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3 daysbpf: Fix use-after-free in arena_vm_close on forkAlexei Starovoitov1-3/+16
commit 4fddde2a732de60bb97e3307d4eb69ac5f1d2b74 upstream. arena_vm_open() only bumps vml->mmap_count but never registers the child VMA in arena->vma_list. The vml->vma always points at the parent VMA, so after parent munmap the pointer dangles. If the child then calls bpf_arena_free_pages(), zap_pages() reads the stale vml->vma triggering use-after-free. Fix this by preventing the arena VMA from being inherited across fork with VM_DONTCOPY, and preventing VMA splits via the may_split callback. Also reject mremap with a .mremap callback returning -EINVAL. A same-size mremap(MREMAP_FIXED) on the full arena VMA reaches copy_vma() through the following path: check_prep_vma() - returns 0 early: new_len == old_len skips VM_DONTEXPAND check prep_move_vma() - vm_start == old_addr and vm_end == old_addr + old_len so may_split is never called move_vma() copy_vma_and_data() copy_vma() vm_area_dup() - copies vm_private_data (vml pointer) vm_ops->open() - bumps vml->mmap_count vm_ops->mremap() - returns -EINVAL, rollback unmaps new VMA The refcount ensures the rollback's arena_vm_close does not free the vml shared with the original VMA. Reported-by: Weiming Shi <bestswngs@gmail.com> Reported-by: Xiang Mei <xmei5@asu.edu> Fixes: 317460317a02 ("bpf: Introduce bpf_arena.") Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Link: https://lore.kernel.org/r/20260413194245.21449-1-alexei.starovoitov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 dayssched_ext: idle: Recheck prev_cpu after narrowing allowed maskDavid Carlier1-6/+6
commit b34c82777a2c0648ee053595f4b290fd5249b093 upstream. scx_select_cpu_dfl() narrows @allowed to @cpus_allowed & @p->cpus_ptr when the BPF caller supplies a @cpus_allowed that differs from @p->cpus_ptr and @p doesn't have full affinity. However, @is_prev_allowed was computed against the original (wider) @cpus_allowed, so the prev_cpu fast paths could pick a @prev_cpu that is in @cpus_allowed but not in @p->cpus_ptr, violating the intended invariant that the returned CPU is always usable by @p. The kernel masks this via the SCX_EV_SELECT_CPU_FALLBACK fallback, but the behavior contradicts the documented contract. Move the @is_prev_allowed evaluation past the narrowing block so it tests against the final @allowed mask. Fixes: ee9a4e92799d ("sched_ext: idle: Properly handle invalid prev_cpu during idle selection") Cc: stable@vger.kernel.org # v6.16+ Assisted-by: Claude <noreply@anthropic.com> Signed-off-by: David Carlier <devnexen@gmail.com> Reviewed-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 daystracing/probes: Limit size of event probe to 3KSteven Rostedt2-1/+9
commit b2aa3b4d64e460ac606f386c24e7d8a873ce6f1a upstream. There currently isn't a max limit an event probe can be. One could make an event greater than PAGE_SIZE, which makes the event useless because if it's bigger than the max event that can be recorded into the ring buffer, then it will never be recorded. A event probe should never need to be greater than 3K, so make that the max size. As long as the max is less than the max that can be recorded onto the ring buffer, it should be fine. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Fixes: 93ccae7a22274 ("tracing/kprobes: Support basic types on dynamic events") Link: https://patch.msgid.link/20260428122302.706610ba@gandalf.local.home Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 daysexit: prevent preemption of oopsing TASK_DEAD taskJann Horn1-0/+1
commit c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891 upstream. When an already-exiting task oopses, make_task_dead() currently calls do_task_dead() with preemption enabled. That is forbidden: do_task_dead() calls __schedule(), which has a comment saying "WARNING: must be called with preemption disabled!". If an oopsing task is preempted in do_task_dead(), between becoming TASK_DEAD and entering the scheduler explicitly, bad things happen: finish_task_switch() assumes that once the scheduler has switched away from a TASK_DEAD task, the task can never run again and its stack is no longer needed; but that assumption apparently doesn't hold if the dead task was preempted (the SM_PREEMPT case). This means that the scheduler ends up repeatedly dropping references on the dead task's stack, which can lead to use-after-free or double-free of the entire task stack; in other words, two tasks can end up running on the same stack, resulting in various kinds of memory corruption. (This does not just affect "recursively oopsing" tasks; it is enough to oops once during task exit, for example in a file_operations::release handler) Fixes: 7f80a2fd7db9 ("exit: Stop poorly open coding do_task_dead in make_task_dead") Cc: stable@kernel.org Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 daystracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()David Carlier1-0/+2
