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2023-02-25sched/psi: Stop relying on timer_pending() for poll_work reschedulingSuren Baghdasaryan1-10/+52
[ Upstream commit 710ffe671e014d5ccbcff225130a178b088ef090 ] Psi polling mechanism is trying to minimize the number of wakeups to run psi_poll_work and is currently relying on timer_pending() to detect when this work is already scheduled. This provides a window of opportunity for psi_group_change to schedule an immediate psi_poll_work after poll_timer_fn got called but before psi_poll_work could reschedule itself. Below is the depiction of this entire window: poll_timer_fn wake_up_interruptible(&group->poll_wait); psi_poll_worker wait_event_interruptible(group->poll_wait, ...) psi_poll_work psi_schedule_poll_work if (timer_pending(&group->poll_timer)) return; ... mod_timer(&group->poll_timer, jiffies + delay); Prior to 461daba06bdc we used to rely on poll_scheduled atomic which was reset and set back inside psi_poll_work and therefore this race window was much smaller. The larger window causes increased number of wakeups and our partners report visible power regression of ~10mA after applying 461daba06bdc. Bring back the poll_scheduled atomic and make this race window even narrower by resetting poll_scheduled only when we reach polling expiration time. This does not completely eliminate the possibility of extra wakeups caused by a race with psi_group_change however it will limit it to the worst case scenario of one extra wakeup per every tracking window (0.5s in the worst case). This patch also ensures correct ordering between clearing poll_scheduled flag and obtaining changed_states using memory barrier. Correct ordering between updating changed_states and setting poll_scheduled is ensured by atomic_xchg operation. By tracing the number of immediate rescheduling attempts performed by psi_group_change and the number of these attempts being blocked due to psi monitor being already active, we can assess the effects of this change: Before the patch: Run#1 Run#2 Run#3 Immediate reschedules attempted: 684365 1385156 1261240 Immediate reschedules blocked: 682846 1381654 1258682 Immediate reschedules (delta): 1519 3502 2558 Immediate reschedules (% of attempted): 0.22% 0.25% 0.20% After the patch: Run#1 Run#2 Run#3 Immediate reschedules attempted: 882244 770298 426218 Immediate reschedules blocked: 881996 769796 426074 Immediate reschedules (delta): 248 502 144 Immediate reschedules (% of attempted): 0.03% 0.07% 0.03% The number of non-blocked immediate reschedules dropped from 0.22-0.25% to 0.03-0.07%. The drop is attributed to the decrease in the race window size and the fact that we allow this race only when psi monitors reach polling window expiration time. Fixes: 461daba06bdc ("psi: eliminate kthread_worker from psi trigger scheduling mechanism") Reported-by: Kathleen Chang <yt.chang@mediatek.com> Reported-by: Wenju Xu <wenju.xu@mediatek.com> Reported-by: Jonathan Chen <jonathan.jmchen@mediatek.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: SH Chen <show-hong.chen@mediatek.com> Link: https://lore.kernel.org/r/20221028194541.813985-1-surenb@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-22alarmtimer: Prevent starvation by small intervals and SIG_IGNThomas Gleixner1-4/+29
commit d125d1349abeb46945dc5e98f7824bf688266f13 upstream. syzbot reported a RCU stall which is caused by setting up an alarmtimer with a very small interval and ignoring the signal. The reproducer arms the alarm timer with a relative expiry of 8ns and an interval of 9ns. Not a problem per se, but that's an issue when the signal is ignored because then the timer is immediately rearmed because there is no way to delay that rearming to the signal delivery path. See posix_timer_fn() and commit 58229a189942 ("posix-timers: Prevent softirq starvation by small intervals and SIG_IGN") for details. The reproducer does not set SIG_IGN explicitely, but it sets up the timers signal with SIGCONT. That has the same effect as explicitely setting SIG_IGN for a signal as SIGCONT is ignored if there is no handler set and the task is not ptraced. The log clearly shows that: [pid 5102] --- SIGCONT {si_signo=SIGCONT, si_code=SI_TIMER, si_timerid=0, si_overrun=316014, si_int=0, si_ptr=NULL} --- It works because the tasks are traced and therefore the signal is queued so the tracer can see it, which delays the restart of the timer to the signal delivery path. But then the tracer is killed: [pid 5087] kill(-5102, SIGKILL <unfinished ...> ... ./strace-static-x86_64: Process 5107 detached and after it's gone the stall can be observed: syzkaller login: [ 79.439102][ C0] hrtimer: interrupt took 68471 ns [ 184.460538][ C1] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: ... [ 184.658237][ C1] rcu: Stack dump where RCU GP kthread last ran: [ 184.664574][ C1] Sending NMI from CPU 1 to CPUs 0: [ 184.669821][ C0] NMI backtrace for cpu 0 [ 184.669831][ C0] CPU: 0 PID: 5108 Comm: syz-executor192 Not tainted 6.2.0-rc6-next-20230203-syzkaller #0 ... [ 184.670036][ C0] Call Trace: [ 184.670041][ C0] <IRQ> [ 184.670045][ C0] alarmtimer_fired+0x327/0x670 posix_timer_fn() prevents that by checking whether the interval for timers which have the signal ignored is smaller than a jiffie and artifically delay it by shifting the next expiry out by a jiffie. That's accurate vs. the overrun accounting, but slightly inaccurate vs. timer_gettimer(2). The comment in that function says what needs to be done and there was a fix available for the regular userspace induced SIG_IGN mechanism, but that did not work due to the implicit ignore for SIGCONT and similar signals. This needs to be worked on, but for now the only available workaround is to do exactly what posix_timer_fn() does: Increase the interval of self-rearming timers, which have their signal ignored, to at least a jiffie. Interestingly this has been fixed before via commit ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") already, but that fix got lost in a later rework. Reported-by: syzbot+b9564ba6e8e00694511b@syzkaller.appspotmail.com Fixes: f2c45807d399 ("alarmtimer: Switch over to generic set/get/rearm routine") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87k00q1no2.ffs@tglx Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22tracing: Make trace_define_field_ext() staticSteven Rostedt (Google)1-1/+1
commit 70b5339caf847b8b6097b6dfab0c5a99b40713c8 upstream. trace_define_field_ext() is not used outside of trace_events.c, it should be static. Link: https://lore.kernel.org/oe-kbuild-all/202302130750.679RaRog-lkp@intel.com/ Fixes: b6c7abd1c28a ("tracing: Fix TASK_COMM_LEN in trace event format file") Reported-by: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22freezer,umh: Fix call_usermode_helper_exec() vs SIGKILLPeter Zijlstra1-7/+13
commit eedeb787ebb53de5c5dcf7b7b39d01bf1b0f037d upstream. Tetsuo-San noted that commit f5d39b020809 ("freezer,sched: Rewrite core freezer logic") broke call_usermodehelper_exec() for the KILLABLE case. Specifically it was missed that the second, unconditional, wait_for_completion() was not optional and ensures the on-stack completion is unused before going out-of-scope. Fixes: f5d39b020809 ("freezer,sched: Rewrite core freezer logic") Reported-by: syzbot+6cd18e123583550cf469@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Debugged-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Y90ar35uKQoUrLEK@hirez.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22sched/psi: Fix use-after-free in ep_remove_wait_queue()Munehisa Kamata1-3/+4
