general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 13720 Comm: syz-executor.5 Not tainted 5.9.0-rc5-next-20200914-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:shmem_getpage_gfp+0xac6/0x2400 mm/shmem.c:1995
Code: 00 00 e8 ad ce d5 ff 83 fb 04 0f 85 e3 06 00 00 e8 1f d2 d5 ff 49 8d 7e 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c5 17 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc90016b27948 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffea0001e02d00 RCX: ffffc900130a6000
RDX: 0000000000000004 RSI: ffffffff819cf951 RDI: 0000000000000020
RBP: ffffea0001e02dc0 R08: 0000000000000001 R09: ffffea0001e02df7
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: ffff888059e8cca0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f8180daa700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000340 CR3: 000000008e5d6000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_file_read_iter+0x57d/0xd30 mm/shmem.c:2606
 call_read_iter include/linux/fs.h:1889 [inline]
 do_iter_readv_writev+0x56a/0x740 fs/read_write.c:728
 do_iter_read+0x285/0x6e0 fs/read_write.c:970
 vfs_readv+0xe5/0x150 fs/read_write.c:1090
 do_preadv fs/read_write.c:1182 [inline]
 __do_sys_preadv fs/read_write.c:1232 [inline]
 __se_sys_preadv fs/read_write.c:1227 [inline]
 __x64_sys_preadv+0x231/0x310 fs/read_write.c:1227
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5f9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8180da9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000025900 RCX: 000000000045d5f9
RDX: 0000000000000001 RSI: 0000000020000880 RDI: 0000000000000003
RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffe09289c5f R14: 00007f8180daa9c0 R15: 000000000118cf4c
Modules linked in:
---[ end trace 34b86c12f34977ed ]---
RIP: 0010:shmem_getpage_gfp+0xac6/0x2400 mm/shmem.c:1995
Code: 00 00 e8 ad ce d5 ff 83 fb 04 0f 85 e3 06 00 00 e8 1f d2 d5 ff 49 8d 7e 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c5 17 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc90016b27948 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffea0001e02d00 RCX: ffffc900130a6000
RDX: 0000000000000004 RSI: ffffffff819cf951 RDI: 0000000000000020
RBP: ffffea0001e02dc0 R08: 0000000000000001 R09: ffffea0001e02df7
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: ffff888059e8cca0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f8180daa700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000280 CR3: 000000008e5d6000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400