* + mm-refactor-map_deny_write_exec.patch added to mm-hotfixes-unstable branch
@ 2024-10-23 22:44 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2024-10-23 22:44 UTC (permalink / raw)
To: mm-commits, vbabka, torvalds, stable, Liam.Howlett, jannh,
lorenzo.stoakes, akpm
The patch titled
Subject: mm: refactor map_deny_write_exec()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-refactor-map_deny_write_exec.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-refactor-map_deny_write_exec.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Subject: mm: refactor map_deny_write_exec()
Date: Wed, 23 Oct 2024 21:38:28 +0100
Refactor the map_deny_write_exec() to not unnecessarily require a VMA
parameter but rather to accept VMA flags parameters, which allows us to
use this function early in mmap_region() in a subsequent commit.
While we're here, we refactor the function to be more readable and add
some additional documentation.
Link: https://lkml.kernel.org/r/e82d23cebaa87fe5b767fecf9e730e0059066e63.1729715266.git.lorenzo.stoakes@oracle.com
Fixes: deb0f6562884 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mman.h | 21 ++++++++++++++++++---
mm/mmap.c | 2 +-
mm/mprotect.c | 2 +-
mm/vma.h | 2 +-
4 files changed, 21 insertions(+), 6 deletions(-)
--- a/include/linux/mman.h~mm-refactor-map_deny_write_exec
+++ a/include/linux/mman.h
@@ -188,16 +188,31 @@ static inline bool arch_memory_deny_writ
*
* d) mmap(PROT_READ | PROT_EXEC)
* mmap(PROT_READ | PROT_EXEC | PROT_BTI)
+ *
+ * This is only applicable if the user has set the Memory-Deny-Write-Execute
+ * (MDWE) protection mask for the current process.
+ *
+ * @old specifies the VMA flags the VMA originally possessed, and @new the ones
+ * we propose to set.
+ *
+ * Return: false if proposed change is OK, true if not ok and should be denied.
*/
-static inline bool map_deny_write_exec(struct vm_area_struct *vma, unsigned long vm_flags)
+static inline bool map_deny_write_exec(unsigned long old, unsigned long new)
{
+ /* If MDWE is disabled, we have nothing to deny. */
if (!test_bit(MMF_HAS_MDWE, ¤t->mm->flags))
return false;
- if ((vm_flags & VM_EXEC) && (vm_flags & VM_WRITE))
+ /* If the new VMA is not executable, we have nothing to deny. */
+ if (!(new & VM_EXEC))
+ return false;
+
+ /* Under MDWE we do not accept newly writably executable VMAs... */
+ if (new & VM_WRITE)
return true;
- if (!(vma->vm_flags & VM_EXEC) && (vm_flags & VM_EXEC))
+ /* ...nor previously non-executable VMAs becoming executable. */
+ if (!(old & VM_EXEC))
return true;
return false;
--- a/mm/mmap.c~mm-refactor-map_deny_write_exec
+++ a/mm/mmap.c
@@ -1504,7 +1504,7 @@ unsigned long mmap_region(struct file *f
vma_set_anonymous(vma);
}
- if (map_deny_write_exec(vma, vma->vm_flags)) {
+ if (map_deny_write_exec(vma->vm_flags, vma->vm_flags)) {
error = -EACCES;
goto close_and_free_vma;
}
--- a/mm/mprotect.c~mm-refactor-map_deny_write_exec
+++ a/mm/mprotect.c
@@ -810,7 +810,7 @@ static int do_mprotect_pkey(unsigned lon
break;
}
- if (map_deny_write_exec(vma, newflags)) {
+ if (map_deny_write_exec(vma->vm_flags, newflags)) {
error = -EACCES;
break;
}
--- a/mm/vma.h~mm-refactor-map_deny_write_exec
+++ a/mm/vma.h
@@ -42,7 +42,7 @@ struct vma_munmap_struct {
int vma_count; /* Number of vmas that will be removed */
