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authorSteven Rostedt (Google) <rostedt@goodmis.org>2023-03-01 20:00:53 -0500
committerSteven Rostedt (Google) <rostedt@goodmis.org>2023-03-09 22:17:06 -0500
commit9f116f76fa8c04c81aef33ad870dbf9a158e5b70 (patch)
treeb9d61d71b13ad325dac4932b3eb901e13618a998 /kernel/trace
parente0213434fe3e4a0d118923dc98d31e7ff1cd9e45 (diff)
tracing: Check field value in hist_field_name()
The function hist_field_name() cannot handle being passed a NULL field parameter. It should never be NULL, but due to a previous bug, NULL was passed to the function and the kernel crashed due to a NULL dereference. Mark Rutland reported this to me on IRC. The bug was fixed, but to prevent future bugs from crashing the kernel, check the field and add a WARN_ON() if it is NULL. Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by: Mark Rutland <mark.rutland@arm.com> Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers") Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_events_hist.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6e8ab726a7b5..486cca3c2b75 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1331,6 +1331,9 @@ static const char *hist_field_name(struct hist_field *field,
{
const char *field_name = "";
+ if (WARN_ON_ONCE(!field))
+ return field_name;
+
if (level > 1)
return field_name;