On Tue, Nov 7, 2017 at 2:28 AM, Fengguang Wu <fengguang.wu@xxxxxxxxx> wrote: > FYI This bug trace also contains inotify_read(). > > [ 3.365745] BUG: unable to handle kernel paging request at ffff8800172f8000 > [ 3.366661] IP: slob_free+0x1c4/0x276 > [ 3.373500] RBP: ffff8800172f7ffe Same gcc bug: it's a 2-byte read from the end of the page that has been turned by gcc into a 4-byte read, and causes an oops because your gcc version is bad. I *think* it's triggered by CONFIG_OPTIMIZE_FOR_SIZE=y, which causes gcc to generate garbage code. Yes, the 32-bit read is one byte shorter because it doesn't have a operand size prefix, but it's buggy. Linus