syzbot


WARNING in fpu__copy

Status: fixed on 2018/01/31 00:24
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+368be9c49d7964232801d2a4576c6cf50cf934ab@syzkaller.appspotmail.com
Fix commit: 5663d8f9bbe4 kvm: x86: fix WARN due to uninitialized guest FPU state
First crash: 2378d, last: 2374d

Sample crash report:
WARNING: CPU: 1 PID: 3388 at ./arch/x86/include/asm/fpu/internal.h:340 copy_xregs_to_kernel arch/x86/include/asm/fpu/internal.h:340 [inline]
WARNING: CPU: 1 PID: 3388 at ./arch/x86/include/asm/fpu/internal.h:340 copy_fpregs_to_fpstate arch/x86/include/asm/fpu/internal.h:413 [inline]
WARNING: CPU: 1 PID: 3388 at ./arch/x86/include/asm/fpu/internal.h:340 fpu__copy+0x6b6/0x740 arch/x86/kernel/fpu/core.c:212
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3388 Comm: syz-executor0 Not tainted 4.15.0-rc4+ #229
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177
 fixup_bug arch/x86/kernel/traps.c:246 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1061
RIP: 0010:copy_xregs_to_kernel arch/x86/include/asm/fpu/internal.h:340 [inline]
RIP: 0010:copy_fpregs_to_fpstate arch/x86/include/asm/fpu/internal.h:413 [inline]
RIP: 0010:fpu__copy+0x6b6/0x740 arch/x86/kernel/fpu/core.c:212
RSP: 0018:ffff8801c5b3f298 EFLAGS: 00010293
RAX: ffff8801c1252680 RBX: 1ffff10038b67e55 RCX: ffffffff8127ec26
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801d32676c0
RBP: ffff8801c5b3f3f0 R08: 0000000000000000 R09: ffff8801d32676c0
R10: 0000000000000068 R11: ffffed003a64cf3f R12: ffff8801d3267680
R13: ffff8801c1253a80 R14: ffff8801c5b3f3c8 R15: ffff8801d32676c0
 arch_dup_task_struct+0x60/0x70 arch/x86/kernel/process.c:101
 dup_task_struct kernel/fork.c:531 [inline]
 copy_process.part.38+0x47a/0x4ac0 kernel/fork.c:1591
 copy_process kernel/fork.c:1566 [inline]
 _do_fork+0x1ef/0xfb0 kernel/fork.c:2045
 SYSC_clone kernel/fork.c:2155 [inline]
 SyS_clone+0x37/0x50 kernel/fork.c:2149
 do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x45113a
RSP: 002b:0000000000a2f9e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000a2f9e0 RCX: 000000000045113a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000a2fa20 R08: 0000000000000001 R09: 0000000000edf940
R10: 0000000000edfc10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000010
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2017/12/20 12:49 upstream 10a7e9d84915 2d836b1d .config console log report ci-upstream-kasan-gce
2017/12/16 11:57 upstream f6f3732162b5 b6f0c91b .config console log report ci-upstream-kasan-gce
2017/12/18 13:08 linux-next 6084b576dca2 d5beb42a .config console log report ci-upstream-next-kasan-gce
2017/12/18 04:21 linux-next 6084b576dca2 d5beb42a .config console log report ci-upstream-next-kasan-gce
2017/12/18 02:20 linux-next 6084b576dca2 d5beb42a .config console log report ci-upstream-next-kasan-gce
2017/12/17 11:28 linux-next 6084b576dca2 d5beb42a .config console log report ci-upstream-next-kasan-gce
2017/12/16 22:44 linux-next 6084b576dca2 b6f0c91b .config console log report ci-upstream-next-kasan-gce
2017/12/16 06:05 linux-next 6084b576dca2 ac20b98c .config console log report ci-upstream-next-kasan-gce
* Struck through repros no longer work on HEAD.