general protection fault in transparent_hugepage_enabled

From: syzbot
Date: Mon Dec 24 2018 - 10:48:12 EST


Hello,

syzbot found the following crash on:

HEAD commit: 6a1d293238c1 Add linux-next specific files for 20181224
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=149a2add400000
kernel config: https://syzkaller.appspot.com/x/.config?x=c190b602a5d2d731
dashboard link: https://syzkaller.appspot.com/bug?extid=a5fea9200aefd1cf4818
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1798bfb7400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f4dc57400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a5fea9200aefd1cf4818@xxxxxxxxxxxxxxxxxxxxxxxxx

sshd (6016) used greatest stack depth: 15720 bytes left
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 6032 Comm: syz-executor045 Not tainted 4.20.0-rc7-next-20181224 #187
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:transparent_hugepage_enabled+0x8c/0x5e0 mm/huge_memory.c:69
Code: 80 3c 02 00 0f 85 ae 04 00 00 4c 8b a3 a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 b8 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 91 04 00 00 49 8b bc 24 b8 01 00 00 e8 2d 70 e6
RSP: 0018:ffff8881c2237138 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881c2bdbc60 RCX: 0000000000000000
RDX: 0000000000000037 RSI: ffffffff81c8fa1a RDI: 00000000000001b8
RBP: ffff8881c2237160 R08: ffffed10383b25ed R09: ffffed10383b25ec
R10: ffffed10383b25ec R11: ffff8881c1d92f63 R12: 0000000000000000
R13: ffff8881c2bdbd00 R14: dffffc0000000000 R15: 0000000000000f5e
FS: 0000000001a48880(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b58000 CR3: 00000001c2210000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
show_smap+0x167/0x580 fs/proc/task_mmu.c:805
traverse+0x344/0x7b0 fs/seq_file.c:113
seq_read+0xc76/0x1150 fs/seq_file.c:188
do_loop_readv_writev fs/read_write.c:700 [inline]
do_iter_read+0x4bc/0x670 fs/read_write.c:924
vfs_readv+0x175/0x1c0 fs/read_write.c:986
kernel_readv fs/splice.c:362 [inline]
default_file_splice_read+0x539/0xb20 fs/splice.c:417
do_splice_to+0x12e/0x190 fs/splice.c:880
splice_direct_to_actor+0x31c/0x9d0 fs/splice.c:957
do_splice_direct+0x2d4/0x420 fs/splice.c:1066
do_sendfile+0x62a/0xe50 fs/read_write.c:1439
__do_sys_sendfile64 fs/read_write.c:1494 [inline]
__se_sys_sendfile64 fs/read_write.c:1486 [inline]
__x64_sys_sendfile64+0x15d/0x250 fs/read_write.c:1486
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440089
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff3d710a18 EFLAGS: 00000213 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fff3d710a20 RCX: 0000000000440089
RDX: 0000000020b58000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000010 R09: 65732f636f72702f
R10: 000000000000ffff R11: 0000000000000213 R12: 0000000000401970
R13: 0000000000401a00 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace faf026efd8795e93 ]---
RIP: 0010:transparent_hugepage_enabled+0x8c/0x5e0 mm/huge_memory.c:69
Code: 80 3c 02 00 0f 85 ae 04 00 00 4c 8b a3 a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 b8 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 91 04 00 00 49 8b bc 24 b8 01 00 00 e8 2d 70 e6
RSP: 0018:ffff8881c2237138 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881c2bdbc60 RCX: 0000000000000000
RDX: 0000000000000037 RSI: ffffffff81c8fa1a RDI: 00000000000001b8
RBP: ffff8881c2237160 R08: ffffed10383b25ed R09: ffffed10383b25ec
R10: ffffed10383b25ec R11: ffff8881c1d92f63 R12: 0000000000000000
R13: ffff8881c2bdbd00 R14: dffffc0000000000 R15: 0000000000000f5e
FS: 0000000001a48880(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b58000 CR3: 00000001c2210000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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