From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
stable@vger.kernel.org, kernel test robot <lkp@intel.com>
Subject: [for-next][PATCH 03/12] tracing: Have the user copy of synthetic event address use correct context
Date: Wed, 01 Nov 2023 17:37:21 -0400 [thread overview]
Message-ID: <20231101213802.233842141@goodmis.org> (raw)
In-Reply-To: <20231101213718.381015321@goodmis.org>
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
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@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events");
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace_events_synth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 14cb275a0bab..846e02c0fb59 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -452,7 +452,7 @@ static unsigned int trace_string(struct synth_trace_event *entry,
#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);
--
2.42.0
next prev parent reply other threads:[~2023-11-01 21:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-01 21:37 [for-next][PATCH 00/12] tracing: Final (hopefully!) updates for v6.7 Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 01/12] tracing: Have trace_event_file have ref counters Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 02/12] eventfs: Remove extra dget() in eventfs_create_events_dir() Steven Rostedt
2023-11-01 21:37 ` Steven Rostedt [this message]
2023-11-01 21:37 ` [for-next][PATCH 04/12] eventfs: Fix kerneldoc of eventfs_remove_rec() Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 05/12] eventfs: Remove "is_freed" union with rcu head Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 06/12] eventfs: Have a free_ei() that just frees the eventfs_inode Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 07/12] eventfs: Test for ei->is_freed when accessing ei->dentry Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 08/12] eventfs: Save ownership and mode Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 09/12] eventfs: Hold eventfs_mutex when calling callback functions Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 10/12] eventfs: Delete eventfs_inode when the last dentry is freed Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 11/12] eventfs: Remove special processing of dput() of events directory Steven Rostedt
2023-11-01 21:37 ` [for-next][PATCH 12/12] eventfs: Use simple_recursive_removal() to clean up dentries Steven Rostedt
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