Pull misc core fixes from Ingo Molnar: - Fix an MM-CID race that can cause an OOB write (Rik van Riel) - Fix a debugobjects OOM handling race (Thomas Gleixner) * tag 'core-urgent-2026-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debugobjects: Plug race against a concurrent OOM disable sched/mmcid: Fix OOB clear_bit when CID is MM_CID_UNSET in fixup path
Pull more MM updates from Andrew Morton: - "khugepaged: add mTHP collapse support" (Nico Pache) Provide khugepaged with the capability to collapse anonymous memory regions to mTHPs - "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable files" (Zi Yan) Remove the READ_ONLY_THP_FOR_FS check in file_thp_enabled(), so that khugepaged and MADV_COLLAPSE can run on filesystems with PMD THP pagecache support even without READ_ONLY_THP_FOR_FS enabled - "make MM selftests more CI friendly" (Mike Rapoport) General fixes and cleanups to the MM selftests. Also move more MM selftests under the kselftest framework, making them more amenable to ongoing CI testing - "selftests/mm: fix failures and robustness improvements" and "selftests/mm: assorted fixes for hmm-tests" (Sayali Patil) Fix several issues in MM selftests which were revealed by powerpc 64k pagesize * tag 'mm-stable-2026-06-23-08-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (118 commits) Revert "mm: limit filemap_fault readahead to VMA boundaries" mm/vmscan: pass NULL to trace vmscan node reclaim mm: use mapping_mapped to simplify the code selftests/mm: fix exclusive_cow test fork() handling selftests/mm: remove hardcoded THP sizing assumptions in hmm tests selftests/mm: allow PUD-level entries in compound testcase of hmm tests mm/gup_test: reject wrapped user ranges mm/page_frag: reject invalid CPUs in page_frag_test mm/damon/core: always put unsuccessfully committed target pids mm: page_isolation: avoid unsafe folio reads while scanning compound pages mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show() selftests: mm: fix and speedup "droppable" test mm: merge writeout into pageout MAINTAINERS: add Hao Ge as reviewer for codetag and alloc_tag selftests/mm: clarify alternate unmapping in compaction_test selftests/mm: move hwpoison setup into run_test() and silence modprobe output for memory-failure category selftests/mm: skip uffd-stress test when nr_pages_per_cpu is zero selftests/mm: skip uffd-wp-mremap if UFFD write-protect is unsupported selftests/mm: ensure destination is hugetlb-backed in hugetlb-mremap selftest/mm: register existing mapping with userfaultfd in hugetlb-mremap ...
syzbot reported a puzzling splat:
WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20
stub_timer() is installed as timer callback function in
hrtimer_fixup_assert_init(), which is invoked when
debug_object_assert_init() can't find a shadow object. In that case debug
objects emits a warning about it before invoking the fixup.
Though the provided console log lacks this warning and instead has the
following a few seconds before the splat:
ODEBUG: Out of memory. ODEBUG disabled
So the object was looked up in debug_object_assert_init() and the lookup
failed due a concurrent out of memory situation which disabled debug
objects and freed the shadow objects:
debug_object_assert_init()
if (!debug_objects_enabled)
return; obj = alloc();
if (!obj) {
// Out of memory
debug_objects_enabled = false;
free_objects();
obj = lookup_or_alloc();
// The lookup failed because the other side
// removed the objects, so this returns
// an error code as the object in question
// is not statically initialized
if (!IS_ERR_OR_NULL(obj))
return;
if (!obj) {
debug_oom();
return;
}
print(...)
if (!debug_objects_enabled)
return;
fixup(...)
The debug object splat is skipped because debug_objects_enabled is false,
but the fixup callback is invoked unconditionally, which makes the timer
disfunctional.
This is only a problem in debug_object_assert_init() and
debug_object_activate() as both have to handle statically initialized
objects and therefore must handle the error pointer return case
gracefully. All other places only handle the found/not found case and the
NULL pointer return is a signal for OOM. Otherwise they get a valid shadow
object.
Plug the hole by checking whether debug objects are still enabled before
invoking the print and fixup function in those two places.
Fixes: b84d435cc228 ("debugobjects: Extend to assert that an object is initialized")
Reported-by: syzbot+5e8dda76ca21dae314b6@syzkaller.appspotmail.com
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/874iiwlzlb.ffs@fw13
I keep having to do this, because people think they can just move
directories around and move the gitignore files around with them.
You really can't do that - the old generated files stay around for
others, and still need to be ignored in the old location.
So when moving gitignore entries around because you moved the files (or
when moving a whole gitignore file around because the directory it was
in moved), the old gitignore situation needs to be dealt with.
