+ mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch added to mm-unstable branch

+ mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mprotect: replace can_modify_mm with can_modify_vma
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Pedro Falcato <pedro.falcato@gmail.com>
Subject: mm/mprotect: replace can_modify_mm with can_modify_vma
Date: Sat, 17 Aug 2024 01:18:30 +0100

Avoid taking an extra trip down the mmap tree by checking the vmas
directly.  mprotect (per POSIX) tolerates partial failure.

Link: https://lkml.kernel.org/r/20240817-mseal-depessimize-v3-3-d8d2e037df30@gmail.com
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mprotect.c |   12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

--- a/mm/mprotect.c~mm-mprotect-replace-can_modify_mm-with-can_modify_vma
+++ a/mm/mprotect.c
@@ -611,6 +611,9 @@ mprotect_fixup(struct vma_iterator *vmi,
 	unsigned long charged = 0;
 	int error;
 
+	if (!can_modify_vma(vma))
+		return -EPERM;
+
 	if (newflags == oldflags) {
 		*pprev = vma;
 		return 0;
@@ -769,15 +772,6 @@ static int do_mprotect_pkey(unsigned lon
 		}
 	}
 
-	/*
-	 * checking if memory is sealed.
-	 * can_modify_mm assumes we have acquired the lock on MM.
-	 */
-	if (unlikely(!can_modify_mm(current->mm, start, end))) {
-		error = -EPERM;
-		goto out;
-	}
-
 	prev = vma_prev(&vmi);
 	if (start > vma->vm_start)
 		prev = vma;
_

Patches currently in -mm which might be from pedro.falcato@gmail.com are

selftests-mm-add-mseal-test-for-no-discard-madvise.patch
selftests-mm-add-mseal-test-for-no-discard-madvise-fix.patch
mm-move-can_modify_vma-to-mm-vmah.patch
mm-munmap-replace-can_modify_mm-with-can_modify_vma.patch
mm-mprotect-replace-can_modify_mm-with-can_modify_vma.patch
mm-mremap-replace-can_modify_mm-with-can_modify_vma.patch
mseal-replace-can_modify_mm_madv-with-a-vma-variant.patch
mm-remove-can_modify_mm.patch
selftests-mm-add-more-mseal-traversal-tests.patch