Pull vfs fixes from Christian Brauner:
- Fix netfs_limit_iter() hitting BUG() when an ITER_KVEC iterator
reaches it via core dump writes to 9P filesystems. Add ITER_KVEC
handling following the same pattern as the existing ITER_BVEC code.
- Fix a NULL pointer dereference in the netfs unbuffered write retry
path when the filesystem (e.g., 9P) doesn't set the prepare_write
operation.
- Clear I_DIRTY_TIME in sync_lazytime for filesystems implementing
->sync_lazytime. Without this the flag stays set and may cause
additional unnecessary calls during inode deactivation.
- Increase tmpfs size in mount_setattr selftests. A recent commit
bumped the ext4 image size to 2 GB but didn't adjust the tmpfs
backing store, so mkfs.ext4 fails with ENOSPC writing metadata.
- Fix an invalid folio access in iomap when i_blkbits matches the folio
size but differs from the I/O granularity. The cur_folio pointer
would not get invalidated and iomap_read_end() would still be called
on it despite the IO helper owning it.
- Fix hash_name() docstring.
- Fix read abandonment during netfs retry where the subreq variable
used for abandonment could be uninitialized on the first pass or
point to a deleted subrequest on later passes.
- Don't block sync for filesystems with no data integrity guarantees.
Add a SB_I_NO_DATA_INTEGRITY superblock flag replacing the per-inode
AS_NO_DATA_INTEGRITY mapping flag so sync kicks off writeback but
doesn't wait for flusher threads. This fixes a suspend-to-RAM hang on
fuse-overlayfs where the flusher thread blocks when the fuse daemon
is frozen.
- Fix a lockdep splat in iomap when reads fail. iomap_read_end_io()
invokes fserror_report() which calls igrab() taking i_lock in hardirq
context while i_lock is normally held with interrupts enabled. Kick
failed read handling to a workqueue.
- Remove the redundant netfs_io_stream::front member and use
stream->subrequests.next instead, fixing a potential issue in the
direct write code path.
* tag 'vfs-7.0-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
netfs: Fix the handling of stream->front by removing it
iomap: fix lockdep complaint when reads fail
writeback: don't block sync for filesystems with no data integrity guarantees
netfs: Fix read abandonment during retry
vfs: fix docstring of hash_name()
iomap: fix invalid folio access when i_blkbits differs from I/O granularity
selftests/mount_setattr: increase tmpfs size for idmapped mount tests
fs: clear I_DIRTY_TIME in sync_lazytime
netfs: Fix NULL pointer dereference in netfs_unbuffered_write() on retry
netfs: Fix kernel BUG in netfs_limit_iter() for ITER_KVEC iterators
Pull phy fixes from Vinod Koul:
- Qualcomm PCS table fix for ufs phy
- TI device node reference fix
- Common prop kconfig fix
- lynx CDR lock workaround for lanes disabled
- usb disconnect function fix of k1 driver
* tag 'phy-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy:
phy: qcom: qmp-ufs: Fix SM8650 PCS table for Gear 4
phy: ti: j721e-wiz: Fix device node reference leak in wiz_get_lane_phy_types()
phy: k1-usb: add disconnect function support
phy: lynx-28g: skip CDR lock workaround for lanes disabled in the device tree
phy: make PHY_COMMON_PROPS Kconfig symbol conditionally user-selectable
Pull dmaengine fixes from Vinod Koul:
"A bunch of driver fixes with idxd ones being the biggest:
- Xilinx regmap init error handling, dma_device directions, residue
calculation, and reset related timeout fixes
- Renesas CHCTRL updates and driver list fixes
- DW HDMA cycle bits and MSI data programming fix
- IDXD pile of fixes for memeory leak and FLR fixes"
* tag 'dmaengine-fix-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (21 commits)
dmaengine: xilinx_dma: Fix reset related timeout with two-channel AXIDMA
dmaengine: xilinx: xilinx_dma: Fix unmasked residue subtraction
dmaengine: xilinx: xilinx_dma: Fix residue calculation for cyclic DMA
dmaengine: xilinx: xilinx_dma: Fix dma_device directions
dmaengine: sh: rz-dmac: Move CHCTRL updates under spinlock
dmaengine: sh: rz-dmac: Protect the driver specific lists
dmaengine: idxd: fix possible wrong descriptor completion in llist_abort_desc()
dmaengine: xilinx: xdma: Fix regmap init error handling
dmaengine: dw-edma: Fix multiple times setting of the CYCLE_STATE and CYCLE_BIT bits for HDMA.
