* FAILED: patch "[PATCH] mm/hugetlb: fix mremap move length truncation" failed to apply to 6.1-stable tree
@ 2026-11-10 1:16 Sasha Levin
2026-11-14 21:34 ` [PATCH 6.1.y 1/2] mm: hugetlb: move hugeltb sysctls to its own file Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: Sasha Levin @ 2026-11-10 1:16 UTC (permalink / raw)
To: lizhe.67, akpm, david, muchun.song, osalvador, peterx, rppt,
azpijr; +Cc: stable
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x dfb190302d2b4af86c6ae48af0d3b09f28b35460
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261109201650-failed-6.1-dfb190302d2b@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'
Thanks,
Sasha
------------------ original commit in Linus's tree ------------------
From dfb190302d2b4af86c6ae48af0d3b09f28b35460 Mon Sep 17 00:00:00 2001
From: Li Zhe <lizhe.67@bytedance.com>
Date: Thu, 22 Oct 2026 11:45:41 +0800
Subject: [PATCH] mm/hugetlb: fix mremap move length truncation
Patch series "mm/hugetlb: fix mremap bugs", v3.
This series fixes a few hugetlb mremap bugs.
Patch 1 fixes the return type of move_hugetlb_page_tables(), so large
hugetlb moves cannot be truncated when reported back to the generic
mremap code.
Patch 2 disables hugetlb PMD sharing for UFFD missing mode, so
UFFDIO_POISON markers cannot become visible through shared PMD page
tables.
Patch 3 fixes the recursive i_mmap_rwsem deadlock in the hugetlb mremap
path by avoiding the destination PMD sharing allocation path while the
mapping lock is already held for write.
This patch (of 3):
move_hugetlb_page_tables() returns the number of bytes moved, but
its return type is int while the generic move_page_tables() path uses
unsigned long lengths.
A hugetlb mremap() move length above INT_MAX can therefore be
misreported to copy_vma_and_data(). The out-of-range conversion to int
is implementation-defined; on common 64-bit builds, for example, a
4 GiB move can be reported as zero, making the caller treat the move as
a failure and use the wrong length for rollback.
Return unsigned long from move_hugetlb_page_tables(), matching
move_page_tables() and preserving the full byte count.
Link: https://lore.kernel.org/20261022034543.51226-1-lizhe.67@bytedance.com
Link: https://lore.kernel.org/20261022034543.51226-2-lizhe.67@bytedance.com
Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jose A. Perez de Azpillaga <azpijr@gmail.com>
Cc: <stable@vger.kernel.org>
---
include/linux/hugetlb.h | 15 ++++++---------
mm/hugetlb.c | 7 +++----
2 files changed, 9 insertions(+), 13 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 5029c72418631..58f755e70e966 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -121,10 +121,9 @@ void hugepage_put_subpool(struct hugepage_subpool *spool);
void hugetlb_dup_vma_private(struct vm_area_struct *vma);
void clear_vma_resv_huge_pages(struct vm_area_struct *vma);
-int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr, unsigned long new_addr,
- unsigned long len);
+unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len);
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
struct vm_area_struct *, struct vm_area_struct *);
void unmap_hugepage_range(struct vm_area_struct *,
@@ -338,11 +337,9 @@ static inline int copy_hugetlb_page_range(struct mm_struct *dst,
return 0;
}
-static inline int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr,
- unsigned long new_addr,
- unsigned long len)
+static inline unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len)
{
BUG();
return 0;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index da5d04edf7c10..506729ebaee75 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5195,10 +5195,9 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
spin_unlock(dst_ptl);
}
-int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr, unsigned long new_addr,
- unsigned long len)
+unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len)
{
struct hstate *h = hstate_vma(vma);
struct address_space *mapping = vma->vm_file->f_mapping;
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 6.1.y 1/2] mm: hugetlb: move hugeltb sysctls to its own file
2026-11-10 1:16 FAILED: patch "[PATCH] mm/hugetlb: fix mremap move length truncation" failed to apply to 6.1-stable tree Sasha Levin
@ 2026-11-14 21:34 ` Sasha Levin
2026-11-14 21:34 ` [PATCH 6.1.y 2/2] mm/hugetlb: fix mremap move length truncation Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: Sasha Levin @ 2026-11-14 21:34 UTC (permalink / raw)
To: stable
Cc: Kefeng Wang, Luis Chamberlain, Mike Kravetz, Muchun Song,
Sasha Levin
From: Kefeng Wang <wangkefeng.wang@huawei.com>
[ Upstream commit 962de54828c5bb100eb8de881b79ed9c8b7468c0 ]
This moves all hugetlb sysctls to its own file, also kill an
useless hugetlb_treat_movable_handler() defination.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Stable-dep-of: dfb190302d2b ("mm/hugetlb: fix mremap move length truncation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/hugetlb.h | 8 -------
