kernel panic: kProc-ful Page Fault in trhe Kernel at ADDR!oc-ful Page Fault in the Kernel at ADDR

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: bf9a9ba0d6af Add panic_hwtf() for kernel faults
git tree: https://github.com/akaros/akaros.git/master
console output: https://syzkaller.appspot.com/x/log.txt?x=17217a58400000
kernel config: https://syzkaller.appspot.com/x/.config?x=efef8cf2939304d3
dashboard link: https://syzkaller.appspot.com/bug?extid=92c125d950399d37e562
compiler:

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+92c125...@syzkaller.appspotmail.com

kernel panic at kern/arch/x86/trap.c:309, from core 3: kProc-ful Page Fault
in trhe Kernel at 0x000000000000001b!oc-ful Page Fault in the Kernel at
0x0000000000
0HW0001 TRAP frame at 0xfffffff00006dd30 on core 3
b!buf 213, STAT_FIX_LEN_9P 49 00000
rbx 0xffff800007d3bc60
rcx 0xfffffff00006dea0
rdx 0xfffffff0000 IBIT16SZ 2, GBIT16(buf) 0 Ts is bad!
TIT16(buf) 0
h rbp 0xfffffff00006de38
rsi 0x0000 rsi 0x0000000000000000
rdi 0xfffffff00006dea0
r8 0x0000000000000001
r9 0xffffffffc8790880
r10 0x0000000000000030
r11 0xffff800014eacaa0
r12 0xffff80000217de80
r13 0x00000000200000c0
r14 0x0000000000000073
r15 0x0000000000000167
trap 0x0000000e Page Fault
gsbs 0xffffffffc8668140
fsbs 0x0000000000000000
err 0x--------00000000
rip 0xffffffffc20583b4
cs 0x------------0008
flag 0x0000000000010246
rsp 0xfffffff00006ddf8
ss 0x------------0010
Backtrace of kernel context on Core 3:
#01 [<0xffffffffc20583b4>] in sys_readlink at src/syscall.c:2037
#02 [<0xffffffffc20593c9>] in syscall at src/syscall.c:2528
#03 [<0xffffffffc2059584>] in run_local_syscall at src/syscall.c:2563
#04 [<0xffffffffc2059ab9>] in prep_syscalls at src/syscall.c:2583
#05 [<0xffffffffc20ab29a>] in sysenter_callwrapper at arch/x86/trap.c:851


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[Barret Rhoden]

On 2018-07-18 at 11:00 syzbot

#syz invalid