Yes, those files may have moved in *your* tree when you moved the
directory. And yes, new repositories will never even have seen them.
But all those other developers that see the result of your move still
likely have a working tree with the old state, and the files that were
hidden from git by an old gitignore file do not suddenly become
relevant.
Fixes: 3626738bc714 ("raid6: move to lib/raid/")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull non-MM updates from Andrew Morton:
- "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)
Fix a taskstats TGID aggregation bug where fields added in the TGID
query path were not preserved after thread exit, and adds a kselftest
covering the regression.
- "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)
Improve lib/tests/string_helpers_kunit.c a little
- "lib/base64: decode fixes" (Josh Law)
Address minor issues in lib/base64.c
- "selftests/filelock: Make output more kselftestish" (Mark Brown)
Make the output from the ofdlocks test a bit easier for tooling to
work with. Also ignore the generated file
- "uaccess: unify inline vs outline copy_{from,to}_user() selection"
(Yury Norov)
Simplify the usercopy code by removing the selectability of inlining
copy_{from,to}_user().
- "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)
Fix a number of possible issues in the ocfs2 xattr code
- "lib and lib/cmdline enhancements" (Dmitry Antipov)
Provide additional robustness checking in the cmdline handling code
and its in-kernel testing and selftests
- "cleanup the RAID6 P/Q library" (Christoph Hellwig)
Clean up the RAID6 P/Q library to match the recent updates to the
RAID 5 XOR library and other CRC/crypto libraries
- "ocfs2: harden inode validators against forged metadata" (Michael
Bommarito)
Add three structural checks to OCFS2 dinode validation so malformed
on-disk fields are rejected before ocfs2_populate_inode() copies them
into the in-core inode
- "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
Rapoport)
Clean up the lib/raid code by using kmalloc() in more places
* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
lib: interval_tree_test: validate benchmark parameters
ocfs2: avoid moving extents to occupied clusters
treewide: fix transposed "sign" typos and update spelling.txt
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
fat: reject BPB volumes whose data area starts beyond total sectors
selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
lib/test_firmware: allocate the configured into_buf size
fs: efs: remove unneeded debug prints
checkpatch: cuppress warnings when Reported-by: is followed by Link:
MAINTAINERS: add Alexander as a kcov reviewer
mailmap: update Alexander Sverdlin's Email addresses
fs: fat: inode: replace sprintf() with scnprintf()
ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
ocfs2/dlm: require a ref for locking_state debugfs open
ocfs2: reject FITRIM ranges shorter than a cluster
ocfs2: validate fast symlink target during inode read
ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
...
Letting a function argument indicate whether a lock or unlock operation
should be performed is incompatible with compile-time analysis of locking
operations by sparse and Clang. Hence, split codetag_lock_module_list()
into two functions: a function that locks cttype->mod_lock and another
function that unlocks cttype->mod_lock. No functionality has been
changed. See also commit 916cc5167cc6 ("lib: code tagging framework").
Link: https://lore.kernel.org/20260324214226.3684605-1-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
allocinfo_start() only reinitializes the codetag iterator at position 0.
For subsequent reads (position > 0), it reuses cached iterator state from
the previous batch. allocinfo_stop() drops mod_lock between read batches,
which allows module unload to complete and free the module memory that the
cached iterator still references:
CPU0 (read) CPU1 (rmmod)
---- ----
allocinfo_start(pos=0)
down_read(mod_lock)
allocinfo_show()
...
allocinfo_stop()
up_read(mod_lock)
codetag_unload_module()
kfree(cmod)
release_module_tags()
...
free_mod_mem()
allocinfo_start(pos=N)
down_read(mod_lock)
// reuses cached iter, skips re-init
allocinfo_show()
ct->filename <-- UAF
After free_mod_mem() frees the module's .rodata, allocinfo_show()
dereferences ct->filename, ct->function which point there.
Save the iterator state in allocinfo_next() and resume from it in
allocinfo_start() with codetag_next_ct(), which detects module removal via
idr_find() returning NULL and skips to the next module.
