5.10-stable patches

added patches:
	mm-khugepaged-skip-huge-page-collapse-for-special-files.patch

diff --git a/queue-5.10/mm-khugepaged-skip-huge-page-collapse-for-special-files.patch b/queue-5.10/mm-khugepaged-skip-huge-page-collapse-for-special-files.patch
new file mode 100644 (file)
index 0000000..26eb44a
--- /dev/null
+++ b/queue-5.10/mm-khugepaged-skip-huge-page-collapse-for-special-files.patch
@@ -0,0 +1,77 @@
+From a4aeaa06d45e90f9b279f0b09de84bd00006e733 Mon Sep 17 00:00:00 2001
+From: Yang Shi <shy828301@gmail.com>
+Date: Thu, 28 Oct 2021 14:36:30 -0700
+Subject: mm: khugepaged: skip huge page collapse for special files
+
+From: Yang Shi <shy828301@gmail.com>
+
+commit a4aeaa06d45e90f9b279f0b09de84bd00006e733 upstream.
+
+The read-only THP for filesystems will collapse THP for files opened
+readonly and mapped with VM_EXEC.  The intended usecase is to avoid TLB
+misses for large text segments.  But it doesn't restrict the file types
+so a THP could be collapsed for a non-regular file, for example, block
+device, if it is opened readonly and mapped with EXEC permission.  This
+may cause bugs, like [1] and [2].
+
+This is definitely not the intended usecase, so just collapse THP for
+regular files in order to close the attack surface.
+
+[shy828301@gmail.com: fix vm_file check [3]]
+
+Link: https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/ [1]
+Link: https://lore.kernel.org/linux-mm/000000000000c6a82505ce284e4c@google.com/ [2]
+Link: https://lkml.kernel.org/r/CAHbLzkqTW9U3VvTu1Ki5v_cLRC9gHW+znBukg_ycergE0JWj-A@mail.gmail.com [3]
+Link: https://lkml.kernel.org/r/20211027195221.3825-1-shy828301@gmail.com
+Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
+Signed-off-by: Hugh Dickins <hughd@google.com>
+Signed-off-by: Yang Shi <shy828301@gmail.com>
+Reported-by: Hao Sun <sunhao.th@gmail.com>
+Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com
+Cc: Matthew Wilcox <willy@infradead.org>
+Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Cc: Song Liu <songliubraving@fb.com>
+Cc: Andrea Righi <andrea.righi@canonical.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/khugepaged.c |   17 ++++++++++-------
+ 1 file changed, 10 insertions(+), 7 deletions(-)
+
+--- a/mm/khugepaged.c
++++ b/mm/khugepaged.c
+@@ -443,21 +443,24 @@ static bool hugepage_vma_check(struct vm
+       if (!transhuge_vma_enabled(vma, vm_flags))
+               return false;
+ 
++      if (vma->vm_file && !IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) -
++                              vma->vm_pgoff, HPAGE_PMD_NR))
++              return false;
++
+       /* Enabled via shmem mount options or sysfs settings. */
+-      if (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) {
+-              return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
+-                              HPAGE_PMD_NR);
+-      }
++      if (shmem_file(vma->vm_file))
++              return shmem_huge_enabled(vma);
+ 
+       /* THP settings require madvise. */
+       if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+               return false;
+ 
+-      /* Read-only file mappings need to be aligned for THP to work. */
++      /* Only regular file is valid */
+       if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file &&
+           (vm_flags & VM_DENYWRITE)) {
+-              return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
+-                              HPAGE_PMD_NR);
++              struct inode *inode = vma->vm_file->f_inode;
++
++              return S_ISREG(inode->i_mode);
+       }
+ 
+       if (!vma->anon_vma || vma->vm_ops)

diff --git a/queue-5.10/series b/queue-5.10/series
index ba4acbccb0527b5b28d6d9f5eb782e3406aa6a1b..d32e2433a8705953b963c38b6db2330ee1679c65 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -8,3 +8,4 @@ mm-filemap-check-if-thp-has-hwpoisoned-subpage-for-pmd-page-fault.patch
 media-firewire-firedtv-avc-fix-a-buffer-overflow-in-avc_ca_pmt.patch
 revert-xhci-set-hcd-flag-to-defer-primary-roothub-registration.patch
 revert-usb-core-hcd-add-support-for-deferring-roothub.patch
+mm-khugepaged-skip-huge-page-collapse-for-special-files.patch