dmaengine: idxd: Fix leaking event log memory
dmaengine: idxd: Fix freeing the allocated ida too late
dmaengine: idxd: Fix memory leak when a wq is reset
dmaengine: idxd: Fix not releasing workqueue on .release()
dmaengine: idxd: Wait for submitted operations on .device_synchronize()
dmaengine: idxd: Flush all pending descriptors
dmaengine: idxd: Flush kernel workqueues on Function Level Reset
dmaengine: idxd: Fix possible invalid memory access after FLR
dmaengine: idxd: Fix crash when the event log is disabled
dmaengine: idxd: Fix lockdep warnings when calling idxd_device_config()
dmaengine: dw-edma: fix MSI data programming for multi-IRQ case
...
Pull i2c fixes from Wolfram Sang:
- designware: fix resume-probe race causing NULL-deref in amdisp
- imx: fix timeout on repeated reads and extra clock at end
- MAINTAINERS: drop outdated I2C website
* tag 'i2c-for-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
MAINTAINERS: drop outdated I2C website
i2c: designware: amdisp: Fix resume-probe race condition issue
i2c: imx: ensure no clock is generated after last read
i2c: imx: fix i2c issue when reading multiple messages
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 a54aa15c6b ("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
KVM: if userspace modifies the guest PTE, and then the guest hits a
relevant page fault, KVM will get confused"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE
KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE
KVM: s390: Fix KVM_S390_VCPU_FAULT ioctl
KVM: s390: vsie: Fix guest page tables protection
KVM: s390: vsie: Fix unshadowing while shadowing
KVM: s390: vsie: Fix refcount overflow for shadow gmaps
KVM: s390: vsie: Fix nested guest memory shadowing
KVM: s390: Correctly handle guest mappings without struct page
KVM: s390: Fix gmap_link()
KVM: s390: vsie: Fix check for pre-existing shadow mapping
KVM: s390: Remove non-atomic dat_crstep_xchg()
KVM: s390: vsie: Fix dat_split_ste()
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
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:
x86/cpu: Add comment clarifying CRn pinning
x86/fred: Fix early boot failures on SEV-ES/SNP guests
x86/cpu: Remove X86_CR4_FRED from the CR4 pinned bits mask
x86/cpu: Enable FSGSBASE early in cpu_init_exception_handling()
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()
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
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.
* tag 'ovl-fixes-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: make fsync after metadata copy-up opt-in mount option
ovl: fix wrong detection of 32bit inode numbers
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
indirect-mapped inode block numbers > 2**32
- Fix a race when reallocating a freed inode that could result in a
deadlock
- Fix a user-after-free in update_super_work when racing with umount
- Fix build issues when trying to build ext4's kunit tests as a module
- Fix a bug where ext4_split_extent_zeroout() could fail to pass back
an error from ext4_ext_dirty()
- Avoid allocating blocks from a corrupted block group in
ext4_mb_find_by_goal()
- Fix a percpu_counters list corruption BUG triggered by an ext4
extents kunit
- Fix a potetial crash caused by the fast commit flush path potentially
accessing the jinode structure before it is fully initialized
- Fix fsync(2) in no-journal mode to make sure the dirtied inode is
write to storage
- Fix a bug when in no-journal mode, when ext4 tries to avoid using
recently deleted inodes, if lazy itable initialization is enabled,
can lead to an unitialized inode getting skipped and triggering an
e2fsck complaint
- Fix journal credit calculation when setting an xattr when both the
encryption and ea_inode feeatures are enabled
- Fix corner cases which could result in stale xarray tags after
writeback
- Fix generic/475 failures caused by ENOSPC errors while creating a
symlink when the system crashes resulting to a file system
inconsistency when replaying the fast commit journal
* tag 'ext4_for_linus-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (27 commits)
ext4: always drain queued discard work in ext4_mb_release()
ext4: handle wraparound when searching for blocks for indirect mapped blocks
ext4: skip split extent recovery on corruption
ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths
ext4: fix deadlock on inode reallocation
ext4: fix use-after-free in update_super_work when racing with umount
ext4: fix the might_sleep() warnings in kvfree()
ext4: reject mount if bigalloc with s_first_data_block != 0
ext4: fix extents-test.c is not compiled when EXT4_KUNIT_TESTS=M
ext4: fix mballoc-test.c is not compiled when EXT4_KUNIT_TESTS=M
ext4: introduce EXPORT_SYMBOL_FOR_EXT4_TEST() helper
jbd2: gracefully abort on checkpointing state corruptions
ext4: avoid infinite loops caused by residual data
ext4: validate p_idx bounds in ext4_ext_correct_indexes
ext4: test if inode's all dirty pages are submitted to disk
ext4: minor fix for ext4_split_extent_zeroout()
ext4: avoid allocate block from corrupted group in ext4_mb_find_by_goal()
ext4: kunit: extents-test: lix percpu_counters list corruption
ext4: publish jinode after initialization
ext4: replace BUG_ON with proper error handling in ext4_read_inline_folio
...