bool unlock; /* Unlock after the munmap */
bool clear_ptes; /* If there are outstanding PTE to be cleared */
- /* 1 byte hole */
+ /* 2 byte hole */
unsigned long nr_pages; /* Number of pages being removed */
unsigned long locked_vm; /* Number of locked pages */
unsigned long nr_accounted; /* Number of VM_ACCOUNT pages */
_
Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are
fork-do-not-invoke-uffd-on-fork-if-error-occurs.patch
fork-only-invoke-khugepaged-ksm-hooks-if-no-error.patch
mm-vma-add-expand-only-vma-merge-mode-and-optimise-do_brk_flags.patch
tools-testing-add-expand-only-mode-vma-test.patch
mm-avoid-unsafe-vma-hook-invocation-when-error-arises-on-mmap-hook.patch
mm-unconditionally-close-vmas-on-error.patch
mm-refactor-map_deny_write_exec.patch
mm-resolve-faulty-mmap_region-error-path-behaviour.patch
tools-testing-add-additional-vma_internalh-stubs.patch
mm-isolate-mmap-internal-logic-to-mm-vmac.patch
mm-refactor-__mmap_region.patch
mm-defer-second-attempt-at-merge-on-mmap.patch
selftests-mm-add-pkey_sighandler_xx-hugetlb_dio-to-gitignore.patch
mm-refactor-mm_access-to-not-return-null.patch
mm-refactor-mm_access-to-not-return-null-fix.patch
mm-madvise-unrestrict-process_madvise-for-current-process.patch
maple_tree-do-not-hash-pointers-on-dump-in-debug-mode.patch
tools-testing-fix-phys_addr_t-size-on-64-bit-systems.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + mm-refactor-map_deny_write_exec.patch added to mm-hotfixes-unstable branch
@ 2024-10-30 0:36 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2024-10-30 0:36 UTC (permalink / raw)
To: mm-commits, will, vbabka, torvalds, stable, peterx, Liam.Howlett,
jannh, James.Bottomley, deller, davem, catalin.marinas, broonie,
andreas, lorenzo.stoakes, akpm
The patch titled
Subject: mm: refactor map_deny_write_exec()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-refactor-map_deny_write_exec.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-refactor-map_deny_write_exec.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Subject: mm: refactor map_deny_write_exec()
Date: Tue, 29 Oct 2024 18:11:46 +0000
Refactor the map_deny_write_exec() to not unnecessarily require a VMA
parameter but rather to accept VMA flags parameters, which allows us to
use this function early in mmap_region() in a subsequent commit.
While we're here, we refactor the function to be more readable and add
some additional documentation.
Link: https://lkml.kernel.org/r/6be8bb59cd7c68006ebb006eb9d8dc27104b1f70.1730224667.git.lorenzo.stoakes@oracle.com
Fixes: deb0f6562884 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mman.h | 21 ++++++++++++++++++---
mm/mmap.c | 2 +-
mm/mprotect.c | 2 +-
mm/vma.h | 2 +-
4 files changed, 21 insertions(+), 6 deletions(-)
--- a/include/linux/mman.h~mm-refactor-map_deny_write_exec
+++ a/include/linux/mman.h
@@ -188,16 +188,31 @@ static inline bool arch_memory_deny_writ
*
* d) mmap(PROT_READ | PROT_EXEC)
* mmap(PROT_READ | PROT_EXEC | PROT_BTI)
+ *
+ * This is only applicable if the user has set the Memory-Deny-Write-Execute
+ * (MDWE) protection mask for the current process.
+ *
+ * @old specifies the VMA flags the VMA originally possessed, and @new the ones
+ * we propose to set.
+ *
+ * Return: false if proposed change is OK, true if not ok and should be denied.
