Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'trace-v5.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Fix the histogram logic from possibly crashing the kernel
Working on the histogram code, I found that if you dereference a char
pointer in a trace event that happens to point to user space, it can
crash the kernel, as it does no checks of that pointer. I have code
coming that will do this better, so just remove this ability to treat
character pointers in trace events as stings in the histogram"
* tag 'trace-v5.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not reference char * as a string in histograms
+3
-3
+3
-3
kernel/trace/trace_events_hist.c
+3
-3
kernel/trace/trace_events_hist.c
···
1689
1689
if (WARN_ON_ONCE(!field))
1690
1690
goto out;
1691
1691
1692
-
if (is_string_field(field)) {
1692
+
/* Pointers to strings are just pointers and dangerous to dereference */
1693
+
if (is_string_field(field) &&
1694
+
(field->filter_type != FILTER_PTR_STRING)) {
1693
1695
flags |= HIST_FIELD_FL_STRING;
1694
1696
1695
1697
hist_field->size = MAX_FILTER_STR_VAL;
···
4497
4495
field = key_field->field;
4498
4496
if (field->filter_type == FILTER_DYN_STRING)
4499
4497
size = *(u32 *)(rec + field->offset) >> 16;
4500
-
else if (field->filter_type == FILTER_PTR_STRING)
4501
-
size = strlen(key);
4502
4498
else if (field->filter_type == FILTER_STATIC_STRING)
4503
4499
size = field->size;
4504
4500