commit c2dbe32d5db5c4ead121cf86dabd5ab691fb47fe upstream. If a non-root cgroup gets removed when there is a thread that registered trigger and is polling on a pressure file within the cgroup, the polling waitqueue gets freed in the following path: do_rmdir cgroup_rmdir kernfs_drain_open_files cgroup_file_release cgroup_pressure_release psi_trigger_destroy However, the polling thread still has a reference to the pressure file and will access the freed waitqueue when the file is closed or upon exit: fput ep_eventpoll_release ep_free ep_remove_wait_queue remove_wait_queue This results in use-after-free as pasted below. The fundamental problem here is that cgroup_file_release() (and consequently waitqueue's lifetime) is not tied to the file's real lifetime. Using wake_up_pollfree() here might be less than ideal, but it is in line with the comment at commit 42288cb44c4b ("wait: add wake_up_pollfree()") since the waitqueue's lifetime is not tied to file's one and can be considered as another special case. While this would be fixable by somehow making cgroup_file_release() be tied to the fput(), it would require sizable refactoring at cgroups or higher layer which might be more justifiable if we identify more cases like this. BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0 Write of size 4 at addr ffff88810e625328 by task a.out/4404 CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38 Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017 Call Trace: <TASK> dump_stack_lvl+0x73/0xa0 print_report+0x16c/0x4e0 kasan_report+0xc3/0xf0 kasan_check_range+0x2d2/0x310 _raw_spin_lock_irqsave+0x60/0xc0 remove_wait_queue+0x1a/0xa0 ep_free+0x12c/0x170 ep_eventpoll_release+0x26/0x30 __fput+0x202/0x400 task_work_run+0x11d/0x170 do_exit+0x495/0x1130 do_group_exit+0x100/0x100 get_signal+0xd67/0xde0 arch_do_signal_or_restart+0x2a/0x2b0 exit_to_user_mode_prepare+0x94/0x100 syscall_exit_to_user_mode+0x20/0x40 do_syscall_64+0x52/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Allocated by task 4404: kasan_set_track+0x3d/0x60 __kasan_kmalloc+0x85/0x90 psi_trigger_create+0x113/0x3e0 pressure_write+0x146/0x2e0 cgroup_file_write+0x11c/0x250 kernfs_fop_write_iter+0x186/0x220 vfs_write+0x3d8/0x5c0 ksys_write+0x90/0x110 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4407: kasan_set_track+0x3d/0x60 kasan_save_free_info+0x27/0x40 ____kasan_slab_free+0x11d/0x170 slab_free_freelist_hook+0x87/0x150 __kmem_cache_free+0xcb/0x180 psi_trigger_destroy+0x2e8/0x310 cgroup_file_release+0x4f/0xb0 kernfs_drain_open_files+0x165/0x1f0 kernfs_drain+0x162/0x1a0 __kernfs_remove+0x1fb/0x310 kernfs_remove_by_name_ns+0x95/0xe0 cgroup_addrm_files+0x67f/0x700 cgroup_destroy_locked+0x283/0x3c0 cgroup_rmdir+0x29/0x100 kernfs_iop_rmdir+0xd1/0x140 vfs_rmdir+0xfe/0x240 do_rmdir+0x13d/0x280 __x64_sys_rmdir+0x2c/0x30 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 0e94682b73bf ("psi: introduce psi monitor") Signed-off-by: Munehisa Kamata <kamatam@amazon.com> Signed-off-by: Mengchi Cheng <mengcc@amazon.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/ Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-14rtmutex: Ensure that the top waiter is always woken upWander Lairson Costa1-2/+3
commit db370a8b9f67ae5f17e3d5482493294467784504 upstream. Let L1 and L2 be two spinlocks. Let T1 be a task holding L1 and blocked on L2. T1, currently, is the top waiter of L2. Let T2 be the task holding L2. Let T3 be a task trying to acquire L1. The following events will lead to a state in which the wait queue of L2 isn't empty, but no task actually holds the lock. T1 T2 T3 == == == spin_lock(L1) | raw_spin_lock(L1->wait_lock) | rtlock_slowlock_locked(L1) | | task_blocks_on_rt_mutex(L1, T3) | | | orig_waiter->lock = L1 | | | orig_waiter->task = T3 | | | raw_spin_unlock(L1->wait_lock) | | | rt_mutex_adjust_prio_chain(T1, L1, L2, orig_waiter, T3) spin_unlock(L2) | | | | | rt_mutex_slowunlock(L2) | | | | | | raw_spin_lock(L2->wait_lock) | | | | | | wakeup(T1) | | | | | | raw_spin_unlock(L2->wait_lock) | | | | | | | | waiter = T1->pi_blocked_on | | | | waiter == rt_mutex_top_waiter(L2) | | | | waiter->task == T1 | | | | raw_spin_lock(L2->wait_lock) | | | | dequeue(L2, waiter) | | | | update_prio(waiter, T1) | | | | enqueue(L2, waiter) | | | | waiter != rt_mutex_top_waiter(L2) | | | | L2->owner == NULL | | | | wakeup(T1) | | | | raw_spin_unlock(L2->wait_lock) T1 wakes up T1 != top_waiter(L2) schedule_rtlock() If the deadline of T1 is updated before the call to update_prio(), and the new deadline is greater than the deadline of the second top waiter, then after the requeue, T1 is no longer the top waiter, and the wrong task is woken up which will then go back to sleep because it is not the top waiter. This can be reproduced in PREEMPT_RT with stress-ng: while true; do stress-ng --sched deadline --sched-period 1000000000 \ --sched-runtime 800000000 --sched-deadline \ 1000000000 --mmapfork 23 -t 20 done A similar issue was pointed out by Thomas versus the cases where the top waiter drops out early due to a signal or timeout, which is a general issue for all regular rtmutex use cases, e.g. futex. The problematic code is in rt_mutex_adjust_prio_chain(): // Save the top waiter before dequeue/enqueue prerequeue_top_waiter = rt_mutex_top_waiter(lock); rt_mutex_dequeue(lock, waiter); waiter_update_prio(waiter, task); rt_mutex_enqueue(lock, waiter); // Lock has no owner? if (!rt_mutex_owner(lock)) { // Top waiter changed ----> if (prerequeue_top_waiter != rt_mutex_top_waiter(lock)) ----> wake_up_state(waiter->task, waiter->wake_state); This only takes the case into account where @waiter is the new top waiter due to the requeue operation. But it fails to handle the case where @waiter is not longer the top waiter due to the requeue operation. Ensure that the new top waiter is woken up so in all cases so it can take over the ownerless lock. [ tglx: Amend changelog, add Fixes tag ] Fixes: c014ef69b3ac ("locking/rtmutex: Add wake_state to rt_mutex_waiter") Signed-off-by: Wander Lairson Costa <wander@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230117172649.52465-1-wander@redhat.com Link: https://lore.kernel.org/r/20230202123020.14844-1-wander@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-14tracing: Fix TASK_COMM_LEN in trace event format fileYafang Shao3-10/+33
commit b6c7abd1c28a63ad633433d037ee15a1bc3023ba upstream. After commit 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN"), the content of the format file under /sys/kernel/tracing/events/task/task_newtask was changed from field:char comm[16]; offset:12; size:16; signed:0; to field:char comm[TASK_COMM_LEN]; offset:12; size:16; signed:0; John reported that this change breaks older versions of perfetto. Then Mathieu pointed out that this behavioral change was caused by the use of __stringify(_len), which happens to work on macros, but not on enum labels. And he also gave the suggestion on how to fix it: :One possible solution to make this more robust would be to extend :struct trace_event_fields with one more field that indicates the length :of an array as an actual integer, without storing it in its stringified :form in the type, and do the formatting in f_show where it belongs. The result as follows after this change, $ cat /sys/kernel/tracing/events/task/task_newtask/format field:char comm[16]; offset:12; size:16; signed:0; Link: https://lore.kernel.org/lkml/Y+QaZtz55LIirsUO@google.com/ Link: https://lore.kernel.org/linux-trace-kernel/20230210155921.4610-1-laoar.shao@gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20230212151303.12353-1-laoar.shao@gmail.com Cc: stable@vger.kernel.org Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Kajetan Puchalski <kajetan.puchalski@arm.com> CC: Qais Yousef <qyousef@layalina.io> Fixes: 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN") Reported-by: John Stultz <jstultz@google.com> Debugged-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-14cpuset: Call set_cpus_allowed_ptr() with appropriate mask for taskWill Deacon1-7/+11
