From 0a592dc7b5f717d21de3f6c82c3cda0585e32b83 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 7 Jan 2022 12:21:37 +0100 Subject: [PATCH] 4.19-stable patches added patches: tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch --- queue-4.19/series | 2 + ...cpu_buffer-validity-in-get_trace_buf.patch | 59 +++++++++++++++++++ ...ce_percpu_buffer-as-a-percpu-pointer.patch | 50 ++++++++++++++++ 3 files changed, 111 insertions(+) create mode 100644 queue-4.19/tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch create mode 100644 queue-4.19/tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch diff --git a/queue-4.19/series b/queue-4.19/series index e69de29bb2d..f2c49ecb132 100644 --- a/queue-4.19/series +++ b/queue-4.19/series @@ -0,0 +1,2 @@ +tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch +tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch diff --git a/queue-4.19/tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch b/queue-4.19/tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch new file mode 100644 index 00000000000..71972c5bb63 --- /dev/null +++ b/queue-4.19/tracing-fix-check-for-trace_percpu_buffer-validity-in-get_trace_buf.patch @@ -0,0 +1,59 @@ +From 823e670f7ed616d0ce993075c8afe0217885f79d Mon Sep 17 00:00:00 2001 +From: "Naveen N. Rao" +Date: Thu, 23 Dec 2021 16:04:38 +0530 +Subject: tracing: Fix check for trace_percpu_buffer validity in get_trace_buf() + +From: Naveen N. Rao + +commit 823e670f7ed616d0ce993075c8afe0217885f79d upstream. + +With the new osnoise tracer, we are seeing the below splat: + Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0) + BUG: Unable to handle kernel data access on read at 0xc7d880000 + Faulting instruction address: 0xc0000000002ffa10 + Oops: Kernel access of bad area, sig: 11 [#1] + LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries + ... + NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0 + LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0 + Call Trace: + [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair+0x3c/0x60 (unreliable) + [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf+0x70/0x90 + [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback+0x250/0x290 + [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710 + [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130 + [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main+0x264/0x270 + [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare+0x150/0x180 + [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common+0xf4/0x278 + +osnoise tracer on ppc64le is triggering osnoise_taint() for negative +duration in get_int_safe_duration() called from +trace_sched_switch_callback()->thread_exit(). + +The problem though is that the check for a valid trace_percpu_buffer is +incorrect in get_trace_buf(). The check is being done after calculating +the pointer for the current cpu, rather than on the main percpu pointer. +Fix the check to be against trace_percpu_buffer. + +Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.1640255304.git.naveen.n.rao@linux.vnet.ibm.com + +Cc: stable@vger.kernel.org +Fixes: e2ace001176dc9 ("tracing: Choose static tp_printk buffer by explicit nesting count") +Signed-off-by: Naveen N. Rao +Signed-off-by: Steven Rostedt +Signed-off-by: Greg Kroah-Hartman +--- + kernel/trace/trace.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/kernel/trace/trace.c ++++ b/kernel/trace/trace.c +@@ -2822,7 +2822,7 @@ static char *get_trace_buf(void) + { + struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); + +- if (!buffer || buffer->nesting >= 4) ++ if (!trace_percpu_buffer || buffer->nesting >= 4) + return NULL; + + buffer->nesting++; diff --git a/queue-4.19/tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch b/queue-4.19/tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch new file mode 100644 index 00000000000..bdd757bb0fe --- /dev/null +++ b/queue-4.19/tracing-tag-trace_percpu_buffer-as-a-percpu-pointer.patch @@ -0,0 +1,50 @@ +From f28439db470cca8b6b082239314e9fd10bd39034 Mon Sep 17 00:00:00 2001 +From: "Naveen N. Rao" +Date: Thu, 23 Dec 2021 16:04:39 +0530 +Subject: tracing: Tag trace_percpu_buffer as a percpu pointer + +From: Naveen N. Rao + +commit f28439db470cca8b6b082239314e9fd10bd39034 upstream. + +Tag trace_percpu_buffer as a percpu pointer to resolve warnings +reported by sparse: + /linux/kernel/trace/trace.c:3218:46: warning: incorrect type in initializer (different address spaces) + /linux/kernel/trace/trace.c:3218:46: expected void const [noderef] __percpu *__vpp_verify + /linux/kernel/trace/trace.c:3218:46: got struct trace_buffer_struct * + /linux/kernel/trace/trace.c:3234:9: warning: incorrect type in initializer (different address spaces) + /linux/kernel/trace/trace.c:3234:9: expected void const [noderef] __percpu *__vpp_verify + /linux/kernel/trace/trace.c:3234:9: got int * + +Link: https://lkml.kernel.org/r/ebabd3f23101d89cb75671b68b6f819f5edc830b.1640255304.git.naveen.n.rao@linux.vnet.ibm.com + +Cc: stable@vger.kernel.org +Reported-by: kernel test robot +Fixes: 07d777fe8c398 ("tracing: Add percpu buffers for trace_printk()") +Signed-off-by: Naveen N. Rao +Signed-off-by: Steven Rostedt +Signed-off-by: Greg Kroah-Hartman +--- + kernel/trace/trace.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +--- a/kernel/trace/trace.c ++++ b/kernel/trace/trace.c +@@ -2812,7 +2812,7 @@ struct trace_buffer_struct { + char buffer[4][TRACE_BUF_SIZE]; + }; + +-static struct trace_buffer_struct *trace_percpu_buffer; ++static struct trace_buffer_struct __percpu *trace_percpu_buffer; + + /* + * Thise allows for lockless recording. If we're nested too deeply, then +@@ -2841,7 +2841,7 @@ static void put_trace_buf(void) + + static int alloc_percpu_trace_buffer(void) + { +- struct trace_buffer_struct *buffers; ++ struct trace_buffer_struct __percpu *buffers; + + buffers = alloc_percpu(struct trace_buffer_struct); + if (WARN(!buffers, "Could not allocate percpu trace_printk buffer")) -- 2.47.3