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"
* tag 'for-7.0-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix lost error when running device stats on multiple devices fs
btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()
btrfs: zlib: handle page aligned compressed size correctly
btrfs: fix leak of kobject name for sub-group space_info
btrfs: fix zero size inode with non-zero size after log replay
btrfs: fix super block offset in error message in btrfs_validate_super()
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()
As stated on the website: "This wiki has been archived and the content
is no longer updated." No need to reference it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
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.
This calls into the deferred logic and creates a kernel thread to do
the freeing. But the command line logic is called before kernel
threads can be created and this leads to a NULL pointer dereference.
Delay freeing event triggers until late init.
* tag 'trace-v7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Drain deferred trigger frees if kthread creation fails
tracing: Fix potential deadlock in cpu hotplug with osnoise
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
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;
futex_lock_pi(uaddr)
futex_lock_pi_atomic()
attach_to_pi_owner()
// observes EXITING
*exiting = owner; // takes ref
return -EBUSY
wait_for_owner_exiting(-EBUSY, owner)
put_task_struct(); // drops ref
// exiting still points to owner
goto retry;
futex_lock_pi_atomic()
lock_pi_update_atomic()
cmpxchg(uaddr)
*uaddr ^= WAITERS // whatever
// value changed
return -EAGAIN;
wait_for_owner_exiting(-EAGAIN, exiting) // stale
WARN_ON_ONCE(exiting)
Fix this by resetting upon retry, essentially aligning it with requeue_pi.
Fixes: 3ef240eaff ("futex: Prevent exit livelock")
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260326001759.4129680-1-dave@stgolabs.net
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.
Keep the deferred boot-time behavior, but when kthread creation fails,
drain the whole queued list synchronously. Do the same in the late-init
drain path so queued entries are not stranded there either.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260324221326.1395799-3-atwellwea@gmail.com
Fixes: 61d445af0a ("tracing: Add bulk garbage collection of freeing event_trigger_data")
Signed-off-by: Wesley Atwell <atwellwea@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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
perform a present check or make it work by smart use of flags.
However, for example loongarch checks the _PAGE_HUGE flag in pmd_leaf(),
and always sets the _PAGE_HUGE flag in __swp_entry_to_pmd(). Whereby
pmd_trans_huge() explicitly checks pmd_present(), pmd_leaf() does not do
that.
Let's check pmd_present()/pud_present() before assuming "the is a present
PMD leaf" when spotting pmd_leaf()/pud_leaf(), like other page table
handling code that traverses user page tables does.
Given that non-present PMD entries are likely rare in VM_IO|VM_PFNMAP, (1)
is likely more relevant than (2). It is questionable how often (1) would
actually trigger, but let's CC stable to be sure.
This was found by code inspection.
Link: https://lkml.kernel.org/r/20260323-follow_pfnmap_fix-v1-1-5b0ec10872b3@kernel.org
Fixes: 6da8e9634b ("mm: new follow_pfnmap API")
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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
# echo update_schemes_tried_regions > state
# echo update_schemes_tried_bytes > state
# echo update_schemes_effective_quotas > state
# echo update_tuned_intervals > state
Guard all commands (except OFF) at the entry point of
damon_sysfs_handle_cmd().
