kernel panic: Proc-ful Page FPault in theroc-ful Page Fault in the Kernel at ADDR!nb Kernel uf at ADDR!63

[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=1055eee0400000
kernel config: https://syzkaller.appspot.com/x/.config?x=efef8cf2939304d3
dashboard link: https://syzkaller.appspot.com/bug?extid=df85cf7d413b582a4c69
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+df85cf...@syzkaller.appspotmail.com

bash-4.3$ kernel panic at kern/arch/x86/trap.c:309, from core 1: Proc-ful
Page FPault in theroc-ful Page Fault in the Kernel at 0x000000000000001b!nb
Kernel uf at 0x0000000000001001b!63
,HW TRAP frame at 0xfW TRAP frame at 0xfff) 0 f0000b5d30 on core 1
B rax 0 rax x0000000000000000
rbx 0xffff80000xfff0671f8002600006710260
T rcx 0xffffrcnbuf 4096, S 4096, STTAT_FIX_LEN_9P 49 AT16(buf) 0 PB
rdx rd0xx 0xfffffffffff0000fff0000bb5d6c5d6c
T rbp 0xffff rbp2nbuf 224, STAT_FIX_24, STAT_FIX_LEN_9P L00000
rsi 49 0x00000 016BI(buf) T10
6 rdi 0xfffffff0000b5ea0
r8 0x0000000000000001
0xfffff r9 0xffffffffc8790880
f 0000000030 This is bad!
is is bad!
nT_FIX_LEN_9P br11 0xffff8000067453a0
49 BTI1T16SZ 2, GB6SIT16(buf) 0 Z bad!
TIhis is bad!
T16(buf) 0
n r12 0xffff800002182ac0
r13 0x0000000020000040
49 r16SZ 2, GBIT16(buf) 0
B r14 r14 0x0000000000000073 This is bad!
s baSTAT_FIX_LnEbuf 224, STAT_FIX_LENN_9P _84
r15 0x0000000000000084
4 t
BIT16SZ 2, GBIT16(buf) 0 TThis is bad!
s is bad!
IT16(buf) 0 ult
gsbs 0xffffffffc8667c40
fsbs 0x0000000000000000
err 0x--------00000000
rip 0xffffffffc20583b4
cs 0x------------0008
flag 0x0000000000010246
rsp 0xfffffff0000b5df8
ss 0x------------0010
Backtrace of kernel context on Core 1:
#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 17:00 syzbot

#syz invalid