OpenCloudOS-Kernel/mm
David Hildenbrand 51b7841f3f x86/mm/pat: fix VM_PAT handling in COW mappings
commit 04c35ab3bdae7fefbd7c7a7355f29fa03a035221 upstream.

PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios.  Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.

Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().

In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.

To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.

We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode.  We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.

For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.

Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():

<--- C reproducer --->
 #include <stdio.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <liburing.h>

 int main(void)
 {
         struct io_uring_params p = {};
         int ring_fd;
         size_t size;
         char *map;

         ring_fd = io_uring_setup(1, &p);
         if (ring_fd < 0) {
                 perror("io_uring_setup");
                 return 1;
         }
         size = p.sq_off.array + p.sq_entries * sizeof(unsigned);

         /* Map the submission queue ring MAP_PRIVATE */
         map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
                    ring_fd, IORING_OFF_SQ_RING);
         if (map == MAP_FAILED) {
                 perror("mmap");
                 return 1;
         }

         /* We have at least one page. Let's COW it. */
         *map = 0;
         pause();
         return 0;
 }
<--- C reproducer --->

On a system with 16 GiB RAM and swap configured:
 # ./iouring &
 # memhog 16G
 # killall iouring
[  301.552930] ------------[ cut here ]------------
[  301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[  301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[  301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[  301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[  301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[  301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[  301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[  301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[  301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[  301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[  301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[  301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[  301.564186] FS:  0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[  301.564773] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[  301.565725] PKRU: 55555554
[  301.565944] Call Trace:
[  301.566148]  <TASK>
[  301.566325]  ? untrack_pfn+0xf4/0x100
[  301.566618]  ? __warn+0x81/0x130
[  301.566876]  ? untrack_pfn+0xf4/0x100
[  301.567163]  ? report_bug+0x171/0x1a0
[  301.567466]  ? handle_bug+0x3c/0x80
[  301.567743]  ? exc_invalid_op+0x17/0x70
[  301.568038]  ? asm_exc_invalid_op+0x1a/0x20
[  301.568363]  ? untrack_pfn+0xf4/0x100
[  301.568660]  ? untrack_pfn+0x65/0x100
[  301.568947]  unmap_single_vma+0xa6/0xe0
[  301.569247]  unmap_vmas+0xb5/0x190
[  301.569532]  exit_mmap+0xec/0x340
[  301.569801]  __mmput+0x3e/0x130
[  301.570051]  do_exit+0x305/0xaf0
...

Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes: b1a86e15dc ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
Fixes: 5899329b19 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:36:03 +02:00
..
damon mm/damon/reclaim: fix quota stauts loss due to online tunings 2024-03-01 13:35:00 +01:00
kasan kasan/test: avoid gcc warning for intentional overflow 2024-04-03 15:28:20 +02:00
kfence LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
kmsan mm: kmsan: use helper macros PAGE_ALIGN and PAGE_ALIGN_DOWN 2023-08-21 13:37:29 -07:00
Kconfig - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
Kconfig.debug mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM 2023-05-29 16:14:28 +01:00
Makefile - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
backing-dev.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:25:16 +01:00
balloon_compaction.c
bootmem_info.c
cma.c mm/cma: use nth_page() in place of direct struct page manipulation 2023-11-28 17:20:06 +00:00
cma.h
cma_debug.c
cma_sysfs.c mm: cma: make kobj_type structure constant 2023-03-28 16:20:06 -07:00
compaction.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:28:44 +02:00
debug.c mm: update validate_mm() to use vma iterator 2023-06-09 16:25:31 -07:00
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 14:48:41 +00:00
dmapool.c dmapool: create/destroy cleanup 2023-06-09 16:25:17 -07:00
dmapool_test.c dmapool: add alloc/free performance test 2023-04-05 19:42:38 -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 mm: fix unexpected changes to {failslab|fail_page_alloc}.attr 2022-11-22 18:50:44 -08:00
filemap.c mm: cachestat: fix two shmem bugs 2024-04-03 15:28:55 +02:00
folio-compat.c filemap: Add fgf_t typedef 2023-07-24 18:04:30 -04:00
gup.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
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 mm/gup_test: start/stop/read functionality for PIN LONGTERM test 2022-11-08 17:37:15 -08:00
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: fix for negative counter: nr_file_hugepages 2023-11-28 17:20:13 +00:00
hugetlb.c hugetlb: fix null-ptr-deref in hugetlb_vma_lock_write 2023-12-13 18:45:24 +01:00
hugetlb_cgroup.c mm/hugetlb: increase use of folios in alloc_huge_page() 2023-02-13 15:54:27 -08:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: fix a race between vmemmap pmd split 2023-08-18 10:12:14 -07:00
hugetlb_vmemmap.h
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 Add x86 shadow stack support 2023-08-31 12:20:12 -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
khugepaged.c - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
kmemleak.c mm/kmemleak: move up cond_resched() call in page scanning loop 2023-09-02 15:17:34 -07:00
ksm.c mm: memory-failure: use rcu lock instead of tasklist_lock when collect_procs() 2023-09-05 11:11:52 -07:00
list_lru.c
maccess.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
madvise.c swap: remove remnants of polling from read_swap_cache_async 2023-08-24 16:20:16 -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 13:35:06 +01:00
memcontrol.c mm: memcontrol: clarify swapaccount=0 deprecation warning 2024-03-01 13:35:00 +01:00
memfd.c revert "memfd: improve userspace warnings for missing exec-related flags". 2023-09-05 11:11:52 -07:00
memory-failure.c mm/memory-failure: pass the folio and the page to collect_procs() 2024-01-10 17:16:54 +01:00
memory-tiers.c memory tier: use helper macro __ATTR_RW() 2023-08-18 10:12:38 -07:00
memory.c x86/mm/pat: fix VM_PAT handling in COW mappings 2024-04-10 16:36:03 +02:00
memory_hotplug.c mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval 2024-01-20 11:51:49 +01:00
mempolicy.c numa: Generalize numa_map_to_online_node() 2023-11-20 11:58:51 +01:00
mempool.c mempool: do not use ksize() for poisoning 2022-11-30 15:58:41 -08:00
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 15:28:33 +02:00
migrate.c mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index 2024-03-15 10:48:14 -04:00
migrate_device.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
mm_init.c efi: disable mirror feature during crashkernel 2024-01-31 16:18:56 -08:00
mm_slot.h
mmap.c mm, mmap: fix vma_merge() case 7 with vma_ops->close 2024-04-03 15:28:40 +02:00
mmap_lock.c
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
mprotect.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
mremap.c vm: fix move_vma() memory accounting being off 2023-09-16 15:23:31 -07:00
msync.c
nommu.c Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
oom_kill.c mm: remove redundant K() macro definition 2023-08-21 13:37:44 -07:00
page-writeback.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:25:16 +01:00
page_alloc.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:28:44 +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 zswap: make zswap_load() take a folio 2023-08-21 13:37:27 -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_ext: use page_ext_data helper in page_owner 2023-08-21 13:37:27 -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
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 19:10:52 +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 10:48:21 -04:00
rmap.c mm: hugetlb: add huge page size param to set_huge_pte_at() 2023-09-29 17:20:47 -07:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem.c quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-04-03 15:28:54 +02:00
show_mem.c mm,thp: no space after colon in Mem-Info fields 2023-08-21 13:38:01 -07:00
shrinker_debug.c Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" 2023-06-19 13:19:34 -07:00
shuffle.c mm/shuffle: convert module_param_call to module_param_cb 2022-10-03 14:03:07 -07:00
shuffle.h mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
slab.c Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab.h Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab_common.c mm: slab: Do not create kmalloc caches smaller than arch_slab_minalign() 2023-10-11 15:24:49 +02:00
slub.c mm/slub: remove freelist_dereference() 2023-07-14 09:57:21 +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 16:18:56 -08:00
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 13:35:00 +01:00
swap_cgroup.c mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled 2022-10-03 14:03:36 -07:00
swap_slots.c
swap_state.c mm/swap: inline folio_set_swap_entry() and folio_swap_entry() 2023-08-24 16:20:28 -07:00
swapfile.c mm: swap: fix race between free_swap_and_cache() and swapoff() 2024-04-03 15:28:27 +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 09:24:53 +01:00
util.c parisc: fix mmap_base calculation when stack grows upwards 2023-11-28 17:20:08 +00:00
vmalloc.c mm: hugetlb: add huge page size param to set_huge_pte_at() 2023-09-29 17:20:47 -07:00
vmpressure.c net-memcg: Fix scope of sockmem pressure indicators 2023-08-16 12:21:32 +01:00
vmscan.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-03 15:28:44 +02:00
vmstat.c mm/vmstat: remove unused page_ext.h from vmstat 2023-08-21 13:37:30 -07:00
workingset.c mm/mglru: fix underprotected page cache 2023-12-20 17:02:02 +01:00
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 merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
zswap.c mm: zswap: fix missing folio cleanup in writeback race path 2024-03-01 13:35:10 +01:00