commit fad217e16fded7f3c09f8637b0f6a224d58b5f2e upstream. When a tracepoint goes through the 0 -> 1 transition, tracepoint_add_func() invokes the subsystem's ext->regfunc() before attempting to install the new probe via func_add(). If func_add() then fails (for example, when allocate_probes() cannot allocate a new probe array under memory pressure and returns -ENOMEM), the function returns the error without calling the matching ext->unregfunc(), leaving the side effects of regfunc() behind with no installed probe to justify them. For syscall tracepoints this is particularly unpleasant: syscall_regfunc() bumps sys_tracepoint_refcount and sets SYSCALL_TRACEPOINT on every task. After a leaked failure, the refcount is stuck at a non-zero value with no consumer, and every task continues paying the syscall trace entry/exit overhead until reboot. Other subsystems providing regfunc()/unregfunc() pairs exhibit similarly scoped persistent state. Mirror the existing 1 -> 0 cleanup and call ext->unregfunc() in the func_add() error path, gated on the same condition used there so the unwind is symmetric with the registration. Fixes: 8cf868affdc4 ("tracing: Have the reg function allow to fail") Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260413190601.21993-1-devnexen@gmail.com Signed-off-by: David Carlier <devnexen@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 daysrtmutex: Use waiter::task instead of current in remove_waiter()Keenan Dong1-5/+8
commit 3bfdc63936dd4773109b7b8c280c0f3b5ae7d349 upstream. remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ] Fixes: 8161239a8bcc ("rtmutex: Simplify PI algorithm and make highest prio task get lock") Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Signed-off-by: Keenan Dong <keenanat2000@gmail.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 daystaskstats: set version in TGID exit notificationsYiyang Chen1-0/+1
commit 16c4f0211aaa1ec1422b11b59f64f1abe9009fc0 upstream. delay accounting started populating taskstats records with a valid version field via fill_pid() and fill_tgid(). Later, commit ad4ecbcba728 ("[PATCH] delay accounting taskstats interface send tgid once") changed the TGID exit path to send the cached signal->stats aggregate directly instead of building the outgoing record through fill_tgid(). Unlike fill_tgid(), fill_tgid_exit() only accumulates accounting data and never initializes stats->version. As a result, TGID exit notifications can reach userspace with version == 0 even though PID exit notifications and TASKSTATS_CMD_GET replies carry a valid taskstats version. This is easy to reproduce with `tools/accounting/getdelays.c`. I have a small follow-up patch for that tool which: 1. increases the receive buffer/message size so the pid+tgid combined exit notification is not dropped/truncated 2. prints `stats->version`. With that patch, the reproducer is: Terminal 1: ./getdelays -d -v -l -m 0 Terminal 2: taskset -c 0 python3 -c 'import threading,time; t=threading.Thread(target=time.sleep,args=(0.1,)); t.start(); t.join()' That produces both PID and TGID exit notifications for the same process. The PID exit record reports a valid taskstats version, while the TGID exit record reports `version 0`. This patch (of 2): Set stats->version = TASKSTATS_VERSION after copying the cached TGID aggregate into the outgoing netlink payload so all taskstats records are self-describing again. Link: https://lkml.kernel.org/r/ba83d934e59edd431b693607de573eb9ca059309.1774810498.git.cyyzero16@gmail.com Fixes: ad4ecbcba728 ("[PATCH] delay accounting taskstats interface send tgid once") Signed-off-by: Yiyang Chen <cyyzero16@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dr. Thomas Orgis <thomas.orgis@uni-hamburg.de> Cc: Fan Yu <fan.yu9@zte.com.cn> Cc: Wang Yaxin <wang.yaxin@zte.com.cn> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 daysring-buffer: Do not double count the reader_pageMasami Hiramatsu (Google)1-6/+7
commit 92d5a606721f759ebebf448b3bd2b7a781d50bd0 upstream. Since the cpu_buffer->reader_page is updated if there are unwound pages. After that update, we should skip the page if it is the original reader_page, because the original reader_page is already checked. Cc: stable@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ian Rogers <irogers@google.com> Link: https://patch.msgid.link/177701353063.2223789.1471163147644103306.stgit@mhiramat.tok.corp.google.com Fixes: ca296d32ece3 ("tracing: ring_buffer: Rewind persistent ring buffer on reboot") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 daysrandomize_kstack: Maintain kstack_offset per taskRyan Roberts1-0/+2
