user/sven/linux.git/kernel/fork.c, branch v6.17.3

futex: Use correct exit on failure from futex_hash_allocate_default()

2025-09-24T07:20:02Z

copy_process() uses the wrong error exit path from futex_hash_allocate_default(). After exiting from futex_hash_allocate_default(), neither tasklist_lock nor siglock has been acquired. The exit label bad_fork_core_free unlocks both of these locks which is wrong. The next exit label, bad_fork_cancel_cgroup, is the correct exit. sched_cgroup_fork() did not allocate any resources that need to freed. Use bad_fork_cancel_cgroup on error exit from futex_hash_allocate_default(). Fixes: 7c4f75a21f636 ("futex: Allow automatic allocation of process wide futex hash") Reported-by: syzbot+80cb3cc5c14fad191a10@syzkaller.appspotmail.com Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (Google) Closes: https://lore.kernel.org/all/68cb1cbd.050a0220.2ff435.0599.GAE@google.com

futex: Move futex_hash_free() back to __mmput()

2025-08-31T09:48:19Z

To avoid a memory leak via mm_alloc() + mmdrop() the futex cleanup code has been moved to __mmdrop(). This resulted in a warnings if the futex hash table has been allocated via vmalloc() the mmdrop() was invoked from atomic context. The free path must stay in __mmput() to ensure it is invoked from preemptible context. In order to avoid the memory leak, delay the allocation of mm_struct::mm->futex_ref to futex_hash_allocate(). This works because neither the per-CPU counter nor the private hash has been allocated and therefore - futex_private_hash() callers (such as exit_pi_state_list()) don't acquire reference if there is no private hash yet. There is also no reference put. - Regular callers (futex_hash()) fallback to global hash. No reference counting here. The futex_ref member can be allocated in futex_hash_allocate() before the private hash itself is allocated. This happens either while the first thread is created or on request. In both cases the process has just a single thread so there can be either futex operation in progress or the request to create a private hash. Move futex_hash_free() back to __mmput(); Move the allocation of mm_struct::futex_ref to futex_hash_allocate(). [ bp: Fold a follow-up fix to prevent a use-after-free: https://lore.kernel.org/r/20250830213806.sEKuuGSm@linutronix.de ] Fixes: e703b7e247503 ("futex: Move futex cleanup to __mmdrop()") Closes: https://lore.kernel.org/all/20250821102721.6deae493@kernel.org/ Reported-by: Jakub Kicinski Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Link: https://lkml.kernel.org/r/20250822141238.PfnkTjFb@linutronix.de

Merge tag 'locking_urgent_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-08-10T05:11:39Z

Pull locking fix from Borislav Petkov: - Prevent a futex hash leak due to different mm lifetimes * tag 'locking_urgent_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Move futex cleanup to __mmdrop()

Merge tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-05T13:02:07Z

Pull more MM updates from Andrew Morton: "Significant patch series in this pull request: - "mseal cleanups" (Lorenzo Stoakes) Some mseal cleaning with no intended functional change. - "Optimizations for khugepaged" (David Hildenbrand) Improve khugepaged throughput by batching PTE operations for large folios. This gain is mainly for arm64. - "x86: enable EXECMEM_ROX_CACHE for ftrace and kprobes" (Mike Rapoport) A bugfix, additional debug code and cleanups to the execmem code. - "mm/shmem, swap: bugfix and improvement of mTHP swap in" (Kairui Song) Bugfixes, cleanups and performance improvememnts to the mTHP swapin code" * tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (38 commits) mm: mempool: fix crash in mempool_free() for zero-minimum pools mm: correct type for vmalloc vm_flags fields mm/shmem, swap: fix major fault counting mm/shmem, swap: rework swap entry and index calculation for large swapin mm/shmem, swap: simplify swapin path and result handling mm/shmem, swap: never use swap cache and readahead for SWP_SYNCHRONOUS_IO mm/shmem, swap: tidy up swap entry splitting mm/shmem, swap: tidy up THP swapin checks mm/shmem, swap: avoid redundant Xarray lookup during swapin x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations execmem: drop writable parameter from execmem_fill_trapping_insns() execmem: add fallback for failures in vmalloc(VM_ALLOW_HUGE_VMAP) execmem: move execmem_force_rw() and execmem_restore_rox() before use execmem: rework execmem_cache_free() execmem: introduce execmem_alloc_rw() execmem: drop unused execmem_update_copy() mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped mm/rmap: add anon_vma lifetime debug check mm: remove mm/io-mapping.c ...

Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-03T23:23:09Z

Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...

mm: add process info to bad rss-counter warning

2025-08-02T19:06:08Z

Enhance the debugging information in check_mm() by including the process name and PID when reporting bad rss-counter states. This helps identify which process is associated with the memory accounting issue. Link: https://lkml.kernel.org/r/20250723100901.1909683-1-liuqiye2025@163.com Signed-off-by: Xuanye Liu Acked-by: SeongJae Park Cc: Ben Segall Cc: David Hildenbrand Cc: Dietmar Eggemann Cc: Ingo Molnar Cc: Juri Lelli Cc: Kees Cook Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mel Gorman Cc: Michal Hocko Cc: Mike Rapoport Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Valentin Schneider Cc: Vincent Guittot Cc: Vlastimil Babka Signed-off-by: Andrew Morton

futex: Move futex cleanup to __mmdrop()

2025-08-02T13:11:52Z

Futex hash allocations are done in mm_init() and the cleanup happens in __mmput(). That works most of the time, but there are mm instances which are instantiated via mm_alloc() and freed via mmdrop(), which causes the futex hash to be leaked. Move the cleanup to __mmdrop(). Fixes: 56180dd20c19 ("futex: Use RCU-based per-CPU reference counting instead of rcuref_t") Reported-by: André Draszik Signed-off-by: Thomas Gleixner Tested-by: André Draszik Link: https://lore.kernel.org/all/87ldo5ihu0.ffs@tglx Closes: https://lore.kernel.org/all/0c8cc83bb73abf080faf584f319008b67d0931db.camel@linaro.org

Merge tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-08-01T16:46:24Z

Pull initial deferred unwind infrastructure from Steven Rostedt: "This is the core infrastructure for the deferred unwinder that is required for sframes[1]. Several other patch series are based on this work although those patch series are not dependent on each other. In order to simplify the development, having this core series upstream will allow the other series to be worked on in parallel. The other series are: - The two patches to implement x86 support [2] [3] - The s390 work [4] - The perf work [5] - The ftrace work [6] - The sframe work [7] And more is on the way. The core infrastructure adds the following in kernel APIs: - int unwind_user_faultable(struct unwind_stacktrace *trace); Performs a user space stack trace that may fault user pages in. - int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func); Allows a tracer to register with the unwind deferred infrastructure. - int unwind_deferred_request(struct unwind_work *work, u64 *cookie); Used when a tracer request a deferred trace. Can be called from interrupt or NMI context. - void unwind_deferred_cancel(struct unwind_work *work); Called by a tracer to unregister from the deferred unwind infrastructure. - void unwind_deferred_task_exit(struct task_struct *task); Called by task exit code to flush any pending unwind requests. - void unwind_task_init(struct task_struct *task); Called by do_fork() to initialize the task struct for the deferred unwinder. - void unwind_task_free(struct task_struct *task); Called by do_exit() to free up any resources used by the deferred unwinder. None of the above is actually compiled unless an architecture enables it, which none currently do" Link: https://sourceware.org/binutils/wiki/sframe [1] Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.260781923@kernel.org/ [2] Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.432327787@kernel.org/ [3] Link: https://lore.kernel.org/linux-trace-kernel/20250710163522.3195293-1-jremus@linux.ibm.com/ [4] Link: https://lore.kernel.org/linux-trace-kernel/20250718164119.089692174@kernel.org/ [5] Link: https://lore.kernel.org/linux-trace-kernel/20250424192612.505622711@goodmis.org/ [6] Link: https://lore.kernel.org/linux-trace-kernel/20250717012848.927473176@kernel.org/ [7] * tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: unwind: Finish up unwind when a task exits unwind deferred: Use SRCU unwind_deferred_task_work() unwind: Add USED bit to only have one conditional on way back to user space unwind deferred: Add unwind_completed mask to stop spurious callbacks unwind deferred: Use bitmask to determine which callbacks to call unwind_user/deferred: Make unwind deferral requests NMI-safe unwind_user/deferred: Add deferred unwinding interface unwind_user/deferred: Add unwind cache unwind_user/deferred: Add unwind_user_faultable() unwind_user: Add user space unwinding API with frame pointer support

