On Thu, 17 Apr 2025 16:29:27 -0700 Andrew Morton <[email protected]> wrote:
> On Thu, 17 Apr 2025 18:30:03 -0400 Steven Rostedt <[email protected]> wrote: > > > From: Steven Rostedt <[email protected]> > > > > The filter string testing uses strncpy_from_kernel/user_nofault() to > > retrieve the string to test the filter against. The if() statement was > > incorrect as it considered 0 as a fault, when it is only negative that it > > faulted. > > changelog forgot to describe the userspace-visible effects of the bug? > > > Cc: [email protected] > > Which is more important when proposing this! > I can update the change log to show how it's broken. In fact, I'm working on a selftest to catch it if it breaks again. # cd /sys/kernel/tracing # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter # ls /proc/$$/maps # cat trace If it works you get: ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0) If not, you get nothing! -- Steve