commit 37beb42560165869838e7d91724f3e629db64129 upstream. kstack_offset was previously maintained per-cpu, but this caused a couple of issues. So let's instead make it per-task. Issue 1: add_random_kstack_offset() and choose_random_kstack_offset() expected and required to be called with interrupts and preemption disabled so that it could manipulate per-cpu state. But arm64, loongarch and risc-v are calling them with interrupts and preemption enabled. I don't _think_ this causes any functional issues, but it's certainly unexpected and could lead to manipulating the wrong cpu's state, which could cause a minor performance degradation due to bouncing the cache lines. By maintaining the state per-task those functions can safely be called in preemptible context. Issue 2: add_random_kstack_offset() is called before executing the syscall and expands the stack using a previously chosen random offset. choose_random_kstack_offset() is called after executing the syscall and chooses and stores a new random offset for the next syscall. With per-cpu storage for this offset, an attacker could force cpu migration during the execution of the syscall and prevent the offset from being updated for the original cpu such that it is predictable for the next syscall on that cpu. By maintaining the state per-task, this problem goes away because the per-task random offset is updated after the syscall regardless of which cpu it is executing on. Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall") Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/ Cc: stable@vger.kernel.org Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 daystracing/fprobe: Reject registration of a registered fprobe before initMasami Hiramatsu (Google)1-11/+10
commit 6ad51ada17ed80c9a5f205b4c01c424cac8b0d46 upstream. Reject registration of a registered fprobe which is on the fprobe hash table before initializing fprobe. The add_fprobe_hash() checks this re-register fprobe, but since fprobe_init() clears hlist_array field, it is too late to check it. It has to check the re-registration before touncing fprobe. Link: https://lore.kernel.org/all/177669364845.132053.18375367916162315835.stgit@mhiramat.tok.corp.google.com/ Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
11 dayssched: Use u64 for bandwidth ratio calculationsJoseph Salisbury3-3/+3
commit c6e80201e057dfb7253385e60bf541121bf5dc33 upstream. to_ratio() computes BW_SHIFT-scaled bandwidth ratios from u64 period and runtime values, but it returns unsigned long. tg_rt_schedulable() also stores the current group limit and the accumulated child sum in unsigned long. On 32-bit builds, large bandwidth ratios can be truncated and the RT group sum can wrap when enough siblings are present. That can let an overcommitted RT hierarchy pass the schedulability check, and it also narrows the helper result for other callers. Return u64 from to_ratio() and use u64 for the RT group totals so bandwidth ratios are preserved and compared at full width on both 32-bit and 64-bit builds. Fixes: b40b2e8eb521 ("sched: rt: multi level group constraints") Assisted-by: Codex:GPT-5 Signed-off-by: Joseph Salisbury <joseph.salisbury@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260403210014.2713404-1-joseph.salisbury@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-27sched/debug: Fix avg_vruntime() usagePeter Zijlstra1-1/+3
commit e08d007f9d813616ce7093600bc4fdb9c9d81d89 upstream. John reported that stress-ng-yield could make his machine unhappy and managed to bisect it to commit b3d99f43c72b ("sched/fair: Fix zero_vruntime tracking"). The commit in question changes avg_vruntime() from a function that is a pure reader, to a function that updates variables. This turns an unlocked sched/debug usage of this function from a minor mistake into a data corruptor. Fixes: af4cf40470c2 ("sched/fair: Add cfs_rq::avg_vruntime") Fixes: b3d99f43c72b ("sched/fair: Fix zero_vruntime tracking") Reported-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: John Stultz <jstultz@google.com> Link: https://patch.msgid.link/20260401132355.196370805@infradead.org Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22dma-debug: Allow multiple invocations of overlapping entriesLeon Romanovsky1-3/+3