[ Upstream commit 7a2127e66a00e073db8d90f9aac308f4a8a64226 ] set_cpus_allowed_ptr() will fail with -EINVAL if the requested affinity mask is not a subset of the task_cpu_possible_mask() for the task being updated. Consequently, on a heterogeneous system with cpusets spanning the different CPU types, updates to the cgroup hierarchy can silently fail to update task affinities when the effective affinity mask for the cpuset is expanded. For example, consider an arm64 system with 4 CPUs, where CPUs 2-3 are the only cores capable of executing 32-bit tasks. Attaching a 32-bit task to a cpuset containing CPUs 0-2 will correctly affine the task to CPU 2. Extending the cpuset to CPUs 0-3, however, will fail to extend the affinity mask of the 32-bit task because update_tasks_cpumask() will pass the full 0-3 mask to set_cpus_allowed_ptr(). Extend update_tasks_cpumask() to take a temporary 'cpumask' paramater and use it to mask the 'effective_cpus' mask with the possible mask for each task being updated. Fixes: 431c69fac05b ("cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()") Signed-off-by: Will Deacon <will@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-14tracing: Fix poll() and select() do not work on per_cpu trace_pipe and ↵Shiju Jose1-3/+0
trace_pipe_raw commit 3e46d910d8acf94e5360126593b68bf4fee4c4a1 upstream. poll() and select() on per_cpu trace_pipe and trace_pipe_raw do not work since kernel 6.1-rc6. This issue is seen after the commit 42fb0a1e84ff525ebe560e2baf9451ab69127e2b ("tracing/ring-buffer: Have polling block on watermark"). This issue is firstly detected and reported, when testing the CXL error events in the rasdaemon and also erified using the test application for poll() and select(). This issue occurs for the per_cpu case, when calling the ring_buffer_poll_wait(), in kernel/trace/ring_buffer.c, with the buffer_percent > 0 and then wait until the percentage of pages are available. The default value set for the buffer_percent is 50 in the kernel/trace/trace.c. As a fix, allow userspace application could set buffer_percent as 0 through the buffer_percent_fops, so that the task will wake up as soon as data is added to any of the specific cpu buffer. Link: https://lore.kernel.org/linux-trace-kernel/20230202182309.742-2-shiju.jose@huawei.com Cc: <mhiramat@kernel.org> Cc: <mchehab@kernel.org> Cc: <linux-edac@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: 42fb0a1e84ff5 ("tracing/ring-buffer: Have polling block on watermark") Signed-off-by: Shiju Jose <shiju.jose@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09bpf: Skip invalid kfunc call in backtrack_insnHao Sun1-0/+6
commit d3178e8a434b58678d99257c0387810a24042fb6 upstream. The verifier skips invalid kfunc call in check_kfunc_call(), which would be captured in fixup_kfunc_call() if such insn is not eliminated by dead code elimination. However, this can lead to the following warning in backtrack_insn(), also see [1]: ------------[ cut here ]------------ verifier backtracking bug WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn kernel/bpf/verifier.c:2756 __mark_chain_precision kernel/bpf/verifier.c:3065 mark_chain_precision kernel/bpf/verifier.c:3165 adjust_reg_min_max_vals kernel/bpf/verifier.c:10715 check_alu_op kernel/bpf/verifier.c:10928 do_check kernel/bpf/verifier.c:13821 [inline] do_check_common kernel/bpf/verifier.c:16289 [...] So make backtracking conservative with this by returning ENOTSUPP. [1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/ Reported-by: syzbot+4da3ff23081bafe74fc2@syzkaller.appspotmail.com Signed-off-by: Hao Sun <sunhao.th@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230104014709.9375-1-sunhao.th@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09kernel/irq/irqdomain.c: fix memory leak with using debugfs_lookup()Greg Kroah-Hartman1-1/+1
commit d83d7ed260283560700d4034a80baad46620481b upstream. When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable <stable@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230202151554.2310273-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()Waiman Long1-1/+2
commit e5ae8803847b80fe9d744a3174abe2b7bfed222a upstream. It was found that the check to see if a partition could use up all the cpus from the parent cpuset in update_parent_subparts_cpumask() was incorrect. As a result, it is possible to leave parent with no effective cpu left even if there are tasks in the parent cpuset. This can lead to system panic as reported in [1]. Fix this probem by updating the check to fail the enabling the partition if parent's effective_cpus is a subset of the child's cpus_allowed. Also record the error code when an error happens in update_prstate() and add a test case where parent partition and child have the same cpu list and parent has task. Enabling partition in the child will fail in this case. [1] https://www.spinics.net/lists/cgroups/msg36254.html Fixes: f0af1bfc27b5 ("cgroup/cpuset: Relax constraints to partition & cpus changes") Cc: stable@vger.kernel.org # v6.1 Reported-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09use less confusing names for iov_iter direction initializersAl Viro1-1/+1
[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ] READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Stable-dep-of: 6dd88fd59da8 ("vhost-scsi: unbreak any layout for response") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09bpf: Fix the kernel crash caused by bpf_setsockopt().Kui-Feng Lee1-1/+0
[ Upstream commit 5416c9aea8323583e8696f0500b6142dfae80821 ] The kernel crash was caused by a BPF program attached to the "lsm_cgroup/socket_sock_rcv_skb" hook, which performed a call to `bpf_setsockopt()` in order to set the TCP_NODELAY flag as an example. Flags like TCP_NODELAY can prompt the kernel to flush a socket's outgoing queue, and this hook "lsm_cgroup/socket_sock_rcv_skb" is frequently triggered by softirqs. The issue was that in certain circumstances, when `tcp_write_xmit()` was called to flush the queue, it would also allow BH (bottom-half) to run. This could lead to our program attempting to flush the same socket recursively, which caused a `skbuff` to be unlinked twice. `security_sock_rcv_skb()` is triggered by `tcp_filter()`. This occurs before the sock ownership is checked in `tcp_v4_rcv()`. Consequently, if a bpf program runs on `security_sock_rcv_skb()` while under softirq conditions, it may not possess the lock needed for `bpf_setsockopt()`, thus presenting an issue. The patch fixes this issue by ensuring that a BPF program attached to the "lsm_cgroup/socket_sock_rcv_skb" hook is not allowed to call `bpf_setsockopt()`. The differences from v1 are - changing commit log to explain holding the lock of the sock, - emphasizing that TCP_NODELAY is not the only flag, and - adding the fixes tag. v1: https://lore.kernel.org/bpf/20230125000244.1109228-1-kuifeng@meta.com/ Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Fixes: 9113d7e48e91 ("bpf: expose bpf_{g,s}etsockopt to lsm cgroup") Link: https://lore.kernel.org/r/20230127001732.4162630-1-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09bpf: Add missing btf_put to register_btf_id_dtor_kfuncsJiri Olsa1-2/+2
[ Upstream commit 74bc3a5acc82f020d2e126f56c535d02d1e74e37 ] We take the BTF reference before we register dtors and we need to put it back when it's done. We probably won't se a problem with kernel BTF, but module BTF would stay loaded (because of the extra ref) even when its module is removed. Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Fixes: 5ce937d613a4 ("bpf: Populate pairs of btf_id and destructor kfunc in btf") Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230120122148.1522359-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09bpf: Fix to preserve reg parent/live fields when copying range infoEduard Zingerman1-7/+18