kernel/sysctl.c | 32 --------------------------
mm/hugetlb.c | 51 ++++++++++++++++++++++++++++++++++++++---
3 files changed, 48 insertions(+), 43 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index aa089e58bc41f..a9f175cda955c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -137,14 +137,6 @@ void hugepage_put_subpool(struct hugepage_subpool *spool);
void hugetlb_dup_vma_private(struct vm_area_struct *vma);
void clear_vma_resv_huge_pages(struct vm_area_struct *vma);
-int hugetlb_sysctl_handler(struct ctl_table *, int, void *, size_t *, loff_t *);
-int hugetlb_overcommit_handler(struct ctl_table *, int, void *, size_t *,
- loff_t *);
-int hugetlb_treat_movable_handler(struct ctl_table *, int, void *, size_t *,
- loff_t *);
-int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int, void *, size_t *,
- loff_t *);
-
int move_hugetlb_page_tables(struct vm_area_struct *vma,
struct vm_area_struct *new_vma,
unsigned long old_addr, unsigned long new_addr,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 5dd6fd4b48c81..e1a964ef48617 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2162,38 +2162,6 @@ static struct ctl_table vm_table[] = {
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
-#endif
-#ifdef CONFIG_HUGETLB_PAGE
- {
- .procname = "nr_hugepages",
- .data = NULL,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = hugetlb_sysctl_handler,
- },
-#ifdef CONFIG_NUMA
- {
- .procname = "nr_hugepages_mempolicy",
- .data = NULL,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = &hugetlb_mempolicy_sysctl_handler,
- },
-#endif
- {
- .procname = "hugetlb_shm_group",
- .data = &sysctl_hugetlb_shm_group,
- .maxlen = sizeof(gid_t),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
- .procname = "nr_overcommit_hugepages",
- .data = NULL,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = hugetlb_overcommit_handler,
- },
#endif
{
.procname = "lowmem_reserve_ratio",
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9660566a1ba4b..459116c744a5a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4270,6 +4270,12 @@ static void __init hugetlb_sysfs_init(void)
hugetlb_register_all_nodes();
}
+#ifdef CONFIG_SYSCTL
+static void hugetlb_sysctl_init(void);
+#else
+static inline void hugetlb_sysctl_init(void) { }
+#endif
+
static int __init hugetlb_init(void)
{
int i;
@@ -4325,6 +4331,7 @@ static int __init hugetlb_init(void)
hugetlb_sysfs_init();
hugetlb_cgroup_file_init();
+ hugetlb_sysctl_init();
#ifdef CONFIG_SMP
num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus());
@@ -4656,7 +4663,7 @@ static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
return ret;
}
-int hugetlb_sysctl_handler(struct ctl_table *table, int write,
+static int hugetlb_sysctl_handler(struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
@@ -4665,7 +4672,7 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write,
}
#ifdef CONFIG_NUMA
-int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
+static int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
return hugetlb_sysctl_handler_common(true, table, write,
@@ -4673,7 +4680,7 @@ int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
}
#endif /* CONFIG_NUMA */
-int hugetlb_overcommit_handler(struct ctl_table *table, int write,
+static int hugetlb_overcommit_handler(struct ctl_table *table, int write,
void *buffer, size_t *length, loff_t *ppos)
{
struct hstate *h = &default_hstate;
@@ -4702,6 +4709,44 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
return ret;
}
+static struct ctl_table hugetlb_table[] = {
+ {
+ .procname = "nr_hugepages",
+ .data = NULL,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = hugetlb_sysctl_handler,
+ },
+#ifdef CONFIG_NUMA
+ {
+ .procname = "nr_hugepages_mempolicy",
+ .data = NULL,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = &hugetlb_mempolicy_sysctl_handler,
+ },
+#endif
+ {
+ .procname = "hugetlb_shm_group",
+ .data = &sysctl_hugetlb_shm_group,
+ .maxlen = sizeof(gid_t),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "nr_overcommit_hugepages",
+ .data = NULL,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = hugetlb_overcommit_handler,
+ },
+ { }
+};
+
+static void hugetlb_sysctl_init(void)
+{
+ register_sysctl_init("vm", hugetlb_table);
+}
#endif /* CONFIG_SYSCTL */
void hugetlb_report_meminfo(struct seq_file *m)
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 6.1.y 2/2] mm/hugetlb: fix mremap move length truncation
2026-11-14 21:34 ` [PATCH 6.1.y 1/2] mm: hugetlb: move hugeltb sysctls to its own file Sasha Levin
@ 2026-11-14 21:34 ` Sasha Levin
0 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2026-11-14 21:34 UTC (permalink / raw)
To: stable
Cc: Li Zhe, Andrew Morton, David Hildenbrand (Arm), Muchun Song,
Oscar Salvador, Peter Xu, Mike Rapoport,
Jose A. Perez de Azpillaga, Sasha Levin
From: Li Zhe <lizhe.67@bytedance.com>
[ Upstream commit dfb190302d2b4af86c6ae48af0d3b09f28b35460 ]
Patch series "mm/hugetlb: fix mremap bugs", v3.