commit eca58535b154e6951327319afda94ac80eae7dc3 upstream. Repeated DMA mappings with DMA_ATTR_CPU_CACHE_CLEAN trigger the following splat. This prevents using the attribute in cases where a DMA region is shared and reused more than seven times. ------------[ cut here ]------------ DMA-API: exceeded 7 overlapping mappings of cacheline 0x000000000438c440 WARNING: kernel/dma/debug.c:467 at add_dma_entry+0x219/0x280, CPU#4: ibv_rc_pingpong/1644 Modules linked in: xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay mlx5_fwctl zram zsmalloc mlx5_ib fuse rpcrdma rdma_ucm ib_uverbs ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_core ib_core CPU: 4 UID: 2733 PID: 1644 Comm: ibv_rc_pingpong Not tainted 6.19.0+ #129 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:add_dma_entry+0x221/0x280 Code: c0 0f 84 f2 fe ff ff 83 e8 01 89 05 6d 99 11 01 e9 e4 fe ff ff 0f 8e 1f ff ff ff 48 8d 3d 07 ef 2d 01 be 07 00 00 00 48 89 e2 <67> 48 0f b9 3a e9 06 ff ff ff 48 c7 c7 98 05 2b 82 c6 05 72 92 28 RSP: 0018:ff1100010e657970 EFLAGS: 00010002 RAX: 0000000000000007 RBX: ff1100010234eb00 RCX: 0000000000000000 RDX: ff1100010e657970 RSI: 0000000000000007 RDI: ffffffff82678660 RBP: 000000000438c440 R08: 0000000000000228 R09: 0000000000000000 R10: 00000000000001be R11: 000000000000089d R12: 0000000000000800 R13: 00000000ffffffef R14: 0000000000000202 R15: ff1100010234eb00 FS: 00007fb15f3f6740(0000) GS:ff110008dcc19000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb15f32d3a0 CR3: 0000000116f59001 CR4: 0000000000373eb0 Call Trace: <TASK> debug_dma_map_sg+0x1b4/0x390 __dma_map_sg_attrs+0x6d/0x1a0 dma_map_sgtable+0x19/0x30 ib_umem_get+0x284/0x3b0 [ib_uverbs] mlx5_ib_reg_user_mr+0x68/0x2a0 [mlx5_ib] ib_uverbs_reg_mr+0x17f/0x2a0 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xc2/0x130 [ib_uverbs] ib_uverbs_cmd_verbs+0xa0b/0xae0 [ib_uverbs] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT_SPEED+0xe0/0xe0 [ib_uverbs] ? mmap_region+0x7a/0xb0 ? do_mmap+0x3b8/0x5c0 ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs] __x64_sys_ioctl+0x14f/0x8b0 ? ksys_mmap_pgoff+0xc5/0x190 do_syscall_64+0x8c/0xbf0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fb15f5e4eed Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10 c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1a 48 8b 45 c8 64 48 2b 04 25 28 00 00 00 RSP: 002b:00007ffe09a5c540 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffe09a5c5d0 RCX: 00007fb15f5e4eed RDX: 00007ffe09a5c5f0 RSI: 00000000c0181b01 RDI: 0000000000000003 RBP: 00007ffe09a5c590 R08: 0000000000000028 R09: 00007ffe09a5c794 R10: 0000000000000001 R11: 0000000000000246 R12: 00007ffe09a5c794 R13: 000000000000000c R14: 0000000025a49170 R15: 000000000000000c </TASK> ---[ end trace 0000000000000000 ]--- Fixes: 61868dc55a11 ("dma-mapping: add DMA_ATTR_CPU_CACHE_CLEAN") Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20260316-dma-debug-overlap-v3-1-1dde90a7f08b@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22sched/deadline: Use revised wakeup rule for dl_serverPeter Zijlstra1-1/+1
[ Upstream commit 14a857056466be9d3d907a94e92a704ac1be149b ] John noted that commit 115135422562 ("sched/deadline: Fix 'stuck' dl_server") unfixed the issue from commit a3a70caf7906 ("sched/deadline: Fix dl_server behaviour"). The issue in commit 115135422562 was for wakeups of the server after the deadline; in which case you *have* to start a new period. The case for a3a70caf7906 is wakeups before the deadline. Now, because the server is effectively running a least-laxity policy, it means that any wakeup during the runnable phase means dl_entity_overflow() will be true. This means we need to adjust the runtime to allow it to still run until the existing deadline expires. Use the revised wakeup rule for dl_defer entities. Fixes: 115135422562 ("sched/deadline: Fix 'stuck' dl_server") Reported-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Tested-by: John Stultz <jstultz@google.com> Link: https://patch.msgid.link/20260404102244.GB22575@noisy.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-22tracing/probe: reject non-closed empty immediate stringsPengpeng Hou1-1/+1
[ Upstream commit 4346be6577aaa04586167402ae87bbdbe32484a4 ] parse_probe_arg() accepts quoted immediate strings and passes the body after the opening quote to __parse_imm_string(). That helper currently computes strlen(str) and immediately dereferences str[len - 1], which underflows when the body is empty and not closed with double-quotation. Reject empty non-closed immediate strings before checking for the closing quote. Link: https://lore.kernel.org/all/20260401160315.88518-1-pengpeng@iscas.ac.cn/ Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support") Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-22dma-debug: suppress cacheline overlap warning when arch has no DMA alignment ↵Mikhail Gavrilov1-0/+1
