 -07:00
internal.h mm: add page_rmappable_folio() wrapper 2023-10-25 16:47:16 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
Kconfig mm/Kconfig: make userfaultfd a menuconfig 2023-12-06 16:12:47 -08:00
Kconfig.debug mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM 2023-05-29 16:14:28 +01:00
khugepaged.c As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
kmemleak.c mm/kmemleak: move set_track_prepare() outside raw_spinlocks 2023-12-06 16:12:44 -08:00
ksm.c mm: more ptep_get() conversion 2023-11-15 15:30:09 -08:00
list_lru.c
maccess.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
madvise.c mm/madvise: add cond_resched() in madvise_cold_or_pageout_pte_range() 2023-12-06 16:12:50 -08:00
Makefile mm: vmscan: move shrinker-related code into a separate file 2023-10-04 10:32:23 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c x86/numa: Fix the address overlap check in numa_fill_memblks() 2024-03-01 13:41:54 +01:00
memcontrol.c eventfd: simplify eventfd_signal() 2024-04-03 15:11:23 +02:00
memfd.c memfd: drop warning for missing exec-related flags 2023-10-04 10:32:22 -07:00
memory_hotplug.c mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval 2024-01-20 11:53:02 +01:00
memory-failure.c fs/hugetlbfs/inode.c: mm/memory-failure.c: fix hugetlbfs hwpoison handling 2024-02-23 09:51:29 +01:00
memory-tiers.c dax, kmem: calculate abstract distance with general interface 2023-10-16 15:44:39 -07:00
memory.c mm/swap: fix race when skipping swapcache 2024-03-01 13:41:47 +01:00
mempolicy.c Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
mempool.c
memremap.c mm/memremap.c: fix outdated comment in devm_memremap_pages 2023-02-09 16:51:46 -08:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-04-03 15:11:26 +02:00
migrate_device.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
migrate.c mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index 2024-03-06 14:53:57 +00:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c mm: mlock: avoid folio_within_range() on KSM pages 2023-10-25 16:47:14 -07:00
mm_init.c efi: disable mirror feature during crashkernel 2024-01-31 16:21:02 -08:00
mm_slot.h
mmap_lock.c
mmap.c mm, mmap: fix vma_merge() case 7 with vma_ops->close 2024-04-03 15:11:36 +02:00
mmu_gather.c mm: fix kernel-doc warning from tlb_flush_rmaps() 2023-08-24 16:20:30 -07:00
mmu_notifier.c mmu_notifiers: rename invalidate_range notifier 2023-08-18 10:12:41 -07:00
mmzone.c mm: remove page_cpupid_xchg_last() 2023-10-25 16:47:13 -07:00
mprotect.c mm: mprotect: use a folio in change_pte_range() 2023-10-25 16:47:12 -07:00
mremap.c mm: abstract VMA merge and extend into vma_merge_extend() helper 2023-10-18 14:34:18 -07:00
msync.c
nommu.c Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
oom_kill.c mm/oom_killer: simplify OOM killer info dump helper 2023-10-25 16:47:10 -07:00
page_alloc.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:11:40 +02:00
page_counter.c
page_ext.c mm/page_ext: move functions around for minor cleanups to page_ext 2023-08-18 10:12:31 -07:00
page_idle.c mm: page_idle: convert page idle to use a folio 2023-01-18 17:12:52 -08:00
page_io.c mm: memcg: add THP swap out info for anonymous reclaim 2023-10-04 10:32:27 -07:00
page_isolation.c mm/hugetlb: get rid of page_hstate() 2023-08-18 10:12:39 -07:00
page_owner.c mm/page_owner: remove free_ts from page_owner output 2023-10-18 14:34:19 -07:00
page_poison.c mm/page_poison: remove unused page_ext.h from page_poison 2023-08-21 13:37:30 -07:00
page_reporting.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_reporting.h
page_table_check.c mm: convert page_table_check_pte_set() to page_table_check_ptes_set() 2023-08-24 16:20:18 -07:00
page_vma_mapped.c mm: correct stale comment of function check_pte 2023-08-18 10:12:13 -07:00
page-writeback.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:51:56 +01:00
pagewalk.c mm/pagewalk: fix bootstopping regression from extra pte_unmap() 2023-09-02 08:39:21 -07:00
percpu-internal.h percpu-internal/pcpu_chunk: re-layout pcpu_chunk structure to reduce false sharing 2023-06-19 16:19:29 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c mm: Introduce flush_cache_vmap_early() 2024-02-16 19:14:25 +01:00
pgalloc-track.h
pgtable-generic.c mm/pgtable: notes on pte_offset_map[_lock]() 2023-08-18 10:12:25 -07:00
process_vm_access.c mm/gup: remove unused vmas parameter from pin_user_pages_remote() 2023-06-09 16:25:25 -07:00
ptdump.c mm: ptdump should use ptep_get_lockless() 2023-06-19 16:19:24 -07:00
readahead.c readahead: avoid multiple marked readahead pages 2024-03-15 10:48:22 -04:00
rmap.c mm/rmap: convert page_move_anon_rmap() to folio_move_anon_rmap() 2023-10-18 14:34:14 -07:00
rodata_test.c
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-04-03 15:11:48 +02:00
shmem.c quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:18:32 -04:00
show_mem.c mm: refactor si_mem_available() 2023-10-04 10:32:19 -07:00
shrinker_debug.c mm: shrinker: convert shrinker_rwsem to mutex 2023-10-04 10:32:26 -07:00
shrinker.c mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info() 2024-01-05 09:58:32 -08:00
shuffle.c
shuffle.h mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
slab_common.c RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
slab.c Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab.h mm: kmem: scoped objcg protection 2023-10-25 16:47:11 -07:00
slub.c mm/slub: refactor calculate_order() and calc_slab_order() 2023-10-02 11:55:47 +02:00
sparse-vmemmap.c mm/vmemmap: allow architectures to override how vmemmap optimization works 2023-08-18 10:12:53 -07:00
sparse.c mm/sparsemem: fix race in accessing memory_section->usage 2024-01-31 16:21:03 -08:00
swap_cgroup.c
swap_slots.c
swap_state.c mempolicy: alloc_pages_mpol() for NUMA policy without vma 2023-10-25 16:47:16 -07:00
swap.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
swap.h mm/swap: fix race when skipping swapcache 2024-03-01 13:41:47 +01:00
swapfile.c mm: swap: fix race between free_swap_and_cache() and swapoff() 2024-04-03 15:11:19 +02:00
truncate.c - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
userfaultfd.c userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb 2024-02-23 09:51:28 +01:00
util.c parisc: fix mmap_base calculation when stack grows upwards 2023-11-15 15:30:09 -08:00
vmalloc.c mm/vmalloc: fix the unchecked dereference warning in vread_iter() 2023-11-01 12:38:35 -07:00
vmpressure.c eventfd: simplify eventfd_signal() 2024-04-03 15:11:23 +02:00
vmscan.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:11:40 +02:00
vmstat.c mm: tune PCP high automatically 2023-10-25 16:47:10 -07:00
workingset.c mm/mglru: fix underprotected page cache 2023-12-12 17:20:19 -08:00
z3fold.c mm/z3fold: remove obsolete comment for struct z3fold_pool 2023-08-21 13:37:51 -07:00
zbud.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zpool.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zsmalloc.c zsmalloc: use copy_page for full page copy 2023-10-18 14:34:16 -07:00
zswap.c mm/zswap: invalidate duplicate entry when !zswap_enabled 2024-03-01 13:42:00 +01:00