This series fixes a few hugetlb mremap bugs.
Patch 1 fixes the return type of move_hugetlb_page_tables(), so large
hugetlb moves cannot be truncated when reported back to the generic
mremap code.
Patch 2 disables hugetlb PMD sharing for UFFD missing mode, so
UFFDIO_POISON markers cannot become visible through shared PMD page
tables.
Patch 3 fixes the recursive i_mmap_rwsem deadlock in the hugetlb mremap
path by avoiding the destination PMD sharing allocation path while the
mapping lock is already held for write.
This patch (of 3):
move_hugetlb_page_tables() returns the number of bytes moved, but
its return type is int while the generic move_page_tables() path uses
unsigned long lengths.
A hugetlb mremap() move length above INT_MAX can therefore be
misreported to copy_vma_and_data(). The out-of-range conversion to int
is implementation-defined; on common 64-bit builds, for example, a
4 GiB move can be reported as zero, making the caller treat the move as
a failure and use the wrong length for rollback.
Return unsigned long from move_hugetlb_page_tables(), matching
move_page_tables() and preserving the full byte count.
Link: https://lore.kernel.org/20261022034543.51226-1-lizhe.67@bytedance.com
Link: https://lore.kernel.org/20261022034543.51226-2-lizhe.67@bytedance.com
Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jose A. Perez de Azpillaga <azpijr@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/hugetlb.h | 15 ++++++---------
mm/hugetlb.c | 7 +++----
2 files changed, 9 insertions(+), 13 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index a9f175cda955c..86262b82ef8ad 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -137,10 +137,9 @@ void hugepage_put_subpool(struct hugepage_subpool *spool);
void hugetlb_dup_vma_private(struct vm_area_struct *vma);
void clear_vma_resv_huge_pages(struct vm_area_struct *vma);
-int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr, unsigned long new_addr,
- unsigned long len);
+unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len);
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
struct vm_area_struct *, struct vm_area_struct *);
long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
@@ -296,11 +295,9 @@ static inline int copy_hugetlb_page_range(struct mm_struct *dst,
return 0;
}
-static inline int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr,
- unsigned long new_addr,
- unsigned long len)
+static inline unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len)
{
BUG();
return 0;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 459116c744a5a..a833a736c6ce9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5304,10 +5304,9 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
spin_unlock(dst_ptl);
}
-int move_hugetlb_page_tables(struct vm_area_struct *vma,
- struct vm_area_struct *new_vma,
- unsigned long old_addr, unsigned long new_addr,
- unsigned long len)
+unsigned long move_hugetlb_page_tables(struct vm_area_struct *vma,
+ struct vm_area_struct *new_vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long len)
{
struct hstate *h = hstate_vma(vma);
struct address_space *mapping = vma->vm_file->f_mapping;
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-11-14 21:34 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2026-11-10 1:16 FAILED: patch "[PATCH] mm/hugetlb: fix mremap move length truncation" failed to apply to 6.1-stable tree Sasha Levin
2026-11-14 21:34 ` [PATCH 6.1.y 1/2] mm: hugetlb: move hugeltb sysctls to its own file Sasha Levin
2026-11-14 21:34 ` [PATCH 6.1.y 2/2] mm/hugetlb: fix mremap move length truncation Sasha Levin
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