user/sven/linux.git/kernel, branch v5.10.243

cpufreq/sched: Explicitly synchronize limits_changed flag handling

2025-09-09T16:45:22Z

[ Upstream commit 79443a7e9da3c9f68290a8653837e23aba0fa89f ] The handling of the limits_changed flag in struct sugov_policy needs to be explicitly synchronized to ensure that cpufreq policy limits updates will not be missed in some cases. Without that synchronization it is theoretically possible that the limits_changed update in sugov_should_update_freq() will be reordered with respect to the reads of the policy limits in cpufreq_driver_resolve_freq() and in that case, if the limits_changed update in sugov_limits() clobbers the one in sugov_should_update_freq(), the new policy limits may not take effect for a long time. Likewise, the limits_changed update in sugov_limits() may theoretically get reordered with respect to the updates of the policy limits in cpufreq_set_policy() and if sugov_should_update_freq() runs between them, the policy limits change may be missed. To ensure that the above situations will not take place, add memory barriers preventing the reordering in question from taking place and add READ_ONCE() and WRITE_ONCE() annotations around all of the limits_changed flag updates to prevent the compiler from messing up with that code. Fixes: 600f5badb78c ("cpufreq: schedutil: Don't skip freq update when limits change") Cc: 5.3+ # 5.3+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Christian Loehle Link: https://patch.msgid.link/3376719.44csPzL39Z@rjwysocki.net [ Adjust context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

dma/pool: Ensure DMA_DIRECT_REMAP allocations are decrypted

2025-09-04T12:41:44Z

commit 89a2d212bdb4bc29bed8e7077abe054b801137ea upstream. When CONFIG_DMA_DIRECT_REMAP is enabled, atomic pool pages are remapped via dma_common_contiguous_remap() using the supplied pgprot. Currently, the mapping uses pgprot_dmacoherent(PAGE_KERNEL), which leaves the memory encrypted on systems with memory encryption enabled (e.g., ARM CCA Realms). This can cause the DMA layer to fail or crash when accessing the memory, as the underlying physical pages are not configured as expected. Fix this by requesting a decrypted mapping in the vmap() call: pgprot_decrypted(pgprot_dmacoherent(PAGE_KERNEL)) This ensures that atomic pool memory is consistently mapped unencrypted. Cc: stable@vger.kernel.org Signed-off-by: Shanker Donthineni Reviewed-by: Catalin Marinas Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20250811181759.998805-1-sdonthineni@nvidia.com Signed-off-by: Greg Kroah-Hartman

ftrace: Fix potential warning in trace_printk_seq during ftrace_dump

2025-09-04T12:41:41Z

[ Upstream commit 4013aef2ced9b756a410f50d12df9ebe6a883e4a ] When calling ftrace_dump_one() concurrently with reading trace_pipe, a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race condition. The issue occurs because: CPU0 (ftrace_dump) CPU1 (reader) echo z > /proc/sysrq-trigger !trace_empty(&iter) trace_iterator_reset(&iter) <- len = size = 0 cat /sys/kernel/tracing/trace_pipe trace_find_next_entry_inc(&iter) __find_next_entry ring_buffer_empty_cpu <- all empty return NULL trace_printk_seq(&iter.seq) WARN_ON_ONCE(s->seq.len >= s->seq.size) In the context between trace_empty() and trace_find_next_entry_inc() during ftrace_dump, the ring buffer data was consumed by other readers. This caused trace_find_next_entry_inc to return NULL, failing to populate `iter.seq`. At this point, due to the prior trace_iterator_reset, both `iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal, the WARN_ON_ONCE condition is triggered. Move the trace_printk_seq() into the if block that checks to make sure the return value of trace_find_next_entry_inc() is non-NULL in ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before subsequent operations. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Ingo Molnar Link: https://lore.kernel.org/20250822033343.3000289-1-wutengda@huaweicloud.com Fixes: d769041f8653 ("ring_buffer: implement new locking") Signed-off-by: Tengda Wu Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key