[ Upstream commit 71f656a50176915d6813751188b5758daa8d012b ] Register range information is copied in several places. The intent is to transfer range/id information from one register/stack spill to another. Currently this is done using direct register assignment, e.g.: static void find_equal_scalars(..., struct bpf_reg_state *known_reg) { ... struct bpf_reg_state *reg; ... *reg = *known_reg; ... } However, such assignments also copy the following bpf_reg_state fields: struct bpf_reg_state { ... struct bpf_reg_state *parent; ... enum bpf_reg_liveness live; ... }; Copying of these fields is accidental and incorrect, as could be demonstrated by the following example: 0: call ktime_get_ns() 1: r6 = r0 2: call ktime_get_ns() 3: r7 = r0 4: if r0 > r6 goto +1 ; r0 & r6 are unbound thus generated ; branch states are identical 5: *(u64 *)(r10 - 8) = 0xdeadbeef ; 64-bit write to fp[-8] --- checkpoint --- 6: r1 = 42 ; r1 marked as written 7: *(u8 *)(r10 - 8) = r1 ; 8-bit write, fp[-8] parent & live ; overwritten 8: r2 = *(u64 *)(r10 - 8) 9: r0 = 0 10: exit This example is unsafe because 64-bit write to fp[-8] at (5) is conditional, thus not all bytes of fp[-8] are guaranteed to be set when it is read at (8). However, currently the example passes verification. First, the execution path 1-10 is examined by verifier. Suppose that a new checkpoint is created by is_state_visited() at (6). After checkpoint creation: - r1.parent points to checkpoint.r1, - fp[-8].parent points to checkpoint.fp[-8]. At (6) the r1.live is set to REG_LIVE_WRITTEN. At (7) the fp[-8].parent is set to r1.parent and fp[-8].live is set to REG_LIVE_WRITTEN, because of the following code called in check_stack_write_fixed_off(): static void save_register_state(struct bpf_func_state *state, int spi, struct bpf_reg_state *reg, int size) { ... state->stack[spi].spilled_ptr = *reg; // <--- parent & live copied if (size == BPF_REG_SIZE) state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN; ... } Note the intent to mark stack spill as written only if 8 bytes are spilled to a slot, however this intent is spoiled by a 'live' field copy. At (8) the checkpoint.fp[-8] should be marked as REG_LIVE_READ but this does not happen: - fp[-8] in a current state is already marked as REG_LIVE_WRITTEN; - fp[-8].parent points to checkpoint.r1, parentage chain is used by mark_reg_read() to mark checkpoint states. At (10) the verification is finished for path 1-10 and jump 4-6 is examined. The checkpoint.fp[-8] never gets REG_LIVE_READ mark and this spill is pruned from the cached states by clean_live_states(). Hence verifier state obtained via path 1-4,6 is deemed identical to one obtained via path 1-6 and program marked as safe. Note: the example should be executed with BPF_F_TEST_STATE_FREQ flag set to force creation of intermediate verifier states. This commit revisits the locations where bpf_reg_state instances are copied and replaces the direct copies with a call to a function copy_register_state(dst, src) that preserves 'parent' and 'live' fields of the 'dst'. Fixes: 679c782de14b ("bpf/verifier: per-register parent pointers") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230106142214.1040390-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09bpf: Fix a possible task gone issue with bpf_send_signal[_thread]() helpersYonghong Song1-1/+2
[ Upstream commit bdb7fdb0aca8b96cef9995d3a57e251c2289322f ] In current bpf_send_signal() and bpf_send_signal_thread() helper implementation, irq_work is used to handle nmi context. Hao Sun reported in [1] that the current task at the entry of the helper might be gone during irq_work callback processing. To fix the issue, a reference is acquired for the current task before enqueuing into the irq_work so that the queued task is still available during irq_work callback processing. [1] https://lore.kernel.org/bpf/20230109074425.12556-1-sunhao.th@gmail.com/ Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper") Tested-by: Hao Sun <sunhao.th@gmail.com> Reported-by: Hao Sun <sunhao.th@gmail.com> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230118204815.3331855-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-09bpf: Fix off-by-one error in bpf_mem_cache_idx()Hou Tao1-1/+1
[ Upstream commit 36024d023d139a0c8b552dc3b7f4dc7b4c139e8f ] According to the definition of sizes[NUM_CACHES], when the size passed to bpf_mem_cache_size() is 256, it should return 6 instead 7. Fixes: 7c8199e24fa0 ("bpf: Introduce any context BPF specific memory allocator.") Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230118084630.3750680-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-06bpf: Skip task with pid=1 in send_signal_common()Hao Sun1-0/+3
[ Upstream commit a3d81bc1eaef48e34dd0b9b48eefed9e02a06451 ] The following kernel panic can be triggered when a task with pid=1 attaches a prog that attempts to send killing signal to itself, also see [1] for more details: Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b CPU: 3 PID: 1 Comm: systemd Not tainted 6.1.0-09652-g59fe41b5255f #148 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x100/0x178 lib/dump_stack.c:106 panic+0x2c4/0x60f kernel/panic.c:275 do_exit.cold+0x63/0xe4 kernel/exit.c:789 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x2460/0x2600 kernel/signal.c:2858 arch_do_signal_or_restart+0x78/0x5d0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd So skip task with pid=1 in bpf_send_signal_common() to avoid the panic. [1] https://lore.kernel.org/bpf/20221222043507.33037-1-sunhao.th@gmail.com Signed-off-by: Hao Sun <sunhao.th@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230106084838.12690-1-sunhao.th@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01tracing/osnoise: Use built-in RCU list checkingChuang Wang1-3/+2
[ Upstream commit 685b64e4d6da4be8b4595654a57db663b3d1dfc2 ] list_for_each_entry_rcu() has built-in RCU and lock checking. Pass cond argument to list_for_each_entry_rcu() to silence false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled. Execute as follow: [tracing]# echo osnoise > current_tracer [tracing]# echo 1 > tracing_on [tracing]# echo 0 > tracing_on The trace_types_lock is held when osnoise_tracer_stop() or timerlat_tracer_stop() are called in the non-RCU read side section. So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep warning. Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr") Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01trace_events_hist: add check for return value of 'create_hist_field'Natalia Petrova1-0/+2
commit 8b152e9150d07a885f95e1fd401fc81af202d9a4 upstream. Function 'create_hist_field' is called recursively at trace_events_hist.c:1954 and can return NULL-value that's why we have to check it to avoid null pointer dereference. Found by Linux Verification Center (linuxtesting.org) with SVACE. Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru Cc: stable@vger.kernel.org Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers") Signed-off-by: Natalia Petrova <n.petrova@fintech.ru> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01tracing: Make sure trace_printk() can output as soon as it can be usedSteven Rostedt (Google)3-2/+4
