December 2023 - Linux-stable-mirror

[for-linus][PATCH 4/8] tracing: Fix incomplete locking when disabling buffered events

by Steven Rostedt

From: Petr Pavlu <petr.pavlu(a)suse.com> The following warning appears when using buffered events: [ 203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420 [...] [ 203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G E 6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a [ 203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017 [ 203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420 [ 203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff [ 203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202 [ 203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000 [ 203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400 [ 203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000 [ 203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008 [ 203.781846] FS: 00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000 [ 203.781851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0 [ 203.781862] Call Trace: [ 203.781870] <TASK> [ 203.851949] trace_event_buffer_commit+0x1ea/0x250 [ 203.851967] trace_event_raw_event_sys_enter+0x83/0xe0 [ 203.851983] syscall_trace_enter.isra.0+0x182/0x1a0 [ 203.851990] do_syscall_64+0x3a/0xe0 [ 203.852075] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 203.852090] RIP: 0033:0x7f4cd870fa77 [ 203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48 [ 203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089 [ 203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77 [ 203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0 [ 203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0 [ 203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40 [ 204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0 [ 204.049256] </TASK> For instance, it can be triggered by running these two commands in parallel: $ while true; do echo hist:key=id.syscall:val=hitcount > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger; done $ stress-ng --sysinfo $(nproc) The warning indicates that the current ring_buffer_per_cpu is not in the committing state. It happens because the active ring_buffer_event doesn't actually come from the ring_buffer_per_cpu but is allocated from trace_buffered_event. The bug is in function trace_buffered_event_disable() where the following normally happens: * The code invokes disable_trace_buffered_event() via smp_call_function_many() and follows it by synchronize_rcu(). This increments the per-CPU variable trace_buffered_event_cnt on each target CPU and grants trace_buffered_event_disable() the exclusive access to the per-CPU variable trace_buffered_event. * Maintenance is performed on trace_buffered_event, all per-CPU event buffers get freed. * The code invokes enable_trace_buffered_event() via smp_call_function_many(). This decrements trace_buffered_event_cnt and releases the access to trace_buffered_event. A problem is that smp_call_function_many() runs a given function on all target CPUs except on the current one. The following can then occur: * Task X executing trace_buffered_event_disable() runs on CPU 0. * The control reaches synchronize_rcu() and the task gets rescheduled on another CPU 1. * The RCU synchronization finishes. At this point, trace_buffered_event_disable() has the exclusive access to all trace_buffered_event variables except trace_buffered_event[CPU0] because trace_buffered_event_cnt[CPU0] is never incremented and if the buffer is currently unused, remains set to 0. * A different task Y is scheduled on CPU 0 and hits a trace event. The code in trace_event_buffer_lock_reserve() sees that trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the buffer provided by trace_buffered_event[CPU0]. * Task X continues its execution in trace_buffered_event_disable(). The code incorrectly frees the event buffer pointed by trace_buffered_event[CPU0] and resets the variable to NULL. * Task Y writes event data to the now freed buffer and later detects the created inconsistency. The issue is observable since commit dea499781a11 ("tracing: Fix warning in trace_buffered_event_disable()") which moved the call of trace_buffered_event_disable() in __ftrace_event_enable_disable() earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..). The underlying problem in trace_buffered_event_disable() is however present since the original implementation in commit 0fc1b09ff1ff ("tracing: Use temp buffer when filtering events"). Fix the problem by replacing the two smp_call_function_many() calls with on_each_cpu_mask() which invokes a given callback on all CPUs. Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/ Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com Cc: stable(a)vger.kernel.org Fixes: 0fc1b09ff1ff ("tracing: Use temp buffer when filtering events") Fixes: dea499781a11 ("tracing: Fix warning in trace_buffered_event_disable()") Signed-off-by: Petr Pavlu <petr.pavlu(a)suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2492c6c76850..6aeffa4a6994 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2781,11 +2781,9 @@ void trace_buffered_event_disable(void) if (--trace_buffered_event_ref) return; - preempt_disable(); /* For each CPU, set the buffer as used. */ - smp_call_function_many(tracing_buffer_mask, - disable_trace_buffered_event, NULL, 1); - preempt_enable(); + on_each_cpu_mask(tracing_buffer_mask, disable_trace_buffered_event, + NULL, true); /* Wait for all current users to finish */ synchronize_rcu(); @@ -2800,11 +2798,9 @@ void trace_buffered_event_disable(void) */ smp_wmb(); - preempt_disable(); /* Do the work on each cpu */ - smp_call_function_many(tracing_buffer_mask, - enable_trace_buffered_event, NULL, 1); - preempt_enable(); + on_each_cpu_mask(tracing_buffer_mask, enable_trace_buffered_event, NULL, + true); } static struct trace_buffer *temp_buffer; -- 2.42.0

