From: Donggeun Yoo <donggeunyoo.kernel@gmail.com> mainline inclusion from mainline-v7.3-rc3 commit 7f711e62355bb3123a2ca2f97a2facbfebc678c6 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9956 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- "cpu", "CPU", "stacktrace" and "STACKTRACE" are generic fields, defined with an offset and a size of zero so that the filter code can match them by name. parse_field() maps them onto their common_* equivalents for backward compatibility, but unlike the common_* names it hands the placeholder back to the caller instead of NULL. create_hist_field() takes a non-NULL field as a promise that the record carries a stacktrace and picks HIST_FIELD_FN_STACK, so the __data_loc word is read from offset 0, that is from common_type, and its low 16 bits are followed as an offset into the record. What is found there becomes the length of an unbounded memcpy. Pick an event whose id is small enough that the offset stays inside its own record and the length is a kernel text address: # cd /sys/kernel/tracing # echo 'hist:keys=STACKTRACE' > events/ftrace/print/trigger # echo hello > trace_marker Oops: general protection fault, probably for non-canonical address RIP: 0010:rb_next+0x23/0x60 </IRQ> RIP: 0010:memcpy+0xc/0x30 event_hist_trigger+0x2e7/0x12c0 Kernel panic - not syncing: Fatal exception in interrupt Leave the field NULL, which is what the comment above the branch says the code does and what common_stacktrace already does. FILTER_CPU and FILTER_COMM are left alone, their create_hist_field() branches never look at the field. Cc: stable@vger.kernel.org Fixes: 4b512860bdbd ("tracing: Rename stacktrace field to common_stacktrace") Link: https://patch.msgid.link/20260907155045.692664-3-donggeunyoo.kernel@gmail.co... Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Conflicts: kernel/trace/trace_events_hist.c [Context conflict] Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- kernel/trace/trace_events_hist.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 40e81642c75d..d5602a4c6eb5 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2401,6 +2401,7 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, *flags |= HIST_FIELD_FL_CPU; } else if (field && field->filter_type == FILTER_STACKTRACE) { *flags |= HIST_FIELD_FL_STACKTRACE; + field = NULL; } else { hist_err(tr, HIST_ERR_FIELD_NOT_FOUND, errpos(field_name)); -- 2.34.1