commit 3bb06eb6e9acf7c4a3e1b5bc87aed398ff8e2253 upstream. Currently trace_printk() can be used as soon as early_trace_init() is called from start_kernel(). But if a crash happens, and "ftrace_dump_on_oops" is set on the kernel command line, all you get will be: [ 0.456075] <idle>-0 0dN.2. 347519us : Unknown type 6 [ 0.456075] <idle>-0 0dN.2. 353141us : Unknown type 6 [ 0.456075] <idle>-0 0dN.2. 358684us : Unknown type 6 This is because the trace_printk() event (type 6) hasn't been registered yet. That gets done via an early_initcall(), which may be early, but not early enough. Instead of registering the trace_printk() event (and other ftrace events, which are not trace events) via an early_initcall(), have them registered at the same time that trace_printk() can be used. This way, if there is a crash before early_initcall(), then the trace_printk()s will actually be useful. Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: e725c731e3bb1 ("tracing: Split tracing initialization into two for early initialization") Reported-by: "Joel Fernandes (Google)" <joel@joelfernandes.org> Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01ftrace: Export ftrace_free_filter() to modulesMark Rutland1-1/+22
commit 8be9fbd5345da52f4a74f7f81d55ff9fa0a2958e upstream. Setting filters on an ftrace ops results in some memory being allocated for the filter hashes, which must be freed before the ops can be freed. This can be done by removing every individual element of the hash by calling ftrace_set_filter_ip() or ftrace_set_filter_ips() with `remove` set, but this is somewhat error prone as it's easy to forget to remove an element. Make it easier to clean this up by exporting ftrace_free_filter(), which can be used to clean up all of the filter hashes after an ftrace_ops has been unregistered. Using this, fix the ftrace-direct* samples to free hashes prior to being unloaded. All other code either removes individual filters explicitly or is built-in and already calls ftrace_free_filter(). Link: https://lkml.kernel.org/r/20230103124912.2948963-3-mark.rutland@arm.com Cc: stable@vger.kernel.org Cc: Florent Revest <revest@chromium.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface") Fixes: 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01module: Don't wait for GOING modulesPetr Pavlu1-5/+21
commit 0254127ab977e70798707a7a2b757c9f3c971210 upstream. During a system boot, it can happen that the kernel receives a burst of requests to insert the same module but loading it eventually fails during its init call. For instance, udev can make a request to insert a frequency module for each individual CPU when another frequency module is already loaded which causes the init function of the new module to return an error. Since commit 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading"), the kernel waits for modules in MODULE_STATE_GOING state to finish unloading before making another attempt to load the same module. This creates unnecessary work in the described scenario and delays the boot. In the worst case, it can prevent udev from loading drivers for other devices and might cause timeouts of services waiting on them and subsequently a failed boot. This patch attempts a different solution for the problem 6e6de3dee51a was trying to solve. Rather than waiting for the unloading to complete, it returns a different error code (-EBUSY) for modules in the GOING state. This should avoid the error situation that was described in 6e6de3dee51a (user space attempting to load a dependent module because the -EEXIST error code would suggest to user space that the first module had been loaded successfully), while avoiding the delay situation too. This has been tested on linux-next since December 2022 and passes all kmod selftests except test 0009 with module compression enabled but it has been confirmed that this issue has existed and has gone unnoticed since prior to this commit and can also be reproduced without module compression with a simple usleep(5000000) on tools/modprobe.c [0]. These failures are caused by hitting the kernel mod_concurrent_max and can happen either due to a self inflicted kernel module auto-loead DoS somehow or on a system with large CPU count and each CPU count incorrectly triggering many module auto-loads. Both of those issues need to be fixed in-kernel. [0] https://lore.kernel.org/all/Y9A4fiobL6IHp%2F%2FP@bombadil.infradead.org/ Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading") Co-developed-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Petr Mladek <pmladek@suse.com> [mcgrof: enhance commit log with testing and kmod test result interpretation ] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01sched/uclamp: Fix a uninitialized variable warningsQais Yousef1-19/+16
[ Upstream commit e26fd28db82899be71b4b949527373d0a6be1e65 ] Addresses the following warnings: > config: riscv-randconfig-m031-20221111 > compiler: riscv64-linux-gcc (GCC) 12.1.0 > > smatch warnings: > kernel/sched/fair.c:7263 find_energy_efficient_cpu() error: uninitialized symbol 'util_min'. > kernel/sched/fair.c:7263 find_energy_efficient_cpu() error: uninitialized symbol 'util_max'. Fixes: 244226035a1f ("sched/uclamp: Fix fits_capacity() check in feec()") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230112122708.330667-2-qyousef@layalina.io Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01sched/fair: Check if prev_cpu has highest spare cap in feec()Pierre Gondois1-6/+7
[ Upstream commit ad841e569f5c88e3332b32a000f251f33ff32187 ] When evaluating the CPU candidates in the perf domain (pd) containing the previously used CPU (prev_cpu), find_energy_efficient_cpu() evaluates the energy of the pd: - without the task (base_energy) - with the task placed on prev_cpu (if the task fits) - with the task placed on the CPU with the highest spare capacity, prev_cpu being excluded from this set If prev_cpu is already the CPU with the highest spare capacity, max_spare_cap_cpu will be the CPU with the second highest spare capacity. On an Arm64 Juno-r2, with a workload of 10 tasks at a 10% duty cycle, when prev_cpu and max_spare_cap_cpu are both valid candidates, prev_spare_cap > max_spare_cap at ~82%. Thus the energy of the pd when placing the task on max_spare_cap_cpu is computed with no possible positive outcome 82% most of the time. Do not consider max_spare_cap_cpu as a valid candidate if prev_spare_cap > max_spare_cap. Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20221006081052.3862167-2-pierre.gondois@arm.com Stable-dep-of: e26fd28db828 ("sched/uclamp: Fix a uninitialized variable warnings") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01kcsan: test: don't put the expect array on the stackMax Filippov1-1/+6
[ Upstream commit 5b24ac2dfd3eb3e36f794af3aa7f2828b19035bd ] Size of the 'expect' array in the __report_matches is 1536 bytes, which is exactly the default frame size warning limit of the xtensa architecture. As a result allmodconfig xtensa kernel builds with the gcc that does not support the compiler plugins (which otherwise would push the said warning limit to 2K) fail with the following message: kernel/kcsan/kcsan_test.c:257:1: error: the frame size of 1680 bytes is larger than 1536 bytes Fix it by dynamically allocating the 'expect' array. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Reviewed-by: Marco Elver <elver@google.com> Tested-by: Marco Elver <elver@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01bpf: Fix pointer-leak due to insufficient speculative store bypass mitigationLuis Gerhorst1-1/+3