10 months, 2 weeks

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[for-linus][PATCH 3/8] tracing: Disable snapshot buffer when stopping instance tracers

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> It use to be that only the top level instance had a snapshot buffer (for latency tracers like wakeup and irqsoff). When stopping a tracer in an instance would not disable the snapshot buffer. This could have some unintended consequences if the irqsoff tracer is enabled. Consolidate the tracing_start/stop() with tracing_start/stop_tr() so that all instances behave the same. The tracing_start/stop() functions will just call their respective tracing_start/stop_tr() with the global_array passed in. Link: https://lkml.kernel.org/r/20231205220011.041220035@goodmis.org Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 6d9b3fa5e7f6 ("tracing: Move tracing_max_latency into trace_array") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 110 +++++++++++++------------------------------ 1 file changed, 34 insertions(+), 76 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e978868b1a22..2492c6c76850 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2360,13 +2360,7 @@ int is_tracing_stopped(void) return global_trace.stop_count; } -/** - * tracing_start - quick start of the tracer - * - * If tracing is enabled but was stopped by tracing_stop, - * this will start the tracer back up. - */ -void tracing_start(void) +static void tracing_start_tr(struct trace_array *tr) { struct trace_buffer *buffer; unsigned long flags; @@ -2374,119 +2368,83 @@ void tracing_start(void) if (tracing_disabled) return; - raw_spin_lock_irqsave(&global_trace.start_lock, flags); - if (--global_trace.stop_count) { - if (global_trace.stop_count < 0) { + raw_spin_lock_irqsave(&tr->start_lock, flags); + if (--tr->stop_count) { + if (WARN_ON_ONCE(tr->stop_count < 0)) { /* Someone screwed up their debugging */ - WARN_ON_ONCE(1); - global_trace.stop_count = 0; + tr->stop_count = 0; } goto out; } /* Prevent the buffers from switching */ - arch_spin_lock(&global_trace.max_lock); + arch_spin_lock(&tr->max_lock); - buffer = global_trace.array_buffer.buffer; + buffer = tr->array_buffer.buffer; if (buffer) ring_buffer_record_enable(buffer); #ifdef CONFIG_TRACER_MAX_TRACE - buffer = global_trace.max_buffer.buffer; + buffer = tr->max_buffer.buffer; if (buffer) ring_buffer_record_enable(buffer); #endif - arch_spin_unlock(&global_trace.max_lock); - - out: - raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); -} - -static void tracing_start_tr(struct trace_array *tr) -{ - struct trace_buffer *buffer; - unsigned long flags; - - if (tracing_disabled) - return; - - /* If global, we need to also start the max tracer */ - if (tr->flags & TRACE_ARRAY_FL_GLOBAL) - return tracing_start(); - - raw_spin_lock_irqsave(&tr->start_lock, flags); - - if (--tr->stop_count) { - if (tr->stop_count < 0) { - /* Someone screwed up their debugging */ - WARN_ON_ONCE(1); - tr->stop_count = 0; - } - goto out; - } - - buffer = tr->array_buffer.buffer; - if (buffer) - ring_buffer_record_enable(buffer); + arch_spin_unlock(&tr->max_lock); out: raw_spin_unlock_irqrestore(&tr->start_lock, flags); } /** - * tracing_stop - quick stop of the tracer + * tracing_start - quick start of the tracer * - * Light weight way to stop tracing. Use in conjunction with - * tracing_start. + * If tracing is enabled but was stopped by tracing_stop, + * this will start the tracer back up. */ -void tracing_stop(void) +void tracing_start(void) + +{ + return tracing_start_tr(&global_trace); +} + +static void tracing_stop_tr(struct trace_array *tr) { struct trace_buffer *buffer; unsigned long flags; - raw_spin_lock_irqsave(&global_trace.start_lock, flags); - if (global_trace.stop_count++) + raw_spin_lock_irqsave(&tr->start_lock, flags); + if (tr->stop_count++) goto out; /* Prevent the buffers from switching */ - arch_spin_lock(&global_trace.max_lock); + arch_spin_lock(&tr->max_lock); - buffer = global_trace.array_buffer.buffer; + buffer = tr->array_buffer.buffer; if (buffer) ring_buffer_record_disable(buffer); #ifdef CONFIG_TRACER_MAX_TRACE - buffer = global_trace.max_buffer.buffer; + buffer = tr->max_buffer.buffer; if (buffer) ring_buffer_record_disable(buffer); #endif - arch_spin_unlock(&global_trace.max_lock); + arch_spin_unlock(&tr->max_lock); out: - raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); + raw_spin_unlock_irqrestore(&tr->start_lock, flags); } -static void tracing_stop_tr(struct trace_array *tr) +/** + * tracing_stop - quick stop of the tracer + * + * Light weight way to stop tracing. Use in conjunction with + * tracing_start. + */ +void tracing_stop(void) { - struct trace_buffer *buffer; - unsigned long flags; - - /* If global, we need to also stop the max tracer */ - if (tr->flags & TRACE_ARRAY_FL_GLOBAL) - return tracing_stop(); - - raw_spin_lock_irqsave(&tr->start_lock, flags); - if (tr->stop_count++) - goto out; - - buffer = tr->array_buffer.buffer; - if (buffer) - ring_buffer_record_disable(buffer); - - out: - raw_spin_unlock_irqrestore(&tr->start_lock, flags); + return tracing_stop_tr(&global_trace); } static int trace_save_cmdline(struct task_struct *tsk) -- 2.42.0