Link: https://lkml.kernel.org/r/20260321175427.86000-3-sj@kernel.org
Fixes: 0ac32b8aff ("mm/damon/sysfs: support DAMOS stats")
Signed-off-by: Josh Law <objecting@objecting.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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
In __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages
are visible before the tail page becomes non-compound. smp_wmb() should
be paired with smp_rmb() in softleaf_to_folio(), which is missed. As a
result, if zap_nonpresent_ptes() accesses migration entry that stores tail
pfn, softleaf_to_folio() may see the updated compound_head of tail page
before page->flags.
This issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio()
because of the race between folio split and zap_nonpresent_ptes()
leading to a folio incorrectly undergoing modification without a folio
lock being held.
This is a BUG_ON() before commit 93976a2034 ("mm: eliminate further
swapops predicates"), which in merged in v6.19-rc1.
To fix it, add missing smp_rmb() if the softleaf entry is migration entry
in softleaf_to_folio() and softleaf_to_page().
[tujinjiang@huawei.com: update function name and comments]
Link: https://lkml.kernel.org/r/20260321075214.3305564-1-tujinjiang@huawei.com
Link: https://lkml.kernel.org/r/20260319012541.4158561-1-tujinjiang@huawei.com
Fixes: e9b61f1985 ("thp: reintroduce split_huge_page()")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.
In practice, it would be hard to hit deliberately (unless you are a
malicious syzkaller fuzzer), since it would involve mounting the file
system with -o discard, and then deleting a large number of files,
remounting the file system with -o nodiscard, and then immediately
unmounting the file system before the queued discard work has a change
to drain on its own.
Fix it because it's a real bug, and to avoid Sashiko from raising this
concern when analyzing future patches to mballoc.c.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fixes: 55cdd0af2b ("ext4: get discard out of jbd2 commit kthread contex")
Cc: stable@kernel.org
Commit 4865c768b5 ("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
iteration will call ext4_mb_scan_group() with this unsupported
group because next_linear_group() is only called at the end of the
iteration.
After reviewing the code paths involved and considering the LLM
review, I determined that this can happen when there is a file system
where some files/directories are extent-mapped and others are
indirect-block mapped. To address this, add a safety clamp in
ext4_mb_scan_groups().
Fixes: 4865c768b5 ("ext4: always allocate blocks only from groups inode can use")
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun@linux.alibaba.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://patch.msgid.link/20260326045834.1175822-1-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
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: 716b9c23b8 ("ext4: refactor split and convert extents")
Reported-by: syzbot+1ffa5d865557e51cb604@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1ffa5d865557e51cb604
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: hongao <hongao@uniontech.com>
Link: https://patch.msgid.link/EF77870F23FF9C90+20260324015815.35248-1-hongao@uniontech.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
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.
Reported-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Fixes: 8016e29f43 ("ext4: fast commit recovery path")
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260323060836.3452660-1-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
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.
ext4_journal_stop(handle)
jbd2_journal_stop(handle)
jbd2_log_wait_commit(journal, tid);
- deadlocks waiting for transaction handle Task2 holds
Fix the problem by removing inode from the hash already in
ext4_clear_inode() by which time all IO for the inode is done so reuse
is already fine but we are still before possibly blocking on transaction
commit.
Reported-by: "Lai, Yi" <yi1.lai@linux.intel.com>
Link: https://lore.kernel.org/all/abNvb2PcrKj1FBeC@ly-workstation
Fixes: 88ec797c46 ("fs: make insert_inode_locked() wait for inode destruction")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260320090428.24899-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Commit b98535d091 ("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
ext4_notify_error_sysfs(sbi)
sysfs_notify(&sbi->s_kobj)
kn = kobj->sd // stale pointer
kernfs_get(kn) // UAF on freed kernfs_node
ext4_journal_destroy()
flush_work(&sbi->s_sb_upd_work)
Instead of reordering the teardown sequence, fix this by making
ext4_notify_error_sysfs() detect that sysfs has already been torn down
by checking s_kobj.state_in_sysfs, and skipping the sysfs_notify() call
in that case. A dedicated mutex (s_error_notify_mutex) serializes
ext4_notify_error_sysfs() against kobject_del() in ext4_unregister_sysfs()
to prevent TOCTOU races where the kobject could be deleted between the
state_in_sysfs check and the sysfs_notify() call.