[ Upstream commit e4f4db47794c9f474b184ee1418f42e6a07412b6 ] To mitigate Spectre v4, 2039f26f3aca ("bpf: Fix leakage due to insufficient speculative store bypass mitigation") inserts lfence instructions after 1) initializing a stack slot and 2) spilling a pointer to the stack. However, this does not cover cases where a stack slot is first initialized with a pointer (subject to sanitization) but then overwritten with a scalar (not subject to sanitization because the slot was already initialized). In this case, the second write may be subject to speculative store bypass (SSB) creating a speculative pointer-as-scalar type confusion. This allows the program to subsequently leak the numerical pointer value using, for example, a branch-based cache side channel. To fix this, also sanitize scalars if they write a stack slot that previously contained a pointer. Assuming that pointer-spills are only generated by LLVM on register-pressure, the performance impact on most real-world BPF programs should be small. The following unprivileged BPF bytecode drafts a minimal exploit and the mitigation: [...] // r6 = 0 or 1 (skalar, unknown user input) // r7 = accessible ptr for side channel // r10 = frame pointer (fp), to be leaked // r9 = r10 # fp alias to encourage ssb *(u64 *)(r9 - 8) = r10 // fp[-8] = ptr, to be leaked // lfence added here because of pointer spill to stack. // // Ommitted: Dummy bpf_ringbuf_output() here to train alias predictor // for no r9-r10 dependency. // *(u64 *)(r10 - 8) = r6 // fp[-8] = scalar, overwrites ptr // 2039f26f3aca: no lfence added because stack slot was not STACK_INVALID, // store may be subject to SSB // // fix: also add an lfence when the slot contained a ptr // r8 = *(u64 *)(r9 - 8) // r8 = architecturally a scalar, speculatively a ptr // // leak ptr using branch-based cache side channel: r8 &= 1 // choose bit to leak if r8 == 0 goto SLOW // no mispredict // architecturally dead code if input r6 is 0, // only executes speculatively iff ptr bit is 1 r8 = *(u64 *)(r7 + 0) # encode bit in cache (0: slow, 1: fast) SLOW: [...] After running this, the program can time the access to *(r7 + 0) to determine whether the chosen pointer bit was 0 or 1. Repeat this 64 times to recover the whole address on amd64. In summary, sanitization can only be skipped if one scalar is overwritten with another scalar. Scalar-confusion due to speculative store bypass can not lead to invalid accesses because the pointer bounds deducted during verification are enforced using branchless logic. See 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") for details. Do not make the mitigation depend on !env->allow_{uninit_stack,ptr_leaks} because speculative leaks are likely unexpected if these were enabled. For example, leaking the address to a protected log file may be acceptable while disabling the mitigation might unintentionally leak the address into the cached-state of a map that is accessible to unprivileged processes. Fixes: 2039f26f3aca ("bpf: Fix leakage due to insufficient speculative store bypass mitigation") Signed-off-by: Luis Gerhorst <gerhorst@cs.fau.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Henriette Hofmeier <henriette.hofmeier@rub.de> Link: https://lore.kernel.org/bpf/edc95bad-aada-9cfc-ffe2-fa9bb206583c@cs.fau.de Link: https://lore.kernel.org/bpf/20230109150544.41465-1-gerhorst@cs.fau.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01bpf: hash map, avoid deadlock with suitable hash maskTonghao Zhang1-2/+2
[ Upstream commit 9f907439dc80e4a2fcfb949927b36c036468dbb3 ] The deadlock still may occur while accessed in NMI and non-NMI context. Because in NMI, we still may access the same bucket but with different map_locked index. For example, on the same CPU, .max_entries = 2, we update the hash map, with key = 4, while running bpf prog in NMI nmi_handle(), to update hash map with key = 20, so it will have the same bucket index but have different map_locked index. To fix this issue, using min mask to hash again. Fixes: 20b6cc34ea74 ("bpf: Avoid hashtab deadlock with map_locked") Signed-off-by: Tonghao Zhang <tong@infragraf.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Hou Tao <houtao1@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230111092903.92389-1-tong@infragraf.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-24exit: Use READ_ONCE() for all oops/warn limit readsKees Cook2-4/+9
commit 7535b832c6399b5ebfc5b53af5c51dd915ee2538 upstream. Use a temporary variable to take full advantage of READ_ONCE() behavior. Without this, the report (and even the test) might be out of sync with the initial test. Reported-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/lkml/Y5x7GXeluFmZ8E0E@hirez.programming.kicks-ass.net Fixes: 9fc9e278a5c0 ("panic: Introduce warn_limit") Fixes: d4ccd54d28d3 ("exit: Put an upper limit on how often we can oops") Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jann Horn <jannh@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Marco Elver <elver@google.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24panic: Expose "warn_count" to sysfsKees Cook1-2/+20
commit 8b05aa26336113c4cea25f1c333ee8cd4fc212a6 upstream. Since Warn count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/warn_count to expose it to userspace. Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24panic: Introduce warn_limitKees Cook1-0/+14
commit 9fc9e278a5c0b708eeffaf47d6eb0c82aa74ed78 upstream. Like oops_limit, add warn_limit for limiting the number of warnings when panic_on_warn is not set. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Petr Mladek <pmladek@suse.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24panic: Consolidate open-coded panic_on_warn checksKees Cook3-6/+9
commit 79cc1ba7badf9e7a12af99695a557e9ce27ee967 upstream. Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll their own warnings, and each check "panic_on_warn". Consolidate this into a single function so that future instrumentation can be added in a single location. Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Gow <davidgow@google.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: Jann Horn <jannh@google.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24exit: Allow oops_limit to be disabledKees Cook1-1/+1
commit de92f65719cd672f4b48397540b9f9eff67eca40 upstream. In preparation for keeping oops_limit logic in sync with warn_limit, have oops_limit == 0 disable checking the Oops counter. Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-doc@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24exit: Expose "oops_count" to sysfsKees Cook1-2/+20
commit 9db89b41117024f80b38b15954017fb293133364 upstream. Since Oops count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/oops_count to expose it to userspace. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jann Horn <jannh@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24exit: Put an upper limit on how often we can oopsJann Horn1-0/+42
commit d4ccd54d28d3c8598e2354acc13e28c060961dbb upstream. Many Linux systems are configured to not panic on oops; but allowing an attacker to oops the system **really** often can make even bugs that look completely unexploitable exploitable (like NULL dereferences and such) if each crash elevates a refcount by one or a lock is taken in read mode, and this causes a counter to eventually overflow. The most interesting counters for this are 32 bits wide (like open-coded refcounts that don't use refcount_t). (The ldsem reader count on 32-bit platforms is just 16 bits, but probably nobody cares about 32-bit platforms that much nowadays.) So let's panic the system if the kernel is constantly oopsing. The speed of oopsing 2^32 times probably depends on several factors, like how long the stack trace is and which unwinder you're using; an empirically important one is whether your console is showing a graphical environment or a text console that oopses will be printed to. In a quick single-threaded benchmark, it looks like oopsing in a vfork() child with a very short stack trace only takes ~510 microseconds per run when a graphical console is active; but switching to a text console that oopses are printed to slows it down around 87x, to ~45 milliseconds per run. (Adding more threads makes this faster, but the actual oops printing happens under &die_lock on x86, so you can maybe speed this up by a factor of around 2 and then any further improvement gets eaten up by lock contention.) It looks like it would take around 8-12 days to overflow a 32-bit counter with repeated oopsing on a multi-core X86 system running a graphical environment; both me (in an X86 VM) and Seth (with a distro kernel on normal hardware in a standard configuration) got numbers in that ballpark. 12 days aren't *that* short on a desktop system, and you'd likely need much longer on a typical server system (assuming that people don't run graphical desktop environments on their servers), and this is a *very* noisy and violent approach to exploiting the kernel; and it also seems to take orders of magnitude longer on some machines, probably because stuff like EFI pstore will slow it down a ton if that's active. Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24panic: Separate sysctl logic from CONFIG_SMPKees Cook1-1/+3