2025-08-28T14:22:58Z

[ Upstream commit 65f97cc81b0adc5f49cf6cff5d874be0058e3f41 ] The following lockdep splat was observed. [ 812.359086] ============================================ [ 812.359089] WARNING: possible recursive locking detected [ 812.359097] -------------------------------------------- [ 812.359100] runtest.sh/30042 is trying to acquire lock: [ 812.359105] ffffffffa7f27420 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0xe/0x20 [ 812.359131] [ 812.359131] but task is already holding lock: [ 812.359134] ffffffffa7f27420 (cpu_hotplug_lock){++++}-{0:0}, at: cpuset_write_resmask+0x98/0xa70 : [ 812.359267] Call Trace: [ 812.359272] [ 812.359367] cpus_read_lock+0x3c/0xe0 [ 812.359382] static_key_enable+0xe/0x20 [ 812.359389] check_insane_mems_config.part.0+0x11/0x30 [ 812.359398] cpuset_write_resmask+0x9f2/0xa70 [ 812.359411] cgroup_file_write+0x1c7/0x660 [ 812.359467] kernfs_fop_write_iter+0x358/0x530 [ 812.359479] vfs_write+0xabe/0x1250 [ 812.359529] ksys_write+0xf9/0x1d0 [ 812.359558] do_syscall_64+0x5f/0xe0 Since commit d74b27d63a8b ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock order"), the ordering of cpu hotplug lock and cpuset_mutex had been reversed. That patch correctly used the cpuslocked version of the static branch API to enable cpusets_pre_enable_key and cpusets_enabled_key, but it didn't do the same for cpusets_insane_config_key. The cpusets_insane_config_key can be enabled in the check_insane_mems_config() which is called from update_nodemask() or cpuset_hotplug_update_tasks() with both cpu hotplug lock and cpuset_mutex held. Deadlock can happen with a pending hotplug event that tries to acquire the cpu hotplug write lock which will block further cpus_read_lock() attempt from check_insane_mems_config(). Fix that by switching to use static_branch_enable_cpuslocked(). Fixes: d74b27d63a8b ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock order") Signed-off-by: Waiman Long Reviewed-by: Juri Lelli Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