requirement [ Upstream commit 3d48c9fd78dd0b1809669ec49c4d0997b8127512 ] When CONFIG_DMA_API_DEBUG is enabled, the DMA debug infrastructure tracks active mappings per cacheline and warns if two different DMA mappings share the same cacheline ("cacheline tracking EEXIST, overlapping mappings aren't supported"). On x86_64, ARCH_KMALLOC_MINALIGN defaults to 8, so small kmalloc allocations (e.g. the 8-byte hub->buffer and hub->status in the USB hub driver) frequently land in the same 64-byte cacheline. When both are DMA-mapped, this triggers a false positive warning. This has been reported repeatedly since v5.14 (when the EEXIST check was added) across various USB host controllers and devices including xhci_hcd with USB hubs, USB audio devices, and USB ethernet adapters. The cacheline overlap is only a real concern on architectures that require DMA buffer alignment to cacheline boundaries (i.e. where ARCH_DMA_MINALIGN >= L1_CACHE_BYTES). On architectures like x86_64 where dma_get_cache_alignment() returns 1, the hardware is cache-coherent and overlapping cacheline mappings are harmless. Suppress the EEXIST warning when dma_get_cache_alignment() is less than L1_CACHE_BYTES, indicating the architecture does not require cacheline-aligned DMA buffers. Verified with a kernel module reproducer that performs two kmalloc(8) allocations back-to-back and DMA-maps both: Before: allocations share a cacheline, EEXIST fires within ~50 pairs After: same cacheline pair found, but no warning emitted Fixes: 2b4bbc6231d7 ("dma-debug: report -EEXIST errors in add_dma_entry") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215740 Suggested-by: Harry Yoo <harry@kernel.org> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20260327124156.24820-1-mikhail.v.gavrilov@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-22dma-debug: track cache clean flag in entriesMichael S. Tsirkin1-5/+22
[ Upstream commit d5d846513128c1a3bc2f2d371f6e903177dea443 ] If a driver is buggy and has 2 overlapping mappings but only sets cache clean flag on the 1st one of them, we warn. But if it only does it for the 2nd one, we don't. Fix by tracking cache clean flag in the entry. Message-ID: <0ffb3513d18614539c108b4548cdfbc64274a7d1.1767601130.git.mst@redhat.com> Reviewed-by: Petr Tesarik <ptesarik@suse.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Stable-dep-of: 3d48c9fd78dd ("dma-debug: suppress cacheline overlap warning when arch has no DMA alignment requirement") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-22dma-mapping: add DMA_ATTR_CPU_CACHE_CLEANMichael S. Tsirkin1-1/+2
[ Upstream commit 61868dc55a119a5e4b912d458fc2c48ba80a35fe ] When multiple small DMA_FROM_DEVICE or DMA_BIDIRECTIONAL buffers share a cacheline, and DMA_API_DEBUG is enabled, we get this warning: cacheline tracking EEXIST, overlapping mappings aren't supported. This is because when one of the mappings is removed, while another one is active, CPU might write into the buffer. Add an attribute for the driver to promise not to do this, making the overlapping safe, and suppressing the warning. Message-ID: <2d5d091f9d84b68ea96abd545b365dd1d00bbf48.1767601130.git.mst@redhat.com> Reviewed-by: Petr Tesarik <ptesarik@suse.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Stable-dep-of: 3d48c9fd78dd ("dma-debug: suppress cacheline overlap warning when arch has no DMA alignment requirement") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-18workqueue: Add pool_workqueue to pending_pwqs list when unplugging multiple ↵Matthew Brost1-1/+13
inactive works commit 703ccb63ae9f7444d6ff876d024e17f628103c69 upstream. In unplug_oldest_pwq(), the first inactive work item on the pool_workqueue is activated correctly. However, if multiple inactive works exist on the same pool_workqueue, subsequent works fail to activate because wq_node_nr_active.pending_pwqs is empty — the list insertion is skipped when the pool_workqueue is plugged. Fix this by checking for additional inactive works in unplug_oldest_pwq() and updating wq_node_nr_active.pending_pwqs accordingly. Fixes: 4c065dbce1e8 ("workqueue: Enable unbound cpumask update on ordered workqueues") Cc: stable@vger.kernel.org Cc: Carlos Santa <carlos.santa@intel.com> Cc: Ryan Neph <ryanneph@google.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Waiman Long <longman@redhat.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Matthew Brost <matthew.brost@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11sched_ext: Fix stale direct dispatch state in ddsp_dsq_idAndrea Righi1-14/+35
[ Upstream commit 7e0ffb72de8aa3b25989c2d980e81b829c577010 ] @p->scx.ddsp_dsq_id can be left set (non-SCX_DSQ_INVALID) triggering a spurious warning in mark_direct_dispatch() when the next wakeup's ops.select_cpu() calls scx_bpf_dsq_insert(), such as: WARNING: kernel/sched/ext.c:1273 at scx_dsq_insert_commit+0xcd/0x140 The root cause is that ddsp_dsq_id was only cleared in dispatch_enqueue(), which is not reached in all paths that consume or cancel a direct dispatch verdict. Fix it by clearing it at the right places: - direct_dispatch(): cache the direct dispatch state in local variables and clear it before dispatch_enqueue() on the synchronous path. For the deferred path, the direct dispatch state must remain set until process_ddsp_deferred_locals() consumes them. - process_ddsp_deferred_locals(): cache the dispatch state in local