From: Junrui Luo <moonafterrain(a)outlook.com>
The asd_pci_remove() function fails to synchronize with pending tasklets
before freeing the asd_ha structure, leading to a potential use-after-free
vulnerability.
When a device removal is triggered (via hot-unplug or module unload), race condition can occur.
The fix adds tasklet_kill() before freeing the asd_ha structure, ensuring
all scheduled tasklets complete before cleanup proceeds.
Reported-by: Yuhao Jiang <danisjiang(a)gmail.com>
Reported-by: Junrui Luo <moonafterrain(a)outlook.com>
Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain(a)outlook.com>
---
drivers/scsi/aic94xx/aic94xx_init.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c
index adf3d9145606..95f3620059f7 100644
--- a/drivers/scsi/aic94xx/aic94xx_init.c
+++ b/drivers/scsi/aic94xx/aic94xx_init.c
@@ -882,6 +882,9 @@ static void asd_pci_remove(struct pci_dev *dev)
asd_disable_ints(asd_ha);
+ /* Ensure all scheduled tasklets complete before freeing resources */
+ tasklet_kill(&asd_ha->seq.dl_tasklet);
+
asd_remove_dev_attrs(asd_ha);
/* XXX more here as needed */
--
2.51.1.dirty
Here are various unrelated fixes:
- Patch 1: Fix window space computation for fallback connections which
can affect ACK generation. A fix for v5.11.
- Patch 2: Avoid unneeded subflow-level drops due to unsynced received
window. A fix for v5.11.
- Patch 3: Avoid premature close for fallback connections with PREEMPT
kernels. A fix for v5.12.
- Patch 4: Reset instead of fallback in case of data in the MPTCP
out-of-order queue. A fix for v5.7.
- Patches 5-7: Avoid also sending "plain" TCP reset when closing with an
MP_FASTCLOSE. A fix for v6.1.
- Patches 8-9: Longer timeout for background connections in MPTCP Join
selftests. An additional fix for recent patches for v5.13/v6.1.
- Patches 10-11: Fix typo in a check introduce in a recent refactoring.
A fix for v6.15.
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
---
Gang Yan (2):
mptcp: fix address removal logic in mptcp_pm_nl_rm_addr
selftests: mptcp: add a check for 'add_addr_accepted'
Matthieu Baerts (NGI0) (3):
selftests: mptcp: join: fastclose: remove flaky marks
selftests: mptcp: join: endpoints: longer timeout
selftests: mptcp: join: userspace: longer timeout
Paolo Abeni (6):
mptcp: fix ack generation for fallback msk
mptcp: avoid unneeded subflow-level drops
mptcp: fix premature close in case of fallback
mptcp: do not fallback when OoO is present
mptcp: decouple mptcp fastclose from tcp close
mptcp: fix duplicate reset on fastclose
net/mptcp/options.c | 54 +++++++++++++++++++++-
net/mptcp/pm_kernel.c | 2 +-
net/mptcp/protocol.c | 59 +++++++++++++++++--------
net/mptcp/protocol.h | 3 +-
tools/testing/selftests/net/mptcp/mptcp_join.sh | 27 ++++++-----
5 files changed, 113 insertions(+), 32 deletions(-)
---
base-commit: 8e0a754b0836d996802713bbebc87bc1cc17925c
change-id: 20251117-net-mptcp-misc-fixes-6-18-rc6-835d94cdc095
Best regards,
--
Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Commit c010d47f107f ("mm: thp: split huge page to any lower order
pages") introduced an early check on the folio's order via
mapping->flags before proceeding with the split work.
This check introduced a bug: for shmem folios in the swap cache, the
mapping pointer can be NULL. Accessing mapping->flags in this state
leads directly to a NULL pointer dereference.
This commit fixes the issue by moving the check for mapping != NULL
before any attempt to access mapping->flags.
This fix necessarily changes the return value from -EBUSY to -EINVAL
when mapping is NULL. After reviewing current callers, they do not
differentiate between these two error codes, making this change safe.
Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang(a)gmail.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: <stable(a)vger.kernel.org>
---
This patch is based on current mm-new, latest commit:
056b93566a35 mm/vmalloc: warn only once when vmalloc detect invalid gfp flags
Backport note:
Current code evolved from original commit with following four changes.