commit 9360d035a579d95d1e76c471061b9065b18a0eb1 upstream. In preparation for adding more sysctls directly in kernel/panic.c, split CONFIG_SMP from the logic that adds sysctls. Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and ↵Paul Moore2-7/+2
PERF_BPF_EVENT_PROG_UNLOAD commit ef01f4e25c1760920e2c94f1c232350277ace69b upstream. When changing the ebpf program put() routines to support being called from within IRQ context the program ID was reset to zero prior to calling the perf event and audit UNLOAD record generators, which resulted in problems as the ebpf program ID was bogus (always zero). This patch addresses this problem by removing an unnecessary call to bpf_prog_free_id() in __bpf_prog_offload_destroy() and adjusting __bpf_prog_put() to only call bpf_prog_free_id() after audit and perf have finished their bpf program unload tasks in bpf_prog_put_deferred(). For the record, no one can determine, or remember, why it was necessary to free the program ID, and remove it from the IDR, prior to executing bpf_prog_put_deferred(); regardless, both Stanislav and Alexei agree that the approach in this patch should be safe. It is worth noting that when moving the bpf_prog_free_id() call, the do_idr_lock parameter was forced to true as the ebpf devs determined this was the correct as the do_idr_lock should always be true. The do_idr_lock parameter will be removed in a follow-up patch, but it was kept here to keep the patch small in an effort to ease any stable backports. I also modified the bpf_audit_prog() logic used to associate the AUDIT_BPF record with other associated records, e.g. @ctx != NULL. Instead of keying off the operation, it now keys off the execution context, e.g. '!in_irg && !irqs_disabled()', which is much more appropriate and should help better connect the UNLOAD operations with the associated audit state (other audit records). Cc: stable@vger.kernel.org Fixes: d809e134be7a ("bpf: Prepare bpf_prog_put() to be called from irq context.") Reported-by: Burn Alting <burn.alting@iinet.net.au> Reported-by: Jiri Olsa <olsajiri@gmail.com> Suggested-by: Stanislav Fomichev <sdf@google.com> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230106154400.74211-1-paul@paul-moore.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24prlimit: do_prlimit needs to have a speculation checkGreg Kroah-Hartman1-0/+2
commit 739790605705ddcf18f21782b9c99ad7d53a8c11 upstream. do_prlimit() adds the user-controlled resource value to a pointer that will subsequently be dereferenced. In order to help prevent this codepath from being used as a spectre "gadget" a barrier needs to be added after checking the range. Reported-by: Jordy Zomer <jordyzomer@google.com> Tested-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24bpf: keep a reference to the mm, in case the task is dead.Kui-Feng Lee1-12/+27
[ Upstream commit 7ff94f276f8ea05df82eb115225e9b26f47a3347 ] Fix the system crash that happens when a task iterator travel through vma of tasks. In task iterators, we used to access mm by following the pointer on the task_struct; however, the death of a task will clear the pointer, even though we still hold the task_struct. That can cause an unexpected crash for a null pointer when an iterator is visiting a task that dies during the visit. Keeping a reference of mm on the iterator ensures we always have a valid pointer to mm. Co-developed-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Reported-by: Nathan Slingerland <slinger@meta.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221216221855.4122288-2-kuifeng@meta.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18sched/core: Fix arch_scale_freq_tick() on tickless systemsYair Podemsky1-1/+3
[ Upstream commit 7fb3ff22ad8772bbf0e3ce1ef3eb7b09f431807f ] In order for the scheduler to be frequency invariant we measure the ratio between the maximum CPU frequency and the actual CPU frequency. During long tickless periods of time the calculations that keep track of that might overflow, in the function scale_freq_tick(): if (check_shl_overflow(acnt, 2*SCHED_CAPACITY_SHIFT, &acnt)) goto error; eventually forcing the kernel to disable the feature for all CPUs, and show the warning message: "Scheduler frequency invariance went wobbly, disabling!". Let's avoid that by limiting the frequency invariant calculations to CPUs with regular tick. Fixes: e2b0d619b400 ("x86, sched: check for counters overflow in frequency invariant accounting") Suggested-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> Signed-off-by: Yair Podemsky <ypodemsk@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Acked-by: Giovanni Gherdovich <ggherdovich@suse.cz> Link: https://lore.kernel.org/r/20221130125121.34407-1-ypodemsk@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18sched/core: Fix use-after-free bug in dup_user_cpus_ptr()Waiman Long1-4/+33
commit 87ca4f9efbd7cc649ff43b87970888f2812945b8 upstream. Since commit 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems"), the setting and clearing of user_cpus_ptr are done under pi_lock for arm64 architecture. However, dup_user_cpus_ptr() accesses user_cpus_ptr without any lock protection. Since sched_setaffinity() can be invoked from another process, the process being modified may be undergoing fork() at the same time. When racing with the clearing of user_cpus_ptr in __set_cpus_allowed_ptr_locked(), it can lead to user-after-free and possibly double-free in arm64 kernel. Commit 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") fixes this problem as user_cpus_ptr, once set, will never be cleared in a task's lifetime. However, this bug was re-introduced in commit 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in do_set_cpus_allowed(). This time, it will affect all arches. Fix this bug by always clearing the user_cpus_ptr of the newly cloned/forked task before the copying process starts and check the user_cpus_ptr state of the source task under pi_lock. Note to stable, this patch won't be applicable to stable releases. Just copy the new dup_user_cpus_ptr() function over. Fixes: 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems") Fixes: 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") Reported-by: David Wang 王标 <wangbiao3@xiaomi.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221231041120.440785-2-longman@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-12bpf: Fix panic due to wrong pageattr of im->imageChuang Wang1-0/+4
