Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"s390:
- Lots of small and not-so-small fixes for the newly rewritten gmap,
mostly affecting the handling of nested guests.
x86:
- Fix an issue with shadow paging, which causes KVM to install an
MMIO PTE in the shadow page tables without first zapping a non-MMIO
SPTE if KVM didn't see the write that modified the shadowed guest
PTE.
While commit a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs
directly in mmu_set_spte()") was right about it being impossible to
miss such a write if it was coming from the guest, it failed to
account for writes to guest memory that are outside the scope of
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Merge tag 'for-linus-7.0a-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fix from Juergen Gross:
"A single fix for a very rare bug introduced in rc5"
* tag 'for-linus-7.0a-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/privcmd: unregister xenstore notifier on module exit
Merge tag 'x86-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Fix an early boot crash in AMD SEV-SNP guests, caused by incorrect
FSGSBASE init ordering (Nikunj A Dadhania)
- Remove X86_CR4_FRED from the CR4 pinned bits mask, to fix a race
window during the bootup of SEV-{ES,SNP} or TDX guests, which can
crash them if they trigger exceptions in that window (Borislav
Petkov)
- Fix early boot failures on SEV-ES/SNP guests, due to incorrect early
GHCB access (Nikunj A Dadhania)
- Add clarifying comment to the CRn pinning logic, to avoid future
confusion & bugs (Peter Zijlstra)
* tag 'x86-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
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Merge tag 'timers-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
"Fix an argument order bug in the alarm timer forwarding logic, which
may cause missed expirations or incorrect overrun accounting"
* tag 'timers-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
alarmtimer: Fix argument order in alarm_timer_forward()
Merge tag 'locking-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fixes from Ingo Molnar:
- Tighten up the sys_futex_requeue() ABI a bit, to disallow dissimilar
futex flags and potential UaF access (Peter Zijlstra)
- Fix UaF between futex_key_to_node_opt() and vma_replace_policy()
(Hao-Yu Yang)
- Clear stale exiting pointer in futex_lock_pi() retry path, which
triggered a warning (and potential misbehavior) in stress-testing
(Davidlohr Bueso)
* tag 'locking-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Clear stale exiting pointer in futex_lock_pi() retry path
futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()
futex: Require sys_futex_requeue() to have identical flags
Merge tag 'ovl-fixes-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs fixes from Amir Goldstein:
- Fix regression in 'xino' feature detection
I clumsily introduced this regression myself when working on another
subsystem (fsnotify). Both the regression and the fix have almost no
visible impact on users except for some kmsg prints.
- Fix to performance regression in v6.12.
This regression was reported by Google COS developers.
It is not uncommon these days for the year-old mature LTS to get
adopted by distros and get exposed to many new workloads. We made a
sub-smart move of making a behavior change in v6.12 which could
impact performance, without making it opt-in. Fixing this mistake
retroactively, to be picked by LTS.
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Merge tag 'ext4_for_linus-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
- Update the MAINTAINERS file to add reviewers for the ext4 file system
- Add a test issue an ext4 warning (not a WARN_ON) if there are still
dirty pages attached to an evicted inode.
- Fix a number of Syzkaller issues
- Fix memory leaks on error paths
- Replace some BUG and WARN with EFSCORRUPTED reporting
- Fix a potential crash when disabling discard via remount followed by
an immediate unmount. (Found by Sashiko)
- Fix a corner case which could lead to allocating blocks for an
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Merge tag 'for-7.0-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more fixes. There's one that stands out in size as it fixes an
edge case in fsync.
- fix issue on fsync where file with zero size appears as a non-zero
after log replay
- in zlib compression, handle a crash when data alignment causes
folio reference issues
- fix possible crash with enabled tracepoints on a overlayfs mount
- handle device stats update error
- on zoned filesystems, fix kobject leak on sub-block groups
- fix super block offset in an error message in validation"
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Merge tag 'mm-hotfixes-stable-2026-03-28-10-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"10 hotfixes. 8 are cc:stable. 9 are for MM.