We should do proper adjustment respectively on backporting.
commit c010d47f107f609b9f4d6a103b6dfc53889049e9
Author: Zi Yan <ziy(a)nvidia.com>
Date: Mon Feb 26 15:55:33 2024 -0500
mm: thp: split huge page to any lower order pages
commit 6a50c9b512f7734bc356f4bd47885a6f7c98491a
Author: Ran Xiaokai <ran.xiaokai(a)zte.com.cn>
Date: Fri Jun 7 17:40:48 2024 +0800
mm: huge_memory: fix misused mapping_large_folio_support() for anon folios
commit 9b2f764933eb5e3ac9ebba26e3341529219c4401
Author: Zi Yan <ziy(a)nvidia.com>
Date: Wed Jan 22 11:19:27 2025 -0500
mm/huge_memory: allow split shmem large folio to any lower order
commit 58729c04cf1092b87aeef0bf0998c9e2e4771133
Author: Zi Yan <ziy(a)nvidia.com>
Date: Fri Mar 7 12:39:57 2025 -0500
mm/huge_memory: add buddy allocator like (non-uniform) folio_split()
---
mm/huge_memory.c | 68 +++++++++++++++++++++++++-----------------------
1 file changed, 35 insertions(+), 33 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7c69572b6c3f..8701c3eef05f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3696,29 +3696,42 @@ bool folio_split_supported(struct folio *folio, unsigned int new_order,
"Cannot split to order-1 folio");
if (new_order == 1)
return false;
- } else if (split_type == SPLIT_TYPE_NON_UNIFORM || new_order) {
- if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
- !mapping_large_folio_support(folio->mapping)) {
- /*
- * We can always split a folio down to a single page
- * (new_order == 0) uniformly.
- *
- * For any other scenario
- * a) uniform split targeting a large folio
- * (new_order > 0)
- * b) any non-uniform split
- * we must confirm that the file system supports large
- * folios.
- *
- * Note that we might still have THPs in such
- * mappings, which is created from khugepaged when
- * CONFIG_READ_ONLY_THP_FOR_FS is enabled. But in that
- * case, the mapping does not actually support large
- * folios properly.
- */
- VM_WARN_ONCE(warns,
- "Cannot split file folio to non-0 order");
+ } else {
+ const struct address_space *mapping = folio->mapping;
+
+ /* Truncated ? */
+ /*
+ * TODO: add support for large shmem folio in swap cache.
+ * When shmem is in swap cache, mapping is NULL and
+ * folio_test_swapcache() is true.
+ */
+ if (!mapping)
return false;
+
+ if (split_type == SPLIT_TYPE_NON_UNIFORM || new_order) {
+ if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
+ !mapping_large_folio_support(folio->mapping)) {
+ /*
+ * We can always split a folio down to a
+ * single page (new_order == 0) uniformly.
+ *
+ * For any other scenario
+ * a) uniform split targeting a large folio
+ * (new_order > 0)
+ * b) any non-uniform split
+ * we must confirm that the file system
+ * supports large folios.
+ *
+ * Note that we might still have THPs in such
+ * mappings, which is created from khugepaged
+ * when CONFIG_READ_ONLY_THP_FOR_FS is
+ * enabled. But in that case, the mapping does
+ * not actually support large folios properly.
+ */
+ VM_WARN_ONCE(warns,
+ "Cannot split file folio to non-0 order");
+ return false;
+ }
}
}
@@ -3965,17 +3978,6 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
mapping = folio->mapping;
- /* Truncated ? */
- /*
- * TODO: add support for large shmem folio in swap cache.
- * When shmem is in swap cache, mapping is NULL and
- * folio_test_swapcache() is true.
- */
- if (!mapping) {
- ret = -EBUSY;
- goto out;
- }
-
min_order = mapping_min_folio_order(folio->mapping);
if (new_order < min_order) {
ret = -EINVAL;
--
2.34.1
The patch titled
Subject: mm/huge_memory: fix NULL pointer deference when splitting folio
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-huge_memory-fix-null-pointer-deference-when-splitting-folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
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: Wei Yang <richard.weiyang(a)gmail.com>
Subject: mm/huge_memory: fix NULL pointer deference when splitting folio
Date: Wed, 19 Nov 2025 23:53:02 +0000
Commit c010d47f107f ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.
This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL. Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.
This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags.
Link: https://lkml.kernel.org/r/20251119235302.24773-1-richard.weiyang@gmail.com
Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang(a)gmail.com>
Reviewed-by: Zi Yan <ziy(a)nvidia.com>
Cc: "David Hildenbrand (Red Hat)" <david(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/huge_memory.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-fix-null-pointer-deference-when-splitting-folio
+++ a/mm/huge_memory.c
@@ -3619,6 +3619,16 @@ static int __folio_split(struct folio *f
if (folio != page_folio(split_at) || folio != page_folio(lock_at))
return -EINVAL;
+ /*
+ * Folios that just got truncated cannot get split. Signal to the
+ * caller that there was a race.
+ *
+ * TODO: this will also currently refuse shmem folios that are in the
+ * swapcache.
+ */
+ if (!is_anon && !folio->mapping)
+ return -EBUSY;
+
if (new_order >= folio_order(folio))
return -EINVAL;
@@ -3659,18 +3669,6 @@ static int __folio_split(struct folio *f
gfp_t gfp;
mapping = folio->mapping;
-
- /* Truncated ? */
- /*
- * TODO: add support for large shmem folio in swap cache.
