On Thu, 8 Nov 2018 08:41:47 -0600 Tom Zanussi <[email protected]> wrote:
> From: Tom Zanussi <[email protected]> > > Hi Steve, > > This is a fix for a user-reported bug in the hist triggers, where if a > variable reference is used in an expression in a histogram key, it > results in a NULL pointer dereference and subsequent Oops. How does one add a variable reference as an expression in a histogram key? Can you show an example? -- Steve > > I separated the fix into two small patches, the first preventing the > immediate problem bu disallowing a var_ref from ever accessing a NULL > element, and the second disallowing a user from ever constructing such > a key. > > Thanks, > > Tom > > The following changes since commit ee474b81fe5aa5dc0faae920bf66240fbf55f891: > > tracing/kprobes: Fix strpbrk() argument order (2018-11-05 09:47:14 -0500) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux-trace.git > ftrace/key-ref-fix > > Tom Zanussi (2): > tracing: Prevent hist_field_var_ref() from accessing NULL > tracing_map_elts > tracing: Check keys for variable references in expressions too > > kernel/trace/trace_events_hist.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) >