There's a 3-patch series of DAMON fixes from Josh Law and SeongJae
Park. The rest are singletons - please see the changelogs for details"
* tag 'mm-hotfixes-stable-2026-03-28-10-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/mseal: update VMA end correctly on merge
bug: avoid format attribute warning for clang as well
mm/pagewalk: fix race between concurrent split and refault
mm/memory: fix PMD/PUD checks in follow_pfnmap_start()
mm/damon/sysfs: check contexts->nr in repeat_call_fn
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure
mm/swap: fix swap cache memcg accounting
MAINTAINERS, mailmap: update email address for Harry Yoo
mm/huge_memory: fix folio isn't locked in softleaf_to_folio()
Merge tag 'trace-v7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix potential deadlock in osnoise and hotplug
The interface_lock can be called by a osnoise thread and the CPU
shutdown logic of osnoise can wait for this thread to finish. But
cpus_read_lock() can also be taken while holding the interface_lock.
This produces a circular lock dependency and can cause a deadlock.
Swap the ordering of cpus_read_lock() and the interface_lock to have
interface_lock taken within the cpus_read_lock() context to prevent
this circular dependency.
- Fix freeing of event triggers in early boot up
If the same trigger is added on the kernel command line, the second
one will fail to be applied and the trigger created will be freed.
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Merge tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Add array_index_nospec() to syscall dispatch table lookup to prevent
limited speculative out-of-bounds access with user-controlled syscall
number
- Mark array_index_mask_nospec() __always_inline since GCC may emit an
out-of-line call instead of the inline data dependency sequence the
mitigation relies on
- Clear r12 on kernel entry to prevent potential speculative use of
user value in system_call, ext/io/mcck interrupt handlers
* tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/entry: Scrub r12 register on kernel entry
s390/syscalls: Add spectre boundary for syscall dispatch table
s390/barrier: Make array_index_mask_nospec() __always_inline
futex: Clear stale exiting pointer in futex_lock_pi() retry path
Fuzzying/stressing futexes triggered:
WARNING: kernel/futex/core.c:825 at wait_for_owner_exiting+0x7a/0x80, CPU#11: futex_lock_pi_s/524
When futex_lock_pi_atomic() sees the owner is exiting, it returns -EBUSY
and stores a refcounted task pointer in 'exiting'.
After wait_for_owner_exiting() consumes that reference, the local pointer
is never reset to nil. Upon a retry, if futex_lock_pi_atomic() returns a
different error, the bogus pointer is passed to wait_for_owner_exiting().
CPU0 CPU1 CPU2
futex_lock_pi(uaddr)
// acquires the PI futex
exit()
futex_cleanup_begin()
futex_state = EXITING;
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tracing: Drain deferred trigger frees if kthread creation fails
Boot-time trigger registration can fail before the trigger-data cleanup
kthread exists. Deferring those frees until late init is fine, but the
post-boot fallback must still drain the deferred list if kthread
creation never succeeds.
Otherwise, boot-deferred nodes can accumulate on
trigger_data_free_list, later frees fall back to synchronously freeing
only the current object, and the older queued entries are leaked
forever.
To trigger this, add the following to the kernel command line:
trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon
The second traceon trigger will fail and be freed. This triggers a NULL
pointer dereference and crashes the kernel.
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mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Multiple sysfs command paths dereference contexts_arr[0] without first
verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to
0 via sysfs while DAMON is running, causing NULL pointer dereferences.
In more detail, the issue can be triggered by privileged users like
below.
First, start DAMON and make contexts directory empty
(kdamond->contexts->nr == 0).
# damo start
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/nr_contexts
Then, each of below commands will cause the NULL pointer dereference.
# echo update_schemes_stats > state
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mm/memory: fix PMD/PUD checks in follow_pfnmap_start()
follow_pfnmap_start() suffers from two problems:
(1) We are not re-fetching the pmd/pud after taking the PTL
Therefore, we are not properly stabilizing what the lock actually
protects. If there is concurrent zapping, we would indicate to the
caller that we found an entry, however, that entry might already have
been invalidated, or contain a different PFN after taking the lock.
Properly use pmdp_get() / pudp_get() after taking the lock.
(2) pmd_leaf() / pud_leaf() are not well defined on non-present entries
pmd_leaf()/pud_leaf() could wrongly trigger on non-present entries.
There is no real guarantee that pmd_leaf()/pud_leaf() returns something
reasonable on non-present entries. Most architectures indeed either
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mm/damon/sysfs: check contexts->nr in repeat_call_fn
damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),
damon_sysfs_upd_schemes_stats(), and
damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr.
If nr_contexts is set to 0 via sysfs while DAMON is running, these
functions dereference contexts_arr[0] and cause a NULL pointer
dereference. Add the missing check.
For example, the issue can be reproduced using DAMON sysfs interface and
DAMON user-space tool (damo) [1] like below.
