From 7f66fa14fe4f2ea56fda56e69f01c1cd474336d4 Mon Sep 17 00:00:00 2001 From: Petr Pavlu Date: May 23 2023 11:59:56 +0000 Subject: ring-buffer: Sync IRQ works before buffer destruction (git-fixes). --- diff --git a/patches.suse/ring-buffer-Sync-IRQ-works-before-buffer-destruction.patch b/patches.suse/ring-buffer-Sync-IRQ-works-before-buffer-destruction.patch new file mode 100644 index 0000000..94b11dd --- /dev/null +++ b/patches.suse/ring-buffer-Sync-IRQ-works-before-buffer-destruction.patch @@ -0,0 +1,95 @@ +From: Johannes Berg +Date: Thu, 27 Apr 2023 17:59:20 +0200 +Subject: ring-buffer: Sync IRQ works before buffer destruction +Git-commit: 675751bb20634f981498c7d66161584080cc061e +Patch-mainline: v6.4-rc1 +References: git-fixes + +If something was written to the buffer just before destruction, +it may be possible (maybe not in a real system, but it did +happen in ARCH=um with time-travel) to destroy the ringbuffer +before the IRQ work ran, leading this KASAN report (or a crash +without KASAN): + + BUG: KASAN: slab-use-after-free in irq_work_run_list+0x11a/0x13a + Read of size 8 at addr 000000006d640a48 by task swapper/0 + + CPU: 0 PID: 0 Comm: swapper Tainted: G W O 6.3.0-rc1 #7 + Stack: + 60c4f20f 0c203d48 41b58ab3 60f224fc + 600477fa 60f35687 60c4f20f 601273dd + 00000008 6101eb00 6101eab0 615be548 + Call Trace: + [<60047a58>] show_stack+0x25e/0x282 + [<60c609e0>] dump_stack_lvl+0x96/0xfd + [<60c50d4c>] print_report+0x1a7/0x5a8 + [<603078d3>] kasan_report+0xc1/0xe9 + [<60308950>] __asan_report_load8_noabort+0x1b/0x1d + [<60232844>] irq_work_run_list+0x11a/0x13a + [<602328b4>] irq_work_tick+0x24/0x34 + [<6017f9dc>] update_process_times+0x162/0x196 + [<6019f335>] tick_sched_handle+0x1a4/0x1c3 + [<6019fd9e>] tick_sched_timer+0x79/0x10c + [<601812b9>] __hrtimer_run_queues.constprop.0+0x425/0x695 + [<60182913>] hrtimer_interrupt+0x16c/0x2c4 + [<600486a3>] um_timer+0x164/0x183 + [...] + + Allocated by task 411: + save_stack_trace+0x99/0xb5 + stack_trace_save+0x81/0x9b + kasan_save_stack+0x2d/0x54 + kasan_set_track+0x34/0x3e + kasan_save_alloc_info+0x25/0x28 + ____kasan_kmalloc+0x8b/0x97 + __kasan_kmalloc+0x10/0x12 + __kmalloc+0xb2/0xe8 + load_elf_phdrs+0xee/0x182 + [...] + + The buggy address belongs to the object at 000000006d640800 + which belongs to the cache kmalloc-1k of size 1024 + The buggy address is located 584 bytes inside of + freed 1024-byte region [000000006d640800, 000000006d640c00) + +Add the appropriate irq_work_sync() so the work finishes before +the buffers are destroyed. + +Prior to the commit in the Fixes tag below, there was only a +single global IRQ work, so this issue didn't exist. + +Link: https://lore.kernel.org/linux-trace-kernel/20230427175920.a76159263122.I8295e405c44362a86c995e9c2c37e3e03810aa56@changeid + +Cc: stable@vger.kernel.org +Cc: Masami Hiramatsu +Fixes: 15693458c4bc ("tracing/ring-buffer: Move poll wake ups into ring buffer code") +Signed-off-by: Johannes Berg +Signed-off-by: Steven Rostedt (Google) +Acked-by: Petr Pavlu +--- + kernel/trace/ring_buffer.c | 4 ++++ + 1 file changed, 4 insertions(+) + +diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c +index 9a0cb94c3972..0d748f1f79ff 100644 +--- a/kernel/trace/ring_buffer.c ++++ b/kernel/trace/ring_buffer.c +@@ -1767,6 +1767,8 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) + struct list_head *head = cpu_buffer->pages; + struct buffer_page *bpage, *tmp; + ++ irq_work_sync(&cpu_buffer->irq_work.work); ++ + free_buffer_page(cpu_buffer->reader_page); + + if (head) { +@@ -1873,6 +1875,8 @@ ring_buffer_free(struct trace_buffer *buffer) + + cpuhp_state_remove_instance(CPUHP_TRACE_RB_PREPARE, &buffer->node); + ++ irq_work_sync(&buffer->irq_work.work); ++ + for_each_buffer_cpu(buffer, cpu) + rb_free_cpu_buffer(buffer->buffers[cpu]); + + diff --git a/series.conf b/series.conf index 14612d7..b77663e 100644 --- a/series.conf +++ b/series.conf @@ -63366,6 +63366,7 @@ patches.suse/USB-dwc3-fix-runtime-pm-imbalance-on-unbind.patch patches.suse/usb-chipidea-fix-missing-goto-in-ci_hdrc_probe.patch patches.suse/ring-buffer-Ensure-proper-resetting-of-atomic-variables-in-ring_buffer_reset_online_cpus.patch + patches.suse/ring-buffer-Sync-IRQ-works-before-buffer-destruction.patch patches.suse/powerpc-rtas-use-memmove-for-potentially-overlapping.patch patches.suse/workqueue-Fix-hung-time-report-of-worker-pools.patch patches.suse/workqueue-Warn-when-a-new-worker-could-not-be-create.patch