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@xxxxxxxxx>
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@xxxxxxxxx
Signed-off-by: Pedro Falcato <pedro.falcato@xxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxx 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