Fixes: b98535d091 ("ext4: fix bug_on in start_this_handle during umount filesystem")
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260319120336.157873-1-jiayuan.chen@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
This patch targets two internal state machine invariants in checkpoint.c
residing inside functions that natively return integer error codes.
- In jbd2_cleanup_journal_tail(): A blocknr of 0 indicates a severely
corrupted journal superblock. Replaced the J_ASSERT with a WARN_ON_ONCE
and a graceful journal abort, returning -EFSCORRUPTED.
- In jbd2_log_do_checkpoint(): Replaced the J_ASSERT_BH checking for
an unexpected buffer_jwrite state. If the warning triggers, we
explicitly drop the just-taken get_bh() reference and call __flush_batch()
to safely clean up any previously queued buffers in the j_chkpt_bhs array,
preventing a memory leak before returning -EFSCORRUPTED.
Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun@linux.alibaba.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260311041548.159424-1-nikic.milos@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
On the mkdir/mknod path, when mapping logical blocks to physical blocks,
if inserting a new extent into the extent tree fails (in this example,
because the file system disabled the huge file feature when marking the
inode as dirty), ext4_ext_map_blocks() only calls ext4_free_blocks() to
reclaim the physical block without deleting the corresponding data in
the extent tree. This causes subsequent mkdir operations to reference
the previously reclaimed physical block number again, even though this
physical block is already being used by the xattr block. Therefore, a
situation arises where both the directory and xattr are using the same
buffer head block in memory simultaneously.
The above causes ext4_xattr_block_set() to enter an infinite loop about
"inserted" and cannot release the inode lock, ultimately leading to the
143s blocking problem mentioned in [1].
If the metadata is corrupted, then trying to remove some extent space
can do even more harm. Also in case EXT4_GET_BLOCKS_DELALLOC_RESERVE
was passed, remove space wrongly update quota information.
Jan Kara suggests distinguishing between two cases:
1) The error is ENOSPC or EDQUOT - in this case the filesystem is fully
consistent and we must maintain its consistency including all the
accounting. However these errors can happen only early before we've
inserted the extent into the extent tree. So current code works correctly
for this case.
2) Some other error - this means metadata is corrupted. We should strive to
do as few modifications as possible to limit damage. So I'd just skip
freeing of allocated blocks.
[1]
INFO: task syz.0.17:5995 blocked for more than 143 seconds.
Call Trace:
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
Reported-by: syzbot+512459401510e2a9a39f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1659aaaaa8d9d11265d7
Tested-by: syzbot+1659aaaaa8d9d11265d7@syzkaller.appspotmail.com
Reported-by: syzbot+1659aaaaa8d9d11265d7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=512459401510e2a9a39f
Tested-by: syzbot+1659aaaaa8d9d11265d7@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: syzbot+512459401510e2a9a39f@syzkaller.appspotmail.com
Link: https://patch.msgid.link/tencent_43696283A68450B761D76866C6F360E36705@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
The commit aa373cf550 ("writeback: stop background/kupdate works from
livelocking other works") introduced an issue where unmounting a filesystem
in a multi-logical-partition scenario could lead to batch file data loss.
This problem was not fixed until the commit d92109891f ("fs/writeback:
bail out if there is no more inodes for IO and queued once"). It took
considerable time to identify the root cause. Additionally, in actual
production environments, we frequently encountered file data loss after
normal system reboots. Therefore, we are adding a check in the inode
release flow to verify whether all dirty pages have been flushed to disk,
in order to determine whether the data loss is caused by a logic issue in
the filesystem code.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260303012242.3206465-1-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
There's issue as follows:
...
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2243 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2239 at logical offset 0 with max blocks 1 with error 117
EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost
EXT4-fs (mmcblk0p1): error count since last fsck: 1
EXT4-fs (mmcblk0p1): initial error at time 1765597433: ext4_mb_generate_buddy:760
EXT4-fs (mmcblk0p1): last error at time 1765597433: ext4_mb_generate_buddy:760
...