10 months, 2 weeks

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[for-linus][PATCH 2/8] tracing: Stop current tracer when resizing buffer

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> When the ring buffer is being resized, it can cause side effects to the running tracer. For instance, there's a race with irqsoff tracer that swaps individual per cpu buffers between the main buffer and the snapshot buffer. The resize operation modifies the main buffer and then the snapshot buffer. If a swap happens in between those two operations it will break the tracer. Simply stop the running tracer before resizing the buffers and enable it again when finished. Link: https://lkml.kernel.org/r/20231205220010.748996423@goodmis.org Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 3928a8a2d9808 ("ftrace: make work with new ring buffer") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 231c173ec04f..e978868b1a22 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6387,9 +6387,12 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, if (!tr->array_buffer.buffer) return 0; + /* Do not allow tracing while resizng ring buffer */ + tracing_stop_tr(tr); + ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu); if (ret < 0) - return ret; + goto out_start; #ifdef CONFIG_TRACER_MAX_TRACE if (!tr->current_trace->use_max_tr) @@ -6417,7 +6420,7 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, WARN_ON(1); tracing_disabled = 1; } - return ret; + goto out_start; } update_buffer_entries(&tr->max_buffer, cpu); @@ -6426,7 +6429,8 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, #endif /* CONFIG_TRACER_MAX_TRACE */ update_buffer_entries(&tr->array_buffer, cpu); - + out_start: + tracing_start_tr(tr); return ret; } -- 2.42.0

10 months, 2 weeks

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[for-linus][PATCH 1/8] tracing: Always update snapshot buffer size

