general protection fault in scatterwalk_copychunks

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 9f31eb60 Linux 4.19.53
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16edf3bea00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7a36b9832db62b25
dashboard link: https://syzkaller.appspot.com/bug?extid=6db79dbcb84d882b32d0
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1480e26ea00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=108a3b2aa00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6db79d...@syzkaller.appspotmail.com

RBP: 0000000000000005 R08: 0000000100000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401f60
R13: 0000000000401ff0 R14: 0000000000000000 R15: 0000000000000000
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: 0 PID: 7936 Comm: syz-executor232 Not tainted 4.19.53+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:73 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:98 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:82 [inline]
RIP: 0010:scatterwalk_copychunks+0x4f0/0x6a0 crypto/scatterwalk.c:55
Code: 00 fc ff df 80 3c 02 00 0f 85 3d 01 00 00 49 8d 45 08 4d 89 2f 48 89
c2 48 89 45 b8 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 84
c0 74 08 3c 03 0f 8e 03 01 00 00 48 b8 00 00 00 00
RSP: 0018:ffff888096a0f098 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000021 RCX: ffffffff832122a9
RDX: 0000000000000001 RSI: ffffffff832122fb RDI: 0000000000000007
RBP: ffff888096a0f110 R08: ffff88809c31e600 R09: ffffed1011aa9005
R10: ffffed1011aa9004 R11: ffff88808d548020 R12: 0000000000000021
R13: 0000000000000000 R14: 0000000000000004 R15: ffff888096a0f158
FS: 0000000001aea880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000809fa000 CR4: 00000000001406f0
Call Trace:
scatterwalk_map_and_copy crypto/scatterwalk.c:72 [inline]
scatterwalk_map_and_copy+0x14d/0x1d0 crypto/scatterwalk.c:60
gcmaes_crypt_by_sg.constprop.0+0x408/0x1850
arch/x86/crypto/aesni-intel_glue.c:911
gcmaes_encrypt.constprop.0+0x62a/0xd90
arch/x86/crypto/aesni-intel_glue.c:932
generic_gcmaes_encrypt+0x108/0x159 arch/x86/crypto/aesni-intel_glue.c:1297
crypto_aead_encrypt include/crypto/aead.h:335 [inline]
gcmaes_wrapper_encrypt+0x15f/0x200 arch/x86/crypto/aesni-intel_glue.c:1130
crypto_aead_encrypt include/crypto/aead.h:335 [inline]
tls_do_encryption net/tls/tls_sw.c:193 [inline]
tls_push_record+0x9c0/0x13a0 net/tls/tls_sw.c:228
tls_sw_sendpage+0x540/0xd40 net/tls/tls_sw.c:583
inet_sendpage+0x168/0x630 net/ipv4/af_inet.c:815
kernel_sendpage+0x92/0xf0 net/socket.c:3377
sock_sendpage+0x8b/0xc0 net/socket.c:847
pipe_to_sendpage+0x296/0x360 fs/splice.c:452
splice_from_pipe_feed fs/splice.c:503 [inline]
__splice_from_pipe+0x391/0x7d0 fs/splice.c:627
splice_from_pipe+0x108/0x170 fs/splice.c:662
generic_splice_sendpage+0x3c/0x50 fs/splice.c:833
do_splice_from fs/splice.c:852 [inline]
do_splice+0x642/0x12c0 fs/splice.c:1148
__do_sys_splice fs/splice.c:1415 [inline]
__se_sys_splice fs/splice.c:1395 [inline]
__x64_sys_splice+0x2c6/0x330 fs/splice.c:1395
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440679
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:00007ffdfa5f3fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00007ffdfa5f4000 RCX: 0000000000440679
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000005 R08: 0000000100000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401f60
R13: 0000000000401ff0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace b31ac903d398e578 ]---
RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:73 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:98 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:82 [inline]
RIP: 0010:scatterwalk_copychunks+0x4f0/0x6a0 crypto/scatterwalk.c:55
Code: 00 fc ff df 80 3c 02 00 0f 85 3d 01 00 00 49 8d 45 08 4d 89 2f 48 89
c2 48 89 45 b8 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 84
c0 74 08 3c 03 0f 8e 03 01 00 00 48 b8 00 00 00 00
RSP: 0018:ffff888096a0f098 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000021 RCX: ffffffff832122a9
RDX: 0000000000000001 RSI: ffffffff832122fb RDI: 0000000000000007
RBP: ffff888096a0f110 R08: ffff88809c31e600 R09: ffffed1011aa9005
R10: ffffed1011aa9004 R11: ffff88808d548020 R12: 0000000000000021
R13: 0000000000000000 R14: 0000000000000004 R15: ffff888096a0f158
FS: 0000000001aea880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000809fa000 CR4: 00