On 22-09-19, 23:12, Dmitry Osipenko wrote: > This patch causes use-after-free on a cpufreq driver module reload. Please take a look, thanks in advance. > > > [ 87.952369] ================================================================== > [ 87.953259] BUG: KASAN: use-after-free in notifier_chain_register+0x4f/0x9c > [ 87.954031] Read of size 4 at addr e6abbd0c by task modprobe/243 Hi Dmitry, I tried to reproduce it on my ubuntu on ARM64 setup and I couldn't hit these issues on v5.4-rc1 with Kasan built in. I then enabled Kasan (tried both inline and outline instrumentation) but I couldn't get past the issues with module insertion. It fails like this for me: root@linaro-developer:~/work# insmod cpufreq-dt.ko [ 72.985974] cpufreq_dt: Unknown symbol __asan_report_load1_noabort (err -2) [ 72.993164] cpufreq_dt: Unknown symbol __asan_report_load4_noabort (err -2) [ 73.000307] cpufreq_dt: Unknown symbol __asan_report_load8_noabort (err -2) [ 73.007451] cpufreq_dt: Unknown symbol __asan_report_store1_noabort (err -2) [ 73.014643] cpufreq_dt: Unknown symbol __asan_register_globals (err -2) [ 73.021409] cpufreq_dt: Unknown symbol __asan_unregister_globals (err -2) [ 73.028349] cpufreq_dt: Unknown symbol __asan_report_store8_noabort (err -2) [ 73.035543] cpufreq_dt: Unknown symbol __asan_report_store4_noabort (err -2) insmod: ERROR: could not insert module cpufreq-dt.ko: Unknown symbol in module I tried to search for these errors but couldn't find why I am getting these and why the symbols are missing here. Can you suggest something here ? -- viresh