Merge tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-07-30T23:23:12Z

Pull runtime verification updates from Steven Rostedt: - Added Linear temporal logic monitors for RT application Real-time applications may have design flaws causing them to have unexpected latency. For example, the applications may raise page faults, or may be blocked trying to take a mutex without priority inheritance. However, while attempting to implement DA monitors for these real-time rules, deterministic automaton is found to be inappropriate as the specification language. The automaton is complicated, hard to understand, and error-prone. For these cases, linear temporal logic is found to be more suitable. The LTL is more concise and intuitive. - Make printk_deferred() public The new monitors needed access to printk_deferred(). Make them visible for the entire kernel. - Add a vpanic() to allow for va_list to be passed to panic. - Add rtapp container monitor. A collection of monitors that check for common problems with real-time applications that cause unexpected latency. - Add page fault tracepoints to risc-v These tracepoints are necessary to for the RV monitor to run on risc-v. - Fix the behaviour of the rv tool with -s and idle tasks. - Allow the rv tool to gracefully terminate with SIGTERM - Adjusts dot2c not to create lines over 100 columns - Properly order nested monitors in the RV Kconfig file - Return the registration error in all DA monitor instead of 0 - Update and add new sched collection monitors Replace tss and sncid monitors with more complete sts: Not only prove that switches occur in scheduling context and scheduling needs interrupt disabled but also that each call to the scheduler disables interrupts to (optionally) switch. New monitor: nrp Preemption requires need resched which is cleared by any switch (includes a non optimal workaround for /nested/ preemptions) New monitor: sssw suspension requires setting the task to sleepable and, after the switch occurs, the task requires a wakeup to come back to runnable New monitor: opid waking and need-resched operations occur with interrupts and preemption disabled or in IRQ without explicitly disabling preemption" * tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits) rv: Add opid per-cpu monitor rv: Add nrp and sssw per-task monitors rv: Replace tss and sncid monitors with more complete sts sched: Adapt sched tracepoints for RV task model rv: Retry when da monitor detects race conditions rv: Adjust monitor dependencies rv: Use strings in da monitors tracepoints rv: Remove trailing whitespace from tracepoint string rv: Add da_handle_start_run_event_ to per-task monitors rv: Fix wrong type cast in reactors_show() and monitor_reactor_show() rv: Fix wrong type cast in monitors_show() rv: Remove struct rv_monitor::reacting rv: Remove rv_reactor's reference counter rv: Merge struct rv_reactor_def into struct rv_reactor rv: Merge struct rv_monitor_def into struct rv_monitor rv: Remove unused field in struct rv_monitor_def rv: Return init error when registering monitors verification/rvgen: Organise Kconfig entries for nested monitors tools/dot2c: Fix generated files going over 100 column limit tools/rv: Stop gracefully also on SIGTERM ...

Merge tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

2025-07-30T04:43:08Z

Pull sysctl updates from Joel Granados: - Move sysctls out of the kern_table array This is the final move of ctl_tables into their respective subsystems. Only 5 (out of the original 50) will remain in kernel/sysctl.c file; these handle either sysctl or common arch variables. By decentralizing sysctl registrations, subsystem maintainers regain control over their sysctl interfaces, improving maintainability and reducing the likelihood of merge conflicts. - docs: Remove false positives from check-sysctl-docs Stopped falsely identifying sysctls as undocumented or unimplemented in the check-sysctl-docs script. This script can now be used to automatically identify if documentation is missing. * tag 'sysctl-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (23 commits) docs: Downgrade arm64 & riscv from titles to comment docs: Replace spaces with tabs in check-sysctl-docs docs: Remove colon from ctltable title in vm.rst docs: Add awk section for ucount sysctl entries docs: Use skiplist when checking sysctl admin-guide docs: nixify check-sysctl-docs sysctl: rename kern_table -> sysctl_subsys_table kernel/sys.c: Move overflow{uid,gid} sysctl into kernel/sys.c uevent: mv uevent_helper into kobject_uevent.c sysctl: Removed unused variable sysctl: Nixify sysctl.sh sysctl: Remove superfluous includes from kernel/sysctl.c sysctl: Remove (very) old file changelog sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.c sysctl: move cad_pid into kernel/pid.c sysctl: Move tainted ctl_table into kernel/panic.c Input: sysrq: mv sysrq into drivers/tty/sysrq.c fork: mv threads-max into kernel/fork.c parisc/power: Move soft-power into power.c mm: move randomize_va_space into memory.c ...