- * When shmem is in swap cache, mapping is NULL and
- * folio_test_swapcache() is true.
- */
- if (!mapping) {
- ret = -EBUSY;
- goto out;
- }
-
min_order = mapping_min_folio_order(folio->mapping);
if (new_order < min_order) {
ret = -EINVAL;
_
Patches currently in -mm which might be from richard.weiyang(a)gmail.com are
mm-huge_memory-fix-null-pointer-deference-when-splitting-folio.patch
mm-huge_memory-add-pmd-folio-to-ds_queue-in-do_huge_zero_wp_pmd.patch
mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch
mm-huge_memory-only-get-folio_order-once-during-__folio_split.patch
mm-huge_memory-introduce-enum-split_type-for-clarity.patch
mm-huge_memory-merge-uniform_split_supported-and-non_uniform_split_supported.patch
mm-khugepaged-remove-redundant-clearing-of-struct-collapse_control.patch
mm-khugepaged-continue-to-collapse-on-scan_pmd_none.patch
mm-khugepaged-unify-scan_pmd_none-and-scan_pmd_null-into-scan_no_pte_table.patch
The quilt patch titled
Subject: unshare: fix nsproxy leak on set_cred_ucounts() error path
has been removed from the -mm tree. Its filename was
unshare-fix-nsproxy-leak-on-set_cred_ucounts-error-path.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Subject: unshare: fix nsproxy leak on set_cred_ucounts() error path
Date: Tue, 18 Nov 2025 14:45:50 +0800
If unshare_nsproxy_namespaces() successfully creates the new_nsproxy, but
then set_cred_ucounts() fails, on its error path there is no cleanup for
new_nsproxy, so it is leaked. Let's fix that by freeing new_nsproxy if
it's not NULL on this error path.
Link: https://lkml.kernel.org/r/20251118064552.936962-1-ptikhomirov@virtuozzo.com
Fixes: 905ae01c4ae2 ("Add a reference to ucounts for each cred")
Signed-off-by: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Acked-by: Alexey Gladkov <legion(a)kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett(a)oracle.com>
Cc: Ben Segall <bsegall(a)google.com>
Cc: Dietmar Eggemann <dietmar.eggemann(a)arm.com>
Cc: Eric Biederman <ebiederm(a)xmission.com>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Juri Lelli <juri.lelli(a)redhat.com>
Cc: Kees Cook <kees(a)kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: Mel Gorman <mgorman <mgorman(a)suse.de>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Mike Rapoport <rppt(a)kernel.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Valentin Schneider <vschneid(a)redhat.com>
Cc: Vincent Guittot <vincent.guittot(a)linaro.org>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Christian Brauner <brauner(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
kernel/fork.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/kernel/fork.c~unshare-fix-nsproxy-leak-on-set_cred_ucounts-error-path
+++ a/kernel/fork.c
@@ -3133,8 +3133,11 @@ int ksys_unshare(unsigned long unshare_f
if (new_cred) {
err = set_cred_ucounts(new_cred);
- if (err)
+ if (err) {
+ if (new_nsproxy)
+ free_nsproxy(new_nsproxy);
goto bad_unshare_cleanup_cred;
+ }
}
if (new_fs || new_fd || do_sysvsem || new_cred || new_nsproxy) {
_
Patches currently in -mm which might be from ptikhomirov(a)virtuozzo.com are
From: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Subject: unshare: fix nsproxy leak on set_cred_ucounts() error path
Date: Tue, 18 Nov 2025 14:45:50 +0800
If unshare_nsproxy_namespaces() successfully creates the new_nsproxy, but
then set_cred_ucounts() fails, on its error path there is no cleanup for
new_nsproxy, so it is leaked. Let's fix that by freeing new_nsproxy if
it's not NULL on this error path.
