This is a note to let you know that I've just added the patch titled
tracing: Have the user copy of synthetic event address use correct context
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-have-the-user-copy-of-synthetic-event-address-use-correct-context.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4f7969bcd6d33042d62e249b41b5578161e4c868 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Date: Tue, 31 Oct 2023 15:10:33 -0400
Subject: tracing: Have the user copy of synthetic event address use correct context
From: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
commit 4f7969bcd6d33042d62e249b41b5578161e4c868 upstream.
A synthetic event is created by the synthetic event interface that can
read both user or kernel address memory. In reality, it reads any
arbitrary memory location from within the kernel. If the address space is
in USER (where CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE is set) then
it uses strncpy_from_user_nofault() to copy strings otherwise it uses
strncpy_from_kernel_nofault().
But since both functions use the same variable there's no annotation to
what that variable is (ie. __user). This makes sparse complain.
Quiet sparse by typecasting the strncpy_from_user_nofault() variable to
a __user pointer.
Link: https://lore.kernel.org/linux-trace-kernel/20231031151033.73c42e23@xxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events");
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@xxxxxxxxx/
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace_events_synth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -452,7 +452,7 @@ static unsigned int trace_string(struct
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)str_val < TASK_SIZE)
- ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
+ ret = strncpy_from_user_nofault(str_field, (const void __user *)str_val, STR_VAR_LEN_MAX);
else
#endif
ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-6.6/tracing-have-the-user-copy-of-synthetic-event-address-use-correct-context.patch