commit 9ed1d9aeef5842ecacb660fce933613b58af1e00 upstream. In the scenario where livepatch and kretfunc coexist, the pageattr of im->image is rox after arch_prepare_bpf_trampoline in bpf_trampoline_update, and then modify_fentry or register_fentry returns -EAGAIN from bpf_tramp_ftrace_ops_func, the BPF_TRAMP_F_ORIG_STACK flag will be configured, and arch_prepare_bpf_trampoline will be re-executed. At this time, because the pageattr of im->image is rox, arch_prepare_bpf_trampoline will read and write im->image, which causes a fault. as follows: insmod livepatch-sample.ko # samples/livepatch/livepatch-sample.c bpftrace -e 'kretfunc:cmdline_proc_show {}' BUG: unable to handle page fault for address: ffffffffa0206000 PGD 322d067 P4D 322d067 PUD 322e063 PMD 1297e067 PTE d428061 Oops: 0003 [#1] PREEMPT SMP PTI CPU: 2 PID: 270 Comm: bpftrace Tainted: G E K 6.1.0 #5 RIP: 0010:arch_prepare_bpf_trampoline+0xed/0x8c0 RSP: 0018:ffffc90001083ad8 EFLAGS: 00010202 RAX: ffffffffa0206000 RBX: 0000000000000020 RCX: 0000000000000000 RDX: ffffffffa0206001 RSI: ffffffffa0206000 RDI: 0000000000000030 RBP: ffffc90001083b70 R08: 0000000000000066 R09: ffff88800f51b400 R10: 000000002e72c6e5 R11: 00000000d0a15080 R12: ffff8880110a68c8 R13: 0000000000000000 R14: ffff88800f51b400 R15: ffffffff814fec10 FS: 00007f87bc0dc780(0000) GS:ffff88803e600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa0206000 CR3: 0000000010b70000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> bpf_trampoline_update+0x25a/0x6b0 __bpf_trampoline_link_prog+0x101/0x240 bpf_trampoline_link_prog+0x2d/0x50 bpf_tracing_prog_attach+0x24c/0x530 bpf_raw_tp_link_attach+0x73/0x1d0 __sys_bpf+0x100e/0x2570 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x5b/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd With this patch, when modify_fentry or register_fentry returns -EAGAIN from bpf_tramp_ftrace_ops_func, the pageattr of im->image will be reset to nx+rw. Cc: stable@vger.kernel.org Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)") Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20221224133146.780578-1-nashuiliang@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-12bpf: Always use maximal size for copy_array()Kees Cook1-5/+7
[ Upstream commit 45435d8da71f9f3e6860e6e6ea9667b6ec17ec64 ] Instead of counting on prior allocations to have sized allocations to the next kmalloc bucket size, always perform a krealloc that is at least ksize(dst) in size (which is a no-op), so the size can be correctly tracked by all the various allocation size trackers (KASAN, __alloc_size, etc). Reported-by: Hyunwoo Kim <v4bel@theori.io> Link: https://lore.kernel.org/bpf/20221223094551.GA1439509@ubuntu Fixes: ceb35b666d42 ("bpf/verifier: Use kmalloc_size_roundup() to match ksize() usage") Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: bpf@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221223182836.never.866-kees@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-07tracing: Fix infinite loop in tracing_read_pipe on overflowed print_trace_lineYang Jihong1-1/+14
commit c1ac03af6ed45d05786c219d102f37eb44880f28 upstream. print_trace_line may overflow seq_file buffer. If the event is not consumed, the while loop keeps peeking this event, causing a infinite loop. Link: https://lkml.kernel.org/r/20221129113009.182425-1-yangjihong1@huawei.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Fixes: 088b1e427dbba ("ftrace: pipe fixes") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07tracing: Fix issue of missing one synthetic fieldZheng Yejian1-1/+1
commit ff4837f7fe59ff018eca4705a70eca5e0b486b97 upstream. The maximum number of synthetic fields supported is defined as SYNTH_FIELDS_MAX which value currently is 64, but it actually fails when try to generate a synthetic event with 64 fields by executing like: # echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\ int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\ int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\ int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\ int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\ int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\ int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\ int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\ int v63; int v64" >> /sys/kernel/tracing/synthetic_events Correct the field counting to fix it. Link: https://lore.kernel.org/linux-trace-kernel/20221207091557.3137904-1-zhengyejian1@huawei.com Cc: <mhiramat@kernel.org> Cc: <zanussi@kernel.org> Cc: stable@vger.kernel.org Fixes: c9e759b1e845 ("tracing: Rework synthetic event command parsing") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07tracing/probes: Handle system names with hyphensSteven Rostedt (Google)2-4/+17
commit 575b76cb885532aae13a9d979fd476bb2b156cb9 upstream. When creating probe names, a check is done to make sure it matches basic C standard variable naming standards. Basically, starts with alphabetic or underline, and then the rest of the characters have alpha-numeric or underline in them. But system names do not have any true naming conventions, as they are created by the TRACE_SYSTEM macro and nothing tests to see what they are. The "xhci-hcd" trace events has a '-' in the system name. When trying to attach a eprobe to one of these trace points, it fails because the system name does not follow the variable naming convention because of the hyphen, and the eprobe checks fail on this. Allow hyphens in the system name so that eprobes can attach to the "xhci-hcd" trace events. Link: https://lore.kernel.org/all/Y3eJ8GiGnEvVd8%2FN@macondo/ Link: https://lore.kernel.org/linux-trace-kernel/20221122122345.160f5077@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Fixes: 5b7a96220900e ("tracing/probe: Check event/group naming rule at parsing") Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07tracing/hist: Fix wrong return value in parse_action_params()Zheng Yejian1-0/+1
commit 2cc6a528882d0e0ccbc1bca5f95b8c963cedac54 upstream. When number of synth fields is more than SYNTH_FIELDS_MAX, parse_action_params() should return -EINVAL. Link: https://lore.kernel.org/linux-trace-kernel/20221207034635.2253990-1-zhengyejian1@huawei.com Cc: <mhiramat@kernel.org> Cc: <zanussi@kernel.org> Cc: stable@vger.kernel.org Fixes: c282a386a397 ("tracing: Add 'onmatch' hist trigger action support") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07tracing: Fix complicated dependency of CONFIG_TRACER_MAX_TRACEMasami Hiramatsu (Google)3-15/+18
commit e25e43a4e5d8cb2323553d8b6a7ba08d2ebab21f upstream. Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the CONFIG_TRACER_MAX_TRACE code, but that is complicated and has introduced a bug; It declares tracing_max_lat_fops data structure outside of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that declaration comes to a definition(!). To fix this issue, and do not repeat the similar problem, makes CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the CONFIG_TRACER_MAX_TRACE always. It has there benefits; - Fix the tracing_max_lat_fops bug - Simplify the #ifdefs - CONFIG_TRACER_MAX_TRACE code is fully enabled, or not. Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3 Fixes: 424b650f35c7 ("tracing: Fix missing osnoise tracer on max_latency") Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: stable@vger.kernel.org Reported-by: David Howells <dhowells@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ (original thread and v1) Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@intel.com/T/#u (v1 error report) Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07tracing: Fix race where eprobes can be called before the eventSteven Rostedt (Google)1-0/+3
commit d5f30a7da8ea8e6450250275cec5670cee3c4264 upstream. The flag that tells the event to call its triggers after reading the event is set for eprobes after the eprobe is enabled. This leads to a race where the eprobe may be triggered at the beginning of the event where the record information is NULL. The eprobe then dereferences the NULL record causing a NULL kernel pointer bug. Test for a NULL record to keep this from happening. Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/ Link: https://lore.kernel.org/all/20221117214249.2addbe10@gandalf.local.home/ Cc: stable@vger.kernel.org Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-13 00:42:28 +0300