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> It use to be that only the top level instance had a snapshot buffer (for latency tracers like wakeup and irqsoff). The update of the ring buffer size would check if the instance was the top level and if so, it would also update the snapshot buffer as it needs to be the same as the main buffer. Now that lower level instances also has a snapshot buffer, they too need to update their snapshot buffer sizes when the main buffer is changed, otherwise the following can be triggered: # cd /sys/kernel/tracing # echo 1500 > buffer_size_kb # mkdir instances/foo # echo irqsoff > instances/foo/current_tracer # echo 1000 > instances/foo/buffer_size_kb Produces: WARNING: CPU: 2 PID: 856 at kernel/trace/trace.c:1938 update_max_tr_single.part.0+0x27d/0x320 Which is: ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu); if (ret == -EBUSY) { [..] } WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); <== here That's because ring_buffer_swap_cpu() has: int ret = -EINVAL; [..] /* At least make sure the two buffers are somewhat the same */ if (cpu_buffer_a->nr_pages != cpu_buffer_b->nr_pages) goto out; [..] out: return ret; } Instead, update all instances' snapshot buffer sizes when their main buffer size is updated. Link: https://lkml.kernel.org/r/20231205220010.454662151@goodmis.org Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 6d9b3fa5e7f6 ("tracing: Move tracing_max_latency into trace_array") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9aebf904ff97..231c173ec04f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6392,8 +6392,7 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, return ret; #ifdef CONFIG_TRACER_MAX_TRACE - if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || - !tr->current_trace->use_max_tr) + if (!tr->current_trace->use_max_tr) goto out; ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); -- 2.42.0

10 months, 2 weeks

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patch "serial: ma35d1: Validate console index before assignment" added to tty-linus

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled serial: ma35d1: Validate console index before assignment to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. From f0b9d97a77fa8f18400450713358303a435ab688 Mon Sep 17 00:00:00 2001 From: Andi Shyti <andi.shyti(a)kernel.org> Date: Mon, 4 Dec 2023 17:38:03 +0100 Subject: serial: ma35d1: Validate console index before assignment The console is immediately assigned to the ma35d1 port without checking its index. This oversight can lead to out-of-bounds errors when the index falls outside the valid '0' to MA35_UART_NR range. Such scenario trigges ran error like the following: UBSAN: array-index-out-of-bounds in drivers/tty/serial/ma35d1_serial.c:555:51 index -1 is out of range for type 'uart_ma35d1_port [17] Check the index before using it and bail out with a warning. Fixes: 930cbf92db01 ("tty: serial: Add Nuvoton ma35d1 serial driver support") Signed-off-by: Andi Shyti <andi.shyti(a)kernel.org> Cc: Jacky Huang <ychuang3(a)nuvoton.com> Cc: <stable(a)vger.kernel.org> # v6.5+ Link: https://lore.kernel.org/r/20231204163804.1331415-2-andi.shyti@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/tty/serial/ma35d1_serial.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c index a6a7c405892e..21b574f78b86 100644 --- a/drivers/tty/serial/ma35d1_serial.c +++ b/drivers/tty/serial/ma35d1_serial.c @@ -552,11 +552,19 @@ static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char c */ static void ma35d1serial_console_write(struct console *co, const char *s, u32 count) { - struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index]; + struct uart_ma35d1_port *up; unsigned long flags; int locked = 1; u32 ier; + if ((co->index < 0) || (co->index >= MA35_UART_NR)) { + pr_warn("Failed to write on ononsole port %x, out of range\n", + co->index); + return; + } + + up = &ma35d1serial_ports[co->index]; + if (up->port.sysrq) locked = 0; else if (oops_in_progress) -- 2.43.0