variables and clear it before calling dispatch_to_local_dsq(), which may migrate the task to another rq. - do_enqueue_task(): clear the dispatch state on the enqueue path (local/global/bypass fallbacks), where the direct dispatch verdict is ignored. - dequeue_task_scx(): clear the dispatch state after dispatch_dequeue() to handle both the deferred dispatch cancellation and the holding_cpu race, covering all cases where a pending direct dispatch is cancelled. - scx_disable_task(): clear the direct dispatch state when transitioning a task out of the current scheduler. Waking tasks may have had the direct dispatch state set by the outgoing scheduler's ops.select_cpu() and then been queued on a wake_list via ttwu_queue_wakelist(), when SCX_OPS_ALLOW_QUEUED_WAKEUP is set. Such tasks are not on the runqueue and are not iterated by scx_bypass(), so their direct dispatch state won't be cleared. Without this clear, any subsequent SCX scheduler that tries to direct dispatch the task will trigger the WARN_ON_ONCE() in mark_direct_dispatch(). Fixes: 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches") Cc: stable@vger.kernel.org # v6.12+ Cc: Daniel Hodges <hodgesd@meta.com> Cc: Patrick Somaru <patsomaru@meta.com> Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11sched_ext: Refactor do_enqueue_task() local and global DSQ pathsTejun Heo1-9/+12
[ Upstream commit 3546119f18647d7ddbba579737d8a222b430cb1c ] The local and global DSQ enqueue paths in do_enqueue_task() share the same slice refill logic. Factor out the common code into a shared enqueue label. This makes adding new enqueue cases easier. No functional changes. Reviewed-by: Andrea Righi <arighi@nvidia.com> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Tejun Heo <tj@kernel.org> Stable-dep-of: 7e0ffb72de8a ("sched_ext: Fix stale direct dispatch state in ddsp_dsq_id") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11kallsyms: prevent module removal when printing module name and buildidPetr Mladek1-0/+3
commit 3b07086444f80c844351255fd94c2cb0a7224df2 upstream. kallsyms_lookup_buildid() copies the symbol name into the given buffer so that it can be safely read anytime later. But it just copies pointers to mod->name and mod->build_id which might get reused after the related struct module gets removed. The lifetime of struct module is synchronized using RCU. Take the rcu read lock for the entire __sprint_symbol(). Link: https://lkml.kernel.org/r/20251128135920.217303-8-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Aaron Tomlin <atomlin@atomlin.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11kallsyms: cleanup code for appending the module buildidPetr Mladek1-9/+33
commit 8e81dac4cd5477731169b92cff7c24f8f6635950 upstream. Put the code for appending the optional "buildid" into a helper function, It makes __sprint_symbol() better readable. Also print a warning when the "modname" is set and the "buildid" isn't. It might catch a situation when some lookup function in kallsyms_lookup_buildid() does not handle the "buildid". Use pr_*_once() to avoid an infinite recursion when the function is called from printk(). The recursion is rather theoretical but better be on the safe side. Link: https://lkml.kernel.org/r/20251128135920.217303-5-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@atomlin.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11kallsyms: clean up modname and modbuildid initialization in ↵Petr Mladek1-4/+8
kallsyms_lookup_buildid() commit fda024fb64769e9d6b3916d013c78d6b189129f8 upstream. The @modname and @modbuildid optional return parameters are set only when the symbol is in a module. Always initialize them so that they do not need to be cleared when the module is not in a module. It simplifies the logic and makes the code even slightly more safe. Note that bpf_address_lookup() function will get updated in a separate patch. Link: https://lkml.kernel.org/r/20251128135920.217303-3-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@atomlin.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11kallsyms: clean up @namebuf initialization in kallsyms_lookup_buildid()Petr Mladek1-1/+6