According to the log analysis, blocks are always requested from the
corrupted block group. This may happen as follows:
ext4_mb_find_by_goal
ext4_mb_load_buddy
ext4_mb_load_buddy_gfp
ext4_mb_init_cache
ext4_read_block_bitmap_nowait
ext4_wait_block_bitmap
ext4_validate_block_bitmap
if (!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
return -EFSCORRUPTED; // There's no logs.
if (err)
return err; // Will return error
ext4_lock_group(ac->ac_sb, group);
if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) // Unreachable
goto out;
After commit 9008a58e5d ("ext4: make the bitmap read routines return
real error codes") merged, Commit 163a203ddb ("ext4: mark block group
as corrupt on block bitmap error") is no real solution for allocating
blocks from corrupted block groups. This is because if
'EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)' is true, then
'ext4_mb_load_buddy()' may return an error. This means that the block
allocation will fail.
Therefore, check block group if corrupted when ext4_mb_load_buddy()
returns error.
Fixes: 163a203ddb ("ext4: mark block group as corrupt on block bitmap error")
Fixes: 9008a58e5d ("ext4: make the bitmap read routines return real error codes")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260302134619.3145520-1-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
commit 82f80e2e3b ("ext4: add extent status cache support to kunit tests"),
added ext4_es_register_shrinker() in extents_kunit_init() function but
failed to add the unregister shrinker routine in extents_kunit_exit().
This could cause the following percpu_counters list corruption bug.
ok 1 split unwrit extent to 2 extents and convert 1st half writ
slab kmalloc-4k start c0000002007ff000 pointer offset 1448 size 4096
list_add corruption. next->prev should be prev (c000000004bc9e60), but was 0000000000000000. (next=c0000002007ff5a8).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:29!
cpu 0x2: Vector: 700 (Program Check) at [c000000241927a30]
pc: c000000000f26ed0: __list_add_valid_or_report+0x120/0x164
lr: c000000000f26ecc: __list_add_valid_or_report+0x11c/0x164
sp: c000000241927cd0
msr: 800000000282b033
current = 0xc000000241215200
paca = 0xc0000003fffff300 irqmask: 0x03 irq_happened: 0x09
pid = 258, comm = kunit_try_catch
kernel BUG at lib/list_debug.c:29!
enter ? for help
__percpu_counter_init_many+0x148/0x184
ext4_es_register_shrinker+0x74/0x23c
extents_kunit_init+0x100/0x308
kunit_try_run_case+0x78/0x1f8
kunit_generic_run_threadfn_adapter+0x40/0x70
kthread+0x190/0x1a0
start_kernel_thread+0x14/0x18
2:mon>
This happens because:
extents_kunit_init(test N):
ext4_es_register_shrinker(sbi)
percpu_counters_init() x 4; // this adds 4 list nodes to global percpu_counters list
list_add(&fbc->list, &percpu_counters);
shrinker_register();
extents_kunit_exit(test N):
kfree(sbi); // frees sbi w/o removing those 4 list nodes.
// So, those list node now becomes dangling pointers
extents_kunit_init(test N+1):
kzalloc_obj(ext4_sb_info) // allocator returns same page, but zeroed.
ext4_es_register_shrinker(sbi)
percpu_counters_init()
list_add(&fbc->list, &percpu_counters);
__list_add_valid(new, prev, next);
next->prev != prev // list corruption bug detected, since next->prev = NULL
Fixes: 82f80e2e3b ("ext4: add extent status cache support to kunit tests")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/5bb9041471dab8ce870c191c19cbe4df57473be8.1772381213.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Replace BUG_ON() with proper error handling when inline data size
exceeds PAGE_SIZE. This prevents kernel panic and allows the system to
continue running while properly reporting the filesystem corruption.
The error is logged via ext4_error_inode(), the buffer head is released
to prevent memory leak, and -EFSCORRUPTED is returned to indicate
filesystem corruption.
Signed-off-by: Yuto Ohnuki <ytohnuki@amazon.com>
Link: https://patch.msgid.link/20260223123345.14838-2-ytohnuki@amazon.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