*/
-static inline bool map_deny_write_exec(struct vm_area_struct *vma, unsigned long vm_flags)
+static inline bool map_deny_write_exec(unsigned long old, unsigned long new)
{
+ /* If MDWE is disabled, we have nothing to deny. */
if (!test_bit(MMF_HAS_MDWE, ¤t->mm->flags))
return false;
- if ((vm_flags & VM_EXEC) && (vm_flags & VM_WRITE))
+ /* If the new VMA is not executable, we have nothing to deny. */
+ if (!(new & VM_EXEC))
+ return false;
+
+ /* Under MDWE we do not accept newly writably executable VMAs... */
+ if (new & VM_WRITE)
return true;
- if (!(vma->vm_flags & VM_EXEC) && (vm_flags & VM_EXEC))
+ /* ...nor previously non-executable VMAs becoming executable. */
+ if (!(old & VM_EXEC))
return true;
return false;
--- a/mm/mmap.c~mm-refactor-map_deny_write_exec
+++ a/mm/mmap.c
@@ -1505,7 +1505,7 @@ unsigned long mmap_region(struct file *f
vma_set_anonymous(vma);
}
- if (map_deny_write_exec(vma, vma->vm_flags)) {
+ if (map_deny_write_exec(vma->vm_flags, vma->vm_flags)) {
error = -EACCES;
goto close_and_free_vma;
}
--- a/mm/mprotect.c~mm-refactor-map_deny_write_exec
+++ a/mm/mprotect.c
@@ -810,7 +810,7 @@ static int do_mprotect_pkey(unsigned lon
break;
}
- if (map_deny_write_exec(vma, newflags)) {
+ if (map_deny_write_exec(vma->vm_flags, newflags)) {
error = -EACCES;
break;
}
--- a/mm/vma.h~mm-refactor-map_deny_write_exec
+++ a/mm/vma.h
@@ -42,7 +42,7 @@ struct vma_munmap_struct {
int vma_count; /* Number of vmas that will be removed */
bool unlock; /* Unlock after the munmap */
bool clear_ptes; /* If there are outstanding PTE to be cleared */
- /* 1 byte hole */
+ /* 2 byte hole */
unsigned long nr_pages; /* Number of pages being removed */
unsigned long locked_vm; /* Number of locked pages */
unsigned long nr_accounted; /* Number of VM_ACCOUNT pages */
_
Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are
mm-avoid-unsafe-vma-hook-invocation-when-error-arises-on-mmap-hook.patch
mm-unconditionally-close-vmas-on-error.patch
mm-refactor-map_deny_write_exec.patch
mm-refactor-arch_calc_vm_flag_bits-and-arm64-mte-handling.patch
mm-resolve-faulty-mmap_region-error-path-behaviour.patch
selftests-mm-add-pkey_sighandler_xx-hugetlb_dio-to-gitignore.patch
mm-refactor-mm_access-to-not-return-null.patch
mm-refactor-mm_access-to-not-return-null-fix.patch
mm-madvise-unrestrict-process_madvise-for-current-process.patch
maple_tree-do-not-hash-pointers-on-dump-in-debug-mode.patch
tools-testing-fix-phys_addr_t-size-on-64-bit-systems.patch
tools-testing-fix-phys_addr_t-size-on-64-bit-systems-fix.patch
tools-testing-add-additional-vma_internalh-stubs.patch
mm-isolate-mmap-internal-logic-to-mm-vmac.patch
mm-refactor-__mmap_region.patch
mm-remove-unnecessary-reset-state-logic-on-merge-new-vma.patch
mm-defer-second-attempt-at-merge-on-mmap.patch
mm-defer-second-attempt-at-merge-on-mmap-fix.patch
mm-pagewalk-add-the-ability-to-install-ptes.patch
mm-add-pte_marker_guard-pte-marker.patch
mm-madvise-implement-lightweight-guard-page-mechanism.patch
tools-testing-update-tools-uapi-header-for-mman-commonh.patch
selftests-mm-add-self-tests-for-guard-page-feature.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-10-30 0:36 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-10-30 0:36 + mm-refactor-map_deny_write_exec.patch added to mm-hotfixes-unstable branch Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2024-10-23 22:44 Andrew Morton
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).