10 months, 2 weeks

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[PATCH] irq: Resolve that mask_irq/unmask_irq may not be called in pairs

by xiongxin

When an interrupt controller uses a function such as handle_level_irq() as an interrupt handler and the controller implements the irq_disable() callback, the following scenario will appear in the i2c-hid driver in the sleep scenario: in the sleep flow, while the user is still triggering the i2c-hid interrupt, we get the following function call: handle_level_irq() -> mask_ack_irq() -> mask_irq() i2c_hid_core_suspend() -> disable_irq() -> __irq_disable() -> irq_state_set_disabled() -> irq_state_set_masked() irq_thread_fn() -> irq_finalize_oneshot() -> if (!desc->threads_oneshot && !irqd_irq_disabled() && irqd_irq_masked()) unmask_threaded_irq() -> unmask_irq() That is, when __irq_disable() is called between mask_irq() and irq_finalize_oneshot(), the code in irq_finalize_oneshot() will cause the !irqd_irq_disabled() fails to enter the unmask_irq() branch, which causes mask_irq/unmask_irq to be called unpaired and the i2c-hid interrupt to be masked. Since mask_irq/unmask_irq and irq_disabled() belong to two different hardware registers or policies, the !irqd_irq_disabled() assertion may not be used to determine whether unmask_irq() needs to be called. Cc: stable(a)vger.kernel.org Signed-off-by: xiongxin <xiongxin(a)kylinos.cn> Signed-off-by: Riwen Lu <luriwen(a)kylinos.cn> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 1782f90cd8c6..9160fc9170b3 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1120,8 +1120,7 @@ static void irq_finalize_oneshot(struct irq_desc *desc, desc->threads_oneshot &= ~action->thread_mask; - if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) && - irqd_irq_masked(&desc->irq_data)) + if (!desc->threads_oneshot && irqd_irq_masked(&desc->irq_data)) unmask_threaded_irq(desc); out_unlock: -- 2.34.1

10 months, 2 weeks

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Re: [PATCH] team: Fix use-after-free when an option instance allocation fails

by Florent Revest

On Wed, Dec 6, 2023 at 4:05 PM Hangbin Liu <liuhangbin(a)gmail.com> wrote: > > On Wed, Dec 06, 2023 at 01:37:18PM +0100, Florent Revest wrote: > > In __team_options_register, team_options are allocated and appended to > > the team's option_list. > > If one option instance allocation fails, the "inst_rollback" cleanup > > path frees the previously allocated options but doesn't remove them from > > the team's option_list. > > This leaves dangling pointers that can be dereferenced later by other > > parts of the team driver that iterate over options. > > > > This patch fixes the cleanup path to remove the dangling pointers from > > the list. > > > > As far as I can tell, this uaf doesn't have much security implications > > since it would be fairly hard to exploit (an attacker would need to make > > the allocation of that specific small object fail) but it's still nice > > to fix. > > > > Fixes: 80f7c6683fe0 ("team: add support for per-port options") > > Signed-off-by: Florent Revest <revest(a)chromium.org> > > Reviewed-by: Hangbin Liu <liuhangbin(a)gmail.com> Thank you for the quick reviews Hangbin & Jiri, I appreciate! :) I just realized I forgot to CC stable (like I always do... :) maybe I should tattoo it on my arm) Let me know if you'd like a v2 adding: Cc: stable(a)vger.kernel.org