commit 426295ef18c5d5f0b7f75ac89d09022fcfafd25c upstream. Patch series "kallsyms: Prevent invalid access when showing module buildid", v3. We have seen nested crashes in __sprint_symbol(), see below. They seem to be caused by an invalid pointer to "buildid". This patchset cleans up kallsyms code related to module buildid and fixes this invalid access when printing backtraces. I made an audit of __sprint_symbol() and found several situations when the buildid might be wrong: + bpf_address_lookup() does not set @modbuildid + ftrace_mod_address_lookup() does not set @modbuildid + __sprint_symbol() does not take rcu_read_lock and the related struct module might get removed before mod->build_id is printed. This patchset solves these problems: + 1st, 2nd patches are preparatory + 3rd, 4th, 6th patches fix the above problems + 5th patch cleans up a suspicious initialization code. This is the backtrace, we have seen. But it is not really important. The problems fixed by the patchset are obvious: crash64> bt [62/2029] PID: 136151 TASK: ffff9f6c981d4000 CPU: 367 COMMAND: "btrfs" #0 [ffffbdb687635c28] machine_kexec at ffffffffb4c845b3 #1 [ffffbdb687635c80] __crash_kexec at ffffffffb4d86a6a #2 [ffffbdb687635d08] hex_string at ffffffffb51b3b61 #3 [ffffbdb687635d40] crash_kexec at ffffffffb4d87964 #4 [ffffbdb687635d50] oops_end at ffffffffb4c41fc8 #5 [ffffbdb687635d70] do_trap at ffffffffb4c3e49a #6 [ffffbdb687635db8] do_error_trap at ffffffffb4c3e6a4 #7 [ffffbdb687635df8] exc_stack_segment at ffffffffb5666b33 #8 [ffffbdb687635e20] asm_exc_stack_segment at ffffffffb5800cf9 ... This patch (of 7) The function kallsyms_lookup_buildid() initializes the given @namebuf by clearing the first and the last byte. It is not clear why. The 1st byte makes sense because some callers ignore the return code and expect that the buffer contains a valid string, for example: - function_stat_show() - kallsyms_lookup() - kallsyms_lookup_buildid() The initialization of the last byte does not make much sense because it can later be overwritten. Fortunately, it seems that all called functions behave correctly: - kallsyms_expand_symbol() explicitly adds the trailing '\0' at the end of the function. - All *__address_lookup() functions either use the safe strscpy() or they do not touch the buffer at all. Document the reason for clearing the first byte. And remove the useless initialization of the last byte. Link: https://lkml.kernel.org/r/20251128135920.217303-2-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Aaron Tomlin <atomlin@atomlin.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Daniel Gomez <da.gomez@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11sched_ext: Fix is_bpf_migration_disabled() false negative on non-PREEMPT_RCUChangwoo Min1-12/+19
commit 0c4a59df370bea245695c00aaae6ae75747139bd upstream. Since commit 8e4f0b1ebcf2 ("bpf: use rcu_read_lock_dont_migrate() for trampoline.c"), the BPF prolog (__bpf_prog_enter) calls migrate_disable() only when CONFIG_PREEMPT_RCU is enabled, via rcu_read_lock_dont_migrate(). Without CONFIG_PREEMPT_RCU, the prolog never touches migration_disabled, so migration_disabled == 1 always means the task is truly migration-disabled regardless of whether it is the current task. The old unconditional p == current check was a false negative in this case, potentially allowing a migration-disabled task to be dispatched to a remote CPU and triggering scx_error in task_can_run_on_remote_rq(). Only apply the p == current disambiguation when CONFIG_PREEMPT_RCU is enabled, where the ambiguity with the BPF prolog still exists. Fixes: 8e4f0b1ebcf2 ("bpf: use rcu_read_lock_dont_migrate() for trampoline.c") Cc: stable@vger.kernel.org # v6.18+ Link: https://lore.kernel.org/lkml/20250821090609.42508-8-dongml2@chinatelecom.cn/ Signed-off-by: Changwoo Min <changwoo@igalia.com> Reviewed-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11sched_ext: Fix inconsistent NUMA node lookup in scx_select_cpu_dfl()Cheng-Yang Chou1-1/+1
commit db08b1940f4beb25460b4a4e9da3446454f2e8fe upstream. In the WAKE_SYNC path of scx_select_cpu_dfl(), waker_node was computed with cpu_to_node(), while node (for prev_cpu) was computed with scx_cpu_node_if_enabled(). When scx_builtin_idle_per_node is disabled, idle_cpumask(waker_node) is called with a real node ID even though per-node idle tracking is disabled, resulting in undefined behavior. Fix by using scx_cpu_node_if_enabled() for waker_node as well, ensuring both variables are computed consistently. Fixes: 48849271e6611 ("sched_ext: idle: Per-node idle cpumasks") Cc: stable@vger.kernel.org # v6.15+ Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com> Reviewed-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11sched/fair: Fix zero_vruntime tracking fixPeter Zijlstra1-7/+3
