Hi Willem, On Thu, 3 Jan 2019 13:41:43 -0600 Willem de Bruijn <willemdebruijn.ker...@gmail.com> wrote:
> On Thu, Jan 3, 2019 at 1:39 PM Willem de Bruijn > <willemdebruijn.ker...@gmail.com> wrote: > > > > On Thu, Jan 3, 2019 at 7:07 AM syzbot > > <syzbot+4ad25edc7a33e4ab9...@syzkaller.appspotmail.com> wrote: > > > > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 195303136f19 Merge tag 'kconfig-v4.21-2' of > > > git://git.kern.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=12245d8f400000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=5e7dc790609552d7 > > > dashboard link: > > > https://syzkaller.appspot.com/bug?extid=4ad25edc7a33e4ab91e0 > > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+4ad25edc7a33e4ab9...@syzkaller.appspotmail.com > > > > > > protocol 88fb is buggy, dev hsr_slave_1 > > > protocol 88fb is buggy, dev hsr_slave_0 > > > protocol 88fb is buggy, dev hsr_slave_1 > > > FAT-fs (loop0): invalid media value (0x00) > > > FAT-fs (loop0): Can't find a valid FAT filesystem > > > Kernel panic - not syncing: stack-protector: Kernel stack is corrupted > > > in: > > > > This sounds similar to the stack corruption fixed recently in commit > > e7cc082455cb ("udp: Support for error handlers of tunnels ..."). > > > > That fix is for ipv4 gue_err(). ipv6 gue6_err() probably needs the same. > > Correction. The fix is 11789039da ("fou: prevent unbounded recursion > in GUE error handler") Yes, I looked into this, the fix for that issue is on the tree tested by syzbot, and I think this is unrelated, also because KASan should say something before we hit that. By the way, do you happen to know if I objects from kernels tested by syzbot are stored anywhere? It would be helpful to know for sure what's at udp4_lib_lookup2+0x7ea. -- Stefano