Link: https://lkml.kernel.org/r/20251118064552.936962-1-ptikhomirov@virtuozzo.com
Fixes: 905ae01c4ae2a ("Add a reference to ucounts for each cred")
Signed-off-by: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Acked-by: Alexey Gladkov <legion(a)kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett(a)oracle.com>
Cc: Ben Segall <bsegall(a)google.com>
Cc: Dietmar Eggemann <dietmar.eggemann(a)arm.com>
Cc: Eric Biederman <ebiederm(a)xmission.com>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Juri Lelli <juri.lelli(a)redhat.com>
Cc: Kees Cook <kees(a)kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: Mel Gorman <mgorman <mgorman(a)suse.de>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Mike Rapoport <rppt(a)kernel.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Valentin Schneider <vschneid(a)redhat.com>
Cc: Vincent Guittot <vincent.guittot(a)linaro.org>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
kernel/fork.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/kernel/fork.c~unshare-fix-nsproxy-leak-on-set_cred_ucounts-error-path
+++ a/kernel/fork.c
@@ -3133,8 +3133,11 @@ int ksys_unshare(unsigned long unshare_f
if (new_cred) {
err = set_cred_ucounts(new_cred);
- if (err)
+ if (err) {
+ if (new_nsproxy)
+ free_nsproxy(new_nsproxy);
goto bad_unshare_cleanup_cred;
+ }
}
if (new_fs || new_fd || do_sysvsem || new_cred || new_nsproxy) {
_
# TL;DR
previous discussion: https://lore.kernel.org/linux-mm/b41ea29e-6b48-4f64-859c-73be095453ae@redha…
A "bad pmd" error occurs due to race condition between
change_prot_numa() and THP migration. The mainline kernel does not have
this bug as commit 670ddd8cdc fixes the race condition. 6.1.y, 5.15.y,
5.10.y, 5.4.y are affected by this bug.
Fixing this in -stable kernels is tricky because pte_map_offset_lock()
has different semantics in pre-6.5 and post-6.5 kernels. I am trying to
backport the same mechanism we have in the mainline kernel.
Since the code looks bit different due to different semantics of
pte_map_offset_lock(), it'd be best to get this reviewed by MM folks.
# Testing
I verified that the bug described below is not reproduced anymore
(on a downstream kernel) after applying this patch series. It used to
trigger in few days of intensive numa balancing testing, but it survived
2 weeks with this applied.
# Bug Description
It was reported that a bad pmd is seen when automatic NUMA
balancing is marking page table entries as prot_numa:
[2437548.196018] mm/pgtable-generic.c:50: bad pmd 00000000af22fc02(dffffffe71fbfe02)
[2437548.235022] Call Trace:
[2437548.238234] <TASK>
[2437548.241060] dump_stack_lvl+0x46/0x61
[2437548.245689] panic+0x106/0x2e5
[2437548.249497] pmd_clear_bad+0x3c/0x3c
[2437548.253967] change_pmd_range.isra.0+0x34d/0x3a7
[2437548.259537] change_p4d_range+0x156/0x20e
[2437548.264392] change_protection_range+0x116/0x1a9
[2437548.269976] change_prot_numa+0x15/0x37
[2437548.274774] task_numa_work+0x1b8/0x302
[2437548.279512] task_work_run+0x62/0x95
[2437548.283882] exit_to_user_mode_loop+0x1a4/0x1a9
[2437548.289277] exit_to_user_mode_prepare+0xf4/0xfc
[2437548.294751] ? sysvec_apic_timer_interrupt+0x34/0x81
[2437548.300677] irqentry_exit_to_user_mode+0x5/0x25
[2437548.306153] asm_sysvec_apic_timer_interrupt+0x16/0x1b
This is due to a race condition between change_prot_numa() and
THP migration because the kernel doesn't check is_swap_pmd() and
pmd_trans_huge() atomically:
change_prot_numa() THP migration
======================================================================
- change_pmd_range()
-> is_swap_pmd() returns false,
meaning it's not a PMD migration
entry.
- do_huge_pmd_numa_page()
-> migrate_misplaced_page() sets
migration entries for the THP.
- change_pmd_range()
-> pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_none() and pmd_trans_huge() returns false
- pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_bad() returns true for the migration entry!
The upstream commit 670ddd8cdcbd ("mm/mprotect: delete
pmd_none_or_clear_bad_unless_trans_huge()") closes this race condition
by checking is_swap_pmd() and pmd_trans_huge() atomically.
# Backporting note
commit a79390f5d6a7 ("mm/mprotect: use long for page accountings and retval")
is backported to return an error code (negative value) in
change_pte_range().
Unlike the mainline, pte_offset_map_lock() does not check if the pmd
entry is a migration entry or a hugepage; acquires PTL unconditionally
instead of returning failure. Therefore, it is necessary to keep the
!is_swap_pmd() && !pmd_trans_huge() && !pmd_devmap() checks in
change_pmd_range() before acquiring the PTL.
After acquiring the lock, open-code the semantics of
pte_offset_map_lock() in the mainline kernel; change_pte_range() fails
if the pmd value has changed. This requires adding pmd_old parameter
(pmd_t value that is read before calling the function) to
change_pte_range().
Hugh Dickins (1):
mm/mprotect: delete pmd_none_or_clear_bad_unless_trans_huge()
Peter Xu (1):
mm/mprotect: use long for page accountings and retval
include/linux/hugetlb.h | 4 +-
include/linux/mm.h | 2 +-
mm/hugetlb.c | 4 +-
mm/mempolicy.c | 2 +-
mm/mprotect.c | 125 ++++++++++++++++++----------------------
5 files changed, 61 insertions(+), 76 deletions(-)
--
2.43.0