Hi,
I have encountered a kernel BUG when running ltp ftrace-stress-test
on 4.19.48.
[ 209.704855] LTP: starting ftrace-stress-test (ftrace_stress_test.sh 90)
[ 209.739412] Scheduler tracepoints stat_sleep, stat_iowait, stat_blocked and
stat_runtime require the kernel parameter schedstats=enable or
kernel.sched_schedstats=1
[ 212.054506] kernel tried to execute NX-protected page - exploit attempt?
(uid: 0)
[ 212.055595] BUG: unable to handle kernel paging request at ffffffffc0349000
[ 212.056589] PGD d00c067 P4D d00c067 PUD d00e067 PMD 23673e067 PTE
800000023457f061
[ 212.057759] Oops: 0011 [#1] SMP PTI
[ 212.058303] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 4.19.48
#112
After some investigation I have found that it is introduced by commit
8715ce033eb3 ("x86/modules: Avoid breaking W^X while loading modules"),
and then revert this commit the issue is gone.
I have also tested the same case on 5.2-rc3 as well as right at
upstream commit f2c65fb3221a ("x86/modules: Avoid breaking W^X while
loading modules"), which has been merged in 5.2-rc1, it doesn't
happen.
So I don't know why only stable has this issue while upstream doesn't.
Thanks,
Joseph