[ Upstream commit 1319ea57529e131822bab56bf417c8edc2db9ae8 ] John reported that stress-ng-yield could make his machine unhappy and managed to bisect it to commit b3d99f43c72b ("sched/fair: Fix zero_vruntime tracking"). The combination of yield and that commit was specific enough to hypothesize the following scenario: Suppose we have 2 runnable tasks, both doing yield. Then one will be eligible and one will not be, because the average position must be in between these two entities. Therefore, the runnable task will be eligible, and be promoted a full slice (all the tasks do is yield after all). This causes it to jump over the other task and now the other task is eligible and current is no longer. So we schedule. Since we are runnable, there is no {de,en}queue. All we have is the __{en,de}queue_entity() from {put_prev,set_next}_task(). But per the fingered commit, those two no longer move zero_vruntime. All that moves zero_vruntime are tick and full {de,en}queue. This means, that if the two tasks playing leapfrog can reach the critical speed to reach the overflow point inside one tick's worth of time, we're up a creek. Additionally, when multiple cgroups are involved, there is no guarantee the tick will in fact hit every cgroup in a timely manner. Statistically speaking it will, but that same statistics does not rule out the possibility of one cgroup not getting a tick for a significant amount of time -- however unlikely. Therefore, just like with the yield() case, force an update at the end of every slice. This ensures the update is never more than a single slice behind and the whole thing is within 2 lag bounds as per the comment on entity_key(). Fixes: b3d99f43c72b ("sched/fair: Fix zero_vruntime tracking") Reported-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: John Stultz <jstultz@google.com> Link: https://patch.msgid.link/20260401132355.081530332@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-11bpf: Reject sleepable kprobe_multi programs at attach timeVarun R Mallya1-0/+4
[ Upstream commit eb7024bfcc5f68ed11ed9dd4891a3073c15f04a8 ] kprobe.multi programs run in atomic/RCU context and cannot sleep. However, bpf_kprobe_multi_link_attach() did not validate whether the program being attached had the sleepable flag set, allowing sleepable helpers such as bpf_copy_from_user() to be invoked from a non-sleepable context. This causes a "sleeping function called from invalid context" splat: BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:169 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1787, name: sudo preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 0 Fix this by rejecting sleepable programs early in bpf_kprobe_multi_link_attach(), before any further processing. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Varun R Mallya <varunrmallya@gmail.com> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: Leon Hwang <leon.hwang@linux.dev> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20260401191126.440683-1-varunrmallya@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-11bpf: reject direct access to nullable PTR_TO_BUF pointersQi Tang1-1/+2
[ Upstream commit b0db1accbc7395657c2b79db59fa9fae0d6656f3 ] check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check. Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference. Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern. Fixes: 20b2aff4bc15 ("bpf: Introduce MEM_RDONLY flag") Signed-off-by: Qi Tang <tpluszz77@gmail.com> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260402092923.38357-2-tpluszz77@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-11bpf: Fix regsafe() for pointers to packetAlexei Starovoitov1-1/+6
[ Upstream commit a8502a79e832b861e99218cbd2d8f4312d62e225 ] In case rold->reg->range == BEYOND_PKT_END && rcur->reg->range == N regsafe() may return true which may lead to current state with valid packet range not being explored. Fix the bug. Fixes: 6d94e741a8ff ("bpf: Support for pointers beyond pkt_end.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Amery Hung <ameryhung@gmail.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20260331204228.26726-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-02futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()Hao-Yu Yang1-1/+1
[ Upstream commit 190a8c48ff623c3d67cb295b4536a660db2012aa ] During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free(). This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode. [ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87 [ 151.415969] Call Trace: [ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593) Fix by adding rcu to __mpol_put(). Fixes: c042c505210d ("futex: Implement FUTEX2_MPOL") Reported-by: Hao-Yu Yang <naup96721@gmail.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Hao-Yu Yang <naup96721@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Link: https://patch.msgid.link/20260324174418.GB1850007@noisy.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-04-02futex: Require sys_futex_requeue() to have identical flagsPeter Zijlstra1-0/+8
[ Upstream commit 19f94b39058681dec64a10ebeb6f23fe7fc3f77a ] Nicholas reported that his LLM found it was possible to create a UaF when sys_futex_requeue() is used with different flags. The initial motivation for allowing different flags was the variable sized futex, but since that hasn't been merged (yet), simply mandate the flags are identical, as is the case for the old style sys_futex() requeue operations. Fixes: 0f4b5f972216 ("futex: Add sys_futex_requ