Link: https://lore.kernel.org/20260604065938.105991-1-hao.ge@linux.dev
Fixes: 9f44df50fee4 ("alloc_tag: keep codetag iterator active between read()")
Signed-off-by: Hao Ge <hao.ge@linux.dev>
Suggested-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pages allocated before page_ext is available have their codetag left uninitialized. Track these early PFNs and clear their codetag in clear_early_alloc_pfn_tag_refs() to avoid "alloc_tag was not set" warnings when they are freed later. Currently a fixed-size array of 8192 entries is used, with a warning if the limit is exceeded. However, the number of early allocations depends on the number of CPUs and can be larger than 8192. Replace the fixed-size array with a dynamically allocated linked list of pfn_pool structs. Each node is allocated via alloc_page() and mapped to a pfn_pool containing a next pointer, an atomic slot counter, and a PFN array that fills the remainder of the page. The tracking pages themselves are allocated via alloc_page(), which would trigger __pgalloc_tag_add() -> alloc_tag_add_early_pfn() and recurse indefinitely. Introduce __GFP_NO_CODETAG (reuses the %__GFP_NO_OBJ_EXT bit) and pass gfp_flags through pgalloc_tag_add() so that the early path can skip recording allocations that carry this flag. Link: https://lore.kernel.org/20260604024008.46592-1-hao.ge@linux.dev Signed-off-by: Hao Ge <hao.ge@linux.dev> Suggested-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull liveupdate updates from Mike Rapoport:
"Kexec Handover (KHO):
- make memory preservation compatible with deferred initialization
of the memory map
Live Update Orchestrator (LUO):
- add LIVEUPDATE_SESSION_GET_NAME ioctl and parameter verification
for LIVEUPDATE_IOCTL_CREATE_SESSION ioctl
- documentation updates for liveupdate=on command line option,
systemd support and the current compatibility status
- remove the fixed limits on the number of files that can be
preserved within a single session, and the total number of
sessions managed by the LUO
Misc fixes:
- reference count incoming File-Lifecycle-Bound (FLB) data so
it cannot be freed while a subsystem is still using it
- fixes for a TOCTOU race in luo_session_retrieve(), a use-
after-free in the file finish and unpreserve paths, concurrent
session mutations during reboot and serialization on
preserve_context kexec
- make sure ioctls for incoming LUO sessions are blocked for
outgoing sessions and vice versa
- make sure KHO scratch size is always aligned by
CMA_MIN_ALIGNMENT_BYTES
- fix memblock tests build issue introduced by KHO changes"
* tag 'liveupdate-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (36 commits)
liveupdate: Document that retrieve failure is permanent
docs: memfd_preservation: fix rendering of ABI documentation
selftests/liveupdate: Add stress-files kexec test
selftests/liveupdate: Add stress-sessions kexec test
selftests/liveupdate: Test session and file limit removal
liveupdate: Remove limit on the number of files per session
liveupdate: Remove limit on the number of sessions
liveupdate: defer session block allocation and physical address setting
kho: add support for linked-block serialization
liveupdate: Extract luo_session_deserialize_one helper
liveupdate: Extract luo_file_deserialize_one helper
liveupdate: register luo_ser as KHO subtree
liveupdate: centralize state management into struct luo_ser
liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fd
liveupdate: change file_set->count type to u64 for type safety
liveupdate: Remove unused ser field from struct luo_session
liveupdate: fix u-a-f in luo_file_unpreserve_files() and luo_file_finish()
liveupdate: block session mutations during reboot
liveupdate: fix TOCTOU race in luo_session_retrieve()
liveupdate: skip serialization for context-preserving kexec
...
Pull strncpy removal from Kees Cook:
- Remove the per-arch strncpy implementations in alpha, m68k, powerpc,
x86, and xtensa
- Remove strncpy API
Over the last 6 years working on strncpy removal there were 362
commits by 70 contributors. Folks with more than 1 commit were:
211 Justin Stitt <justinstitt@google.com>
22 Xu Panda <xu.panda@zte.com.cn>
21 Kees Cook <kees@kernel.org>
17 Thorsten Blum <thorsten.blum@linux.dev>
12 Arnd Bergmann <arnd@arndb.de>
4 Pranav Tyagi <pranav.tyagi03@gmail.com>
4 Lee Jones <lee@kernel.org>
2 Steven Rostedt <rostedt@goodmis.org>
2 Sam Ravnborg <sam@ravnborg.org>
2 Marcelo Moreira <marcelomoreira1905@gmail.com>
2 Krzysztof Kozlowski <krzk@kernel.org>
2 Kalle Valo <kvalo@kernel.org>
2 Jaroslav Kysela <perex@perex.cz>
2 Daniel Thompson <danielt@kernel.org>
2 Andrew Lunn <andrew@lunn.ch>
* tag 'strncpy-removal-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
string: Remove strncpy() from the kernel
xtensa: Remove arch-specific strncpy() implementation
x86: Remove arch-specific strncpy() implementation
powerpc: Remove arch-specific strncpy() implementation
m68k: Remove arch-specific strncpy() implementation
alpha: Remove arch-specific strncpy() implementation