diff options
author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-11-13 01:02:08 +0900 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-26 10:39:13 +0100 |
commit | 5b2f2cbbc925ac5ce72547a163a69fa90a67e1d0 (patch) | |
tree | 430e7067552f6617d81529c7d3c7954846697d43 /kernel | |
parent | 1d61255327559b203a02d81dbb78ab1a0cd61709 (diff) |
tracing/histogram: Do not copy the fixed-size char array field over the field size
[ Upstream commit 63f84ae6b82bb4dff672f76f30c6fd7b9d3766bc ]
Do not copy the fixed-size char array field of the events over
the field size. The histogram treats char array as a string and
there are 2 types of char array in the event, fixed-size and
dynamic string. The dynamic string (__data_loc) field must be
null terminated, but the fixed-size char array field may not
be null terminated (not a string, but just a data).
In that case, histogram can copy the data after the field.
This uses the original field size for fixed-size char array
field to restrict the histogram not to access over the original
field size.
Link: https://lkml.kernel.org/r/163673292822.195747.3696966210526410250.stgit@devnote2
Fixes: 02205a6752f2 (tracing: Add support for 'field variables')
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/trace_events_hist.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 1b7f90e00eb0..642e4645f640 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1684,9 +1684,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, if (!hist_field->type) goto free; - if (field->filter_type == FILTER_STATIC_STRING) + if (field->filter_type == FILTER_STATIC_STRING) { hist_field->fn = hist_field_string; - else if (field->filter_type == FILTER_DYN_STRING) + hist_field->size = field->size; + } else if (field->filter_type == FILTER_DYN_STRING) hist_field->fn = hist_field_dynstring; else hist_field->fn = hist_field_pstring; @@ -2624,7 +2625,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt, char *str = elt_data->field_var_str[j++]; char *val_str = (char *)(uintptr_t)var_val; - strscpy(str, val_str, STR_VAR_LEN_MAX); + strscpy(str, val_str, val->size); var_val = (u64)(uintptr_t)str; } tracing_map_set_var(elt, var_idx, var_val); @@ -4472,7 +4473,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, str = elt_data->field_var_str[idx]; val_str = (char *)(uintptr_t)hist_val; - strscpy(str, val_str, STR_VAR_LEN_MAX); + strscpy(str, val_str, hist_field->size); hist_val = (u64)(uintptr_t)str; } |