10 months, 2 weeks

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[merged mm-hotfixes-stable] nilfs2-prevent-warning-in-nilfs_sufile_set_segment_usage.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: nilfs2: prevent WARNING in nilfs_sufile_set_segment_usage() has been removed from the -mm tree. Its filename was nilfs2-prevent-warning-in-nilfs_sufile_set_segment_usage.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Subject: nilfs2: prevent WARNING in nilfs_sufile_set_segment_usage() Date: Tue, 5 Dec 2023 17:59:47 +0900 If nilfs2 reads a disk image with corrupted segment usage metadata, and its segment usage information is marked as an error for the segment at the write location, nilfs_sufile_set_segment_usage() can trigger WARN_ONs during log writing. Segments newly allocated for writing with nilfs_sufile_alloc() will not have this error flag set, but this unexpected situation will occur if the segment indexed by either nilfs->ns_segnum or nilfs->ns_nextnum (active segment) was marked in error. Fix this issue by inserting a sanity check to treat it as a file system corruption. Since error returns are not allowed during the execution phase where nilfs_sufile_set_segment_usage() is used, this inserts the sanity check into nilfs_sufile_mark_dirty() which pre-reads the buffer containing the segment usage record to be updated and sets it up in a dirty state for writing. In addition, nilfs_sufile_set_segment_usage() is also called when canceling log writing and undoing segment usage update, so in order to avoid issuing the same kernel warning in that case, in case of cancellation, avoid checking the error flag in nilfs_sufile_set_segment_usage(). Link: https://lkml.kernel.org/r/20231205085947.4431-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+14e9f834f6ddecece094(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=14e9f834f6ddecece094 Tested-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/nilfs2/sufile.c | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-) --- a/fs/nilfs2/sufile.c~nilfs2-prevent-warning-in-nilfs_sufile_set_segment_usage +++ a/fs/nilfs2/sufile.c @@ -501,15 +501,38 @@ int nilfs_sufile_mark_dirty(struct inode down_write(&NILFS_MDT(sufile)->mi_sem); ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh); - if (!ret) { - mark_buffer_dirty(bh); - nilfs_mdt_mark_dirty(sufile); - kaddr = kmap_atomic(bh->b_page); - su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr); + if (ret) + goto out_sem; + + kaddr = kmap_atomic(bh->b_page); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr); + if (unlikely(nilfs_segment_usage_error(su))) { + struct the_nilfs *nilfs = sufile->i_sb->s_fs_info; + + kunmap_atomic(kaddr); + brelse(bh); + if (nilfs_segment_is_active(nilfs, segnum)) { + nilfs_error(sufile->i_sb, + "active segment %llu is erroneous", + (unsigned long long)segnum); + } else { + /* + * Segments marked erroneous are never allocated by + * nilfs_sufile_alloc(); only active segments, ie, + * the segments indexed by ns_segnum or ns_nextnum, + * can be erroneous here. + */ + WARN_ON_ONCE(1); + } + ret = -EIO; + } else { nilfs_segment_usage_set_dirty(su); kunmap_atomic(kaddr); + mark_buffer_dirty(bh); + nilfs_mdt_mark_dirty(sufile); brelse(bh); } +out_sem: up_write(&NILFS_MDT(sufile)->mi_sem); return ret; } @@ -536,9 +559,14 @@ int nilfs_sufile_set_segment_usage(struc kaddr = kmap_atomic(bh->b_page); su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr); - WARN_ON(nilfs_segment_usage_error(su)); - if (modtime) + if (modtime) { + /* + * Check segusage error and set su_lastmod only when updating + * this entry with a valid timestamp, not for cancellation. + */ + WARN_ON_ONCE(nilfs_segment_usage_error(su)); su->su_lastmod = cpu_to_le64(modtime); + } su->su_nblocks = cpu_to_le32(nblocks); kunmap_atomic(kaddr); _ Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are nilfs2-move-page-release-outside-of-nilfs_delete_entry-and-nilfs_set_link.patch nilfs2-eliminate-staggered-calls-to-kunmap-in-nilfs_rename.patch

