On 12/29/2017 11:29 PM, intrigeri wrote: > Control: forwarded -1 appar...@lists.ubuntu.com > > Hi AppArmor kernel developers, > > we got this bug reported in Debian: > > Kertesz Laszlo: >> * What led up to the situation? >> Installed kernel 4.14 in Debian Testing and ever since at every upgrade >> where systemd or other important >> packages were upgraded the system froze with the last 2 lines in the >> system log: > >> Dec 29 21:25:26 laca-desktop kernel: BUG: unable to handle kernel NULL >> pointer dereference at 0000000000000005 >> Dec 29 21:25:26 laca-desktop kernel: IP: __task_pid_nr_ns+0xc7/0xf0 > >> The system became unresponsive, not even the sysrq combinations were >> working >> * What exactly did you do (or not do) that was effective (or >> ineffective)? >> Restarted ran dpkg --configure -a and every time the system froze >> Booting with the 4.13 kernel was fine, dpkg finished its run > >> At the next upgrade i still got the freeze, after reboot i disabled the >> kernel security features with the kernel command line security=false > >> * What was the outcome of this action? >> dpkg was working fine with the kernel 4.14 too > > Do you need more info from me or from the bug reporter (Kertesz > Laszlo, Cc'ed)? >
yes please. This really isn't enough info to debug off of. AppArmor does not call __task_pid_nr_ns() nor even any of the fns() that call it directly. We need more of a call trace to even have a chance of chasing this down.