mm/page_alloc: detect allocation forbidden by cpuset and bail out early

2025-08-28T14:22:58Z

[ Upstream commit 8ca1b5a49885f0c0c486544da46a9e0ac790831d ] There was a report that starting an Ubuntu in docker while using cpuset to bind it to movable nodes (a node only has movable zone, like a node for hotplug or a Persistent Memory node in normal usage) will fail due to memory allocation failure, and then OOM is involved and many other innocent processes got killed. It can be reproduced with command: $ docker run -it --rm --cpuset-mems 4 ubuntu:latest bash -c "grep Mems_allowed /proc/self/status" (where node 4 is a movable node) runc:[2:INIT] invoked oom-killer: gfp_mask=0x500cc2(GFP_HIGHUSER|__GFP_ACCOUNT), order=0, oom_score_adj=0 CPU: 8 PID: 8291 Comm: runc:[2:INIT] Tainted: G W I E 5.8.2-0.g71b519a-default #1 openSUSE Tumbleweed (unreleased) Hardware name: Dell Inc. PowerEdge R640/0PHYDR, BIOS 2.6.4 04/09/2020 Call Trace: dump_stack+0x6b/0x88 dump_header+0x4a/0x1e2 oom_kill_process.cold+0xb/0x10 out_of_memory.part.0+0xaf/0x230 out_of_memory+0x3d/0x80 __alloc_pages_slowpath.constprop.0+0x954/0xa20 __alloc_pages_nodemask+0x2d3/0x300 pipe_write+0x322/0x590 new_sync_write+0x196/0x1b0 vfs_write+0x1c3/0x1f0 ksys_write+0xa7/0xe0 do_syscall_64+0x52/0xd0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Mem-Info: active_anon:392832 inactive_anon:182 isolated_anon:0 active_file:68130 inactive_file:151527 isolated_file:0 unevictable:2701 dirty:0 writeback:7 slab_reclaimable:51418 slab_unreclaimable:116300 mapped:45825 shmem:735 pagetables:2540 bounce:0 free:159849484 free_pcp:73 free_cma:0 Node 4 active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB all_unreclaimable? no Node 4 Movable free:130021408kB min:9140kB low:139160kB high:269180kB reserved_highatomic:0KB active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:130023424kB managed:130023424kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:292kB local_pcp:84kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 0 Node 4 Movable: 1*4kB (M) 0*8kB 0*16kB 1*32kB (M) 0*64kB 0*128kB 1*256kB (M) 1*512kB (M) 1*1024kB (M) 0*2048kB 31743*4096kB (M) = 130021156kB oom-kill:constraint=CONSTRAINT_CPUSET,nodemask=(null),cpuset=docker-9976a269caec812c134fa317f27487ee36e1129beba7278a463dd53e5fb9997b.scope,mems_allowed=4,global_oom,task_memcg=/system.slice/containerd.service,task=containerd,pid=4100,uid=0 Out of memory: Killed process 4100 (containerd) total-vm:4077036kB, anon-rss:51184kB, file-rss:26016kB, shmem-rss:0kB, UID:0 pgtables:676kB oom_score_adj:0 oom_reaper: reaped process 8248 (docker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 2054 (node_exporter), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 1452 (systemd-journal), now anon-rss:0kB, file-rss:8564kB, shmem-rss:4kB oom_reaper: reaped process 2146 (munin-node), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 8291 (runc:[2:INIT]), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB The reason is that in this case, the target cpuset nodes only have movable zone, while the creation of an OS in docker sometimes needs to allocate memory in non-movable zones (dma/dma32/normal) like GFP_HIGHUSER, and the cpuset limit forbids the allocation, then out-of-memory killing is involved even when normal nodes and movable nodes both have many free memory. The OOM killer cannot help to resolve the situation as there is no usable memory for the request in the cpuset scope. The only reasonable measure to take is to fail the allocation right away and have the caller to deal with it. So add a check for cases like this in the slowpath of allocation, and bail out early returning NULL for the allocation. As page allocation is one of the hottest path in kernel, this check will hurt all users with sane cpuset configuration, add a static branch check and detect the abnormal config in cpuset memory binding setup so that the extra check cost in page allocation is not paid by everyone. [thanks to Micho Hocko and David Rientjes for suggesting not handling it inside OOM code, adding cpuset check, refining comments] Link: https://lkml.kernel.org/r/1632481657-68112-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang Suggested-by: Michal Hocko Acked-by: Michal Hocko Cc: David Rientjes Cc: Tejun Heo Cc: Zefan Li Cc: Johannes Weiner Cc: Mel Gorman Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Stable-dep-of: 65f97cc81b0a ("cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key") Signed-off-by: Sasha Levin

tracing: Limit access to parser->buffer when trace_get_user failed

2025-08-28T14:22:58Z

[ Upstream commit 6a909ea83f226803ea0e718f6e88613df9234d58 ] When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250813040232.1344527-1-pulehui@huaweicloud.com Fixes: 8c9af478c06b ("ftrace: Handle commands when closing set_ftrace_filter file") Signed-off-by: Pu Lehui Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tracing: Remove unneeded goto out logic

2025-08-28T14:22:58Z

[ Upstream commit c89504a703fb779052213add0e8ed642f4a4f1c8 ] Several places in the trace.c file there's a goto out where the out is simply a return. There's no reason to jump to the out label if it's not doing any more logic but simply returning from the function. Replace the goto outs with a return and remove the out labels. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Link: https://lore.kernel.org/20250801203857.538726745@kernel.org Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mm: drop the assumption that VM_SHARED always implies writable