10 months, 2 weeks

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[merged mm-hotfixes-stable] highmem-fix-a-memory-copy-problem-in-memcpy_from_folio.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: highmem: fix a memory copy problem in memcpy_from_folio has been removed from the -mm tree. Its filename was highmem-fix-a-memory-copy-problem-in-memcpy_from_folio.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Su Hui <suhui(a)nfschina.com> Subject: highmem: fix a memory copy problem in memcpy_from_folio Date: Thu, 30 Nov 2023 11:40:18 +0800 Clang static checker complains that value stored to 'from' is never read. And memcpy_from_folio() only copy the last chunk memory from folio to destination. Use 'to += chunk' to replace 'from += chunk' to fix this typo problem. Link: https://lkml.kernel.org/r/20231130034017.1210429-1-suhui@nfschina.com Fixes: b23d03ef7af5 ("highmem: add memcpy_to_folio() and memcpy_from_folio()") Signed-off-by: Su Hui <suhui(a)nfschina.com> Reviewed-by: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Ira Weiny <ira.weiny(a)intel.com> Cc: Jiaqi Yan <jiaqiyan(a)google.com> Cc: Nathan Chancellor <nathan(a)kernel.org> Cc: Nick Desaulniers <ndesaulniers(a)google.com> Cc: Peter Collingbourne <pcc(a)google.com> Cc: Tom Rix <trix(a)redhat.com> Cc: Tony Luck <tony.luck(a)intel.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/highmem.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/highmem.h~highmem-fix-a-memory-copy-problem-in-memcpy_from_folio +++ a/include/linux/highmem.h @@ -454,7 +454,7 @@ static inline void memcpy_from_folio(cha memcpy(to, from, chunk); kunmap_local(from); - from += chunk; + to += chunk; offset += chunk; len -= chunk; } while (len > 0); _ Patches currently in -mm which might be from suhui(a)nfschina.com are

10 months, 2 weeks

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[merged mm-hotfixes-stable] nilfs2-fix-missing-error-check-for-sb_set_blocksize-call.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: nilfs2: fix missing error check for sb_set_blocksize call has been removed from the -mm tree. Its filename was nilfs2-fix-missing-error-check-for-sb_set_blocksize-call.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Subject: nilfs2: fix missing error check for sb_set_blocksize call Date: Wed, 29 Nov 2023 23:15:47 +0900 When mounting a filesystem image with a block size larger than the page size, nilfs2 repeatedly outputs long error messages with stack traces to the kernel log, such as the following: getblk(): invalid block size 8192 requested logical block size: 512 ... Call Trace: dump_stack_lvl+0x92/0xd4 dump_stack+0xd/0x10 bdev_getblk+0x33a/0x354 __breadahead+0x11/0x80 nilfs_search_super_root+0xe2/0x704 [nilfs2] load_nilfs+0x72/0x504 [nilfs2] nilfs_mount+0x30f/0x518 [nilfs2] legacy_get_tree+0x1b/0x40 vfs_get_tree+0x18/0xc4 path_mount+0x786/0xa88 __ia32_sys_mount+0x147/0x1a8 __do_fast_syscall_32+0x56/0xc8 do_fast_syscall_32+0x29/0x58 do_SYSENTER_32+0x15/0x18 entry_SYSENTER_32+0x98/0xf1 ... This overloads the system logger. And to make matters worse, it sometimes crashes the kernel with a memory access violation. This is because the return value of the sb_set_blocksize() call, which should be checked for errors, is not checked. The latter issue is due to out-of-buffer memory being accessed based on a large block size that caused sb_set_blocksize() to fail for buffers read with the initial minimum block size that remained unupdated in the super_block structure. Since nilfs2 mkfs tool does not accept block sizes larger than the system page size, this has been overlooked. However, it is possible to create this situation by intentionally modifying the tool or by passing a filesystem image created on a system with a large page size to a system with a smaller page size and mounting it. Fix this issue by inserting the expected error handling for the call to sb_set_blocksize(). Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/nilfs2/the_nilfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/nilfs2/the_nilfs.c~nilfs2-fix-missing-error-check-for-sb_set_blocksize-call +++ a/fs/nilfs2/the_nilfs.c @@ -716,7 +716,11 @@ int init_nilfs(struct the_nilfs *nilfs, goto failed_sbh; } nilfs_release_super_block(nilfs); - sb_set_blocksize(sb, blocksize); + if (!sb_set_blocksize(sb, blocksize)) { + nilfs_err(sb, "bad blocksize %d", blocksize); + err = -EINVAL; + goto out; + } err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); if (err) _ Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are nilfs2-move-page-release-outside-of-nilfs_delete_entry-and-nilfs_set_link.patch nilfs2-eliminate-staggered-calls-to-kunmap-in-nilfs_rename.patch

10 months, 2 weeks

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