$ sudo damo start --refresh_interval 1s
$ echo 0 | sudo tee \
/sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts
Link: https://patch.msgid.link/20260320163559.178101-3-objecting@objecting.org
Link: https://lkml.kernel.org/r/20260321175427.86000-4-sj@kernel.org
Link: https://github.com/damonitor/damo [1]
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bug: avoid format attribute warning for clang as well
Like gcc, clang-22 now also warns about a function that it incorrectly
identifies as a printf-style format:
lib/bug.c:190:22: error: diagnostic behavior may be improved by adding the 'format(printf, 1, 0)' attribute to the declaration of '__warn_printf' [-Werror,-Wmissing-format-attribute]
179 | static void __warn_printf(const char *fmt, struct pt_regs *regs)
| __attribute__((format(printf, 1, 0)))
180 | {
181 | if (!fmt)
182 | return;
183 |
184 | #ifdef HAVE_ARCH_BUG_FORMAT_ARGS
185 | if (regs) {
186 | struct arch_va_list _args;
187 | va_list *args = __warn_args(&_args, regs);
188 |
189 | if (args) {
190 | vprintk(fmt, *args);
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mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
This will trigger a kernel BUG:
vfio-pci 0000:03:00.0: enabling device (0000 -> 0002)
BUG: unable to handle page fault for address: ffffa23980000000
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
...
RIP: 0010:walk_pgd_range+0x3b5/0x7a0
Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24
28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 <49> f7 06
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mm/mseal: update VMA end correctly on merge
Previously we stored the end of the current VMA in curr_end, and then upon
iterating to the next VMA updated curr_start to curr_end to advance to the
next VMA.
However, this doesn't take into account the fact that a VMA might be
updated due to a merge by vma_modify_flags(), which can result in curr_end
being stale and thus, upon setting curr_start to curr_end, ending up with
an incorrect curr_start on the next iteration.
Resolve the issue by setting curr_end to vma->vm_end unconditionally to
ensure this value remains updated should this occur.
While we're here, eliminate this entire class of bug by simply setting
const curr_[start/end] to be clamped to the input range and VMAs, which
also happens to simplify the logic.
Link: https://lkml.kernel.org/r/20260327173104.322405-1-ljs@kernel.org
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mm/swap: fix swap cache memcg accounting
The swap readahead path was recently refactored and while doing this, the
order between the charging of the folio in the memcg and the addition of
the folio in the swap cache was inverted.
Since the accounting of the folio is done while adding the folio to the
swap cache and the folio is not charged in the memcg yet, the accounting
is then done at the node level, which is wrong.
Fix this by charging the folio in the memcg before adding it to the swap cache.
Link: https://lkml.kernel.org/r/20260320050601.1833108-1-alex@ghiti.fr
Fixes: 2732acda82c9 ("mm, swap: use swap cache as the swap in synchronize layer")
Signed-off-by: Alexandre Ghiti <alex at ghiti.fr>
Acked-by: Kairui Song <kasong at tencent.com>
Acked-by: Johannes Weiner <hannes at cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs at gmail.com>
Acked-by: Chris Li <chrisl at kernel.org>
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mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure
Patch series "mm/damon/sysfs: fix memory leak and NULL dereference
issues", v4.
DAMON_SYSFS can leak memory under allocation failure, and do NULL pointer
dereference when a privileged user make wrong sequences of control. Fix
those.
This patch (of 3):
When damon_sysfs_new_test_ctx() fails in damon_sysfs_commit_input(),
param_ctx is leaked because the early return skips the cleanup at the out
label. Destroy param_ctx before returning.
Link: https://lkml.kernel.org/r/20260321175427.86000-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20260321175427.86000-2-sj@kernel.org
Fixes: f0c5118ebb0e ("mm/damon/sysfs: catch commit test ctx alloc failure")
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mm/huge_memory: fix folio isn't locked in softleaf_to_folio()
On arm64 server, we found folio that get from migration entry isn't locked
in softleaf_to_folio(). This issue triggers when mTHP splitting and
zap_nonpresent_ptes() races, and the root cause is lack of memory barrier
in softleaf_to_folio(). The race is as follows:
CPU0 CPU1
deferred_split_scan() zap_nonpresent_ptes()
lock folio
split_folio()
unmap_folio()
change ptes to migration entries
__split_folio_to_order() softleaf_to_folio()
set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry))
smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio))
prep_compound_page() for tail pages
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MAINTAINERS, mailmap: update email address for Harry Yoo
Update my email address to harry at kernel.org.
Link: https://lkml.kernel.org/r/20260320125925.2259998-1-harry@kernel.org
Signed-off-by: Harry Yoo (Oracle) <harry at kernel.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
ext4: always drain queued discard work in ext4_mb_release()
While reviewing recent ext4 patch[1], Sashiko raised the following
concern[2]:
> If the filesystem is initially mounted with the discard option,
> deleting files will populate sbi->s_discard_list and queue
> s_discard_work. If it is then remounted with nodiscard, the
> EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is
> neither cancelled nor flushed.
[1] https://lore.kernel.org/r/20260319094545.19291-1-qiang.zhang@linux.dev/
[2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev
The concern was valid, but it had nothing to do with the patch[1].
One of the problems with Sashiko in its current (early) form is that
it will detect pre-existing issues and report it as a problem with the
patch that it is reviewing.
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ext4: handle wraparound when searching for blocks for indirect mapped blocks
Commit 4865c768b563 ("ext4: always allocate blocks only from groups
inode can use") restricts what blocks will be allocated for indirect
block based files to block numbers that fit within 32-bit block
numbers.
However, when using a review bot running on the latest Gemini LLM to
check this commit when backporting into an LTS based kernel, it raised
this concern:
If ac->ac_g_ex.fe_group is >= ngroups (for instance, if the goal
group was populated via stream allocation from s_mb_last_groups),
then start will be >= ngroups.
Does this allow allocating blocks beyond the 32-bit limit for
indirect block mapped files? The commit message mentions that
ext4_mb_scan_groups_linear() takes care to not select unsupported
groups. However, its loop uses group = *start, and the very first
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ext4: skip split extent recovery on corruption
ext4_split_extent_at() retries after ext4_ext_insert_extent() fails by
refinding the original extent and restoring its length. That recovery is
only safe for transient resource failures such as -ENOSPC, -EDQUOT, and
-ENOMEM.
When ext4_ext_insert_extent() fails because the extent tree is already
corrupted, ext4_find_extent() can return a leaf path without p_ext.
ext4_split_extent_at() then dereferences path[depth].p_ext while trying to
fix up the original extent length, causing a NULL pointer dereference while
handling a pre-existing filesystem corruption.
Do not enter the recovery path for corruption errors, and validate p_ext
after refinding the extent before touching it. This keeps the recovery path
limited to cases it can actually repair and turns the syzbot-triggered crash
into a proper corruption report.
Fixes: 716b9c23b862 ("ext4: refactor split and convert extents")
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ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths
During code review, Joseph found that ext4_fc_replay_inode() calls
ext4_get_fc_inode_loc() to get the inode location, which holds a
reference to iloc.bh that must be released via brelse().
However, several error paths jump to the 'out' label without
releasing iloc.bh:
- ext4_handle_dirty_metadata() failure
- sync_dirty_buffer() failure
- ext4_mark_inode_used() failure
- ext4_iget() failure
Fix this by introducing an 'out_brelse' label placed just before
the existing 'out' label to ensure iloc.bh is always released.
Additionally, make ext4_fc_replay_inode() propagate errors
properly instead of always returning 0.
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ext4: fix deadlock on inode reallocation
Currently there is a race in ext4 when reallocating freed inode
resulting in a deadlock:
Task1 Task2
ext4_evict_inode()
handle = ext4_journal_start();
...
if (IS_SYNC(inode))
handle->h_sync = 1;
ext4_free_inode()
ext4_new_inode()
handle = ext4_journal_start()
finds the bit in inode bitmap
already clear
insert_inode_locked()
waits for inode to be
removed from the hash.
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ext4: fix use-after-free in update_super_work when racing with umount
Commit b98535d09179 ("ext4: fix bug_on in start_this_handle during umount
filesystem") moved ext4_unregister_sysfs() before flushing s_sb_upd_work
to prevent new error work from being queued via /proc/fs/ext4/xx/mb_groups
reads during unmount. However, this introduced a use-after-free because
update_super_work calls ext4_notify_error_sysfs() -> sysfs_notify() which
accesses the kobject's kernfs_node after it has been freed by kobject_del()
in ext4_unregister_sysfs():
update_super_work ext4_put_super
----------------- --------------
ext4_unregister_sysfs(sb)
kobject_del(&sbi->s_kobj)
__kobject_del()
sysfs_remove_dir()
kobj->sd = NULL
sysfs_put(sd)
kernfs_put() // RCU free
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