2025-08-28T14:22:54Z

[ Upstream commit e8e17ee90eaf650c855adb0a3e5e965fd6692ff1 ] Patch series "permit write-sealed memfd read-only shared mappings", v4. The man page for fcntl() describing memfd file seals states the following about F_SEAL_WRITE:- Furthermore, trying to create new shared, writable memory-mappings via mmap(2) will also fail with EPERM. With emphasis on 'writable'. In turns out in fact that currently the kernel simply disallows all new shared memory mappings for a memfd with F_SEAL_WRITE applied, rendering this documentation inaccurate. This matters because users are therefore unable to obtain a shared mapping to a memfd after write sealing altogether, which limits their usefulness. This was reported in the discussion thread [1] originating from a bug report [2]. This is a product of both using the struct address_space->i_mmap_writable atomic counter to determine whether writing may be permitted, and the kernel adjusting this counter when any VM_SHARED mapping is performed and more generally implicitly assuming VM_SHARED implies writable. It seems sensible that we should only update this mapping if VM_MAYWRITE is specified, i.e. whether it is possible that this mapping could at any point be written to. If we do so then all we need to do to permit write seals to function as documented is to clear VM_MAYWRITE when mapping read-only. It turns out this functionality already exists for F_SEAL_FUTURE_WRITE - we can therefore simply adapt this logic to do the same for F_SEAL_WRITE. We then hit a chicken and egg situation in mmap_region() where the check for VM_MAYWRITE occurs before we are able to clear this flag. To work around this, perform this check after we invoke call_mmap(), with careful consideration of error paths. Thanks to Andy Lutomirski for the suggestion! [1]:https://lore.kernel.org/all/20230324133646.16101dfa666f253c4715d965@linux-foundation.org/ [2]:https://bugzilla.kernel.org/show_bug.cgi?id=217238 This patch (of 3): There is a general assumption that VMAs with the VM_SHARED flag set are writable. If the VM_MAYWRITE flag is not set, then this is simply not the case. Update those checks which affect the struct address_space->i_mmap_writable field to explicitly test for this by introducing [vma_]is_shared_maywrite() helper functions. This remains entirely conservative, as the lack of VM_MAYWRITE guarantees that the VMA cannot be written to. Link: https://lkml.kernel.org/r/cover.1697116581.git.lstoakes@gmail.com Link: https://lkml.kernel.org/r/d978aefefa83ec42d18dfa964ad180dbcde34795.1697116581.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes Suggested-by: Andy Lutomirski Reviewed-by: Jan Kara Cc: Alexander Viro Cc: Christian Brauner Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Mike Kravetz Cc: Muchun Song Signed-off-by: Andrew Morton Cc: stable@vger.kernel.org [isaacmanjarres: resolved merge conflicts due to due to refactoring that happened in upstream commit 5de195060b2e ("mm: resolve faulty mmap_region() error path behaviour")] Signed-off-by: Isaac J. Manjarres Signed-off-by: Greg Kroah-Hartman

tracing: Add down_write(trace_event_sem) when adding trace event

2025-08-28T14:22:53Z

[ Upstream commit b5e8acc14dcb314a9b61ff19dcd9fdd0d88f70df ] When a module is loaded, it adds trace events defined by the module. It may also need to modify the modules trace printk formats to replace enum names with their values. If two modules are loaded at the same time, the adding of the event to the ftrace_events list can corrupt the walking of the list in the code that is modifying the printk format strings and crash the kernel. The addition of the event should take the trace_event_sem for write while it adds the new event. Also add a lockdep_assert_held() on that semaphore in __trace_add_event_dirs() as it iterates the list. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/20250718223158.799bfc0c@batman.local.home Reported-by: Fusheng Huang(黄富生) Closes: https://lore.kernel.org/all/20250717105007.46ccd18f@batman.local.home/ Fixes: 110bf2b764eb6 ("tracing: add protection around module events unload") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ftrace: Also allocate and copy hash for reading of filter files

2025-08-28T14:22:52Z

commit bfb336cf97df7b37b2b2edec0f69773e06d11955 upstream. Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds the pointer to the global tracer hash to its iterator. Unlike the writer that allocates a copy of the hash, the reader keeps the pointer to the filter hashes. This is problematic because this pointer is static across function calls that release the locks that can update the global tracer hashes. This can cause UAF and similar bugs. Allocate and copy the hash for reading the filter files like it is done for the writers. This not only fixes UAF bugs, but also makes the code a bit simpler as it doesn't have to differentiate when to free the iterator's hash between writers and readers. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nathan Chancellor Cc: Linus Torvalds Link: https://lore.kernel.org/20250822183606.12962cc3@batman.local.home Fixes: c20489dad156 ("ftrace: Assign iter->hash to filter or notrace hashes on seq read") Closes: https://lore.kernel.org/all/20250813023044.2121943-1-wutengda@huaweicloud.com/ Closes: https://lore.kernel.org/all/20250822192437.GA458494@ax162/ Reported-by: Tengda Wu Tested-by: Tengda Wu Tested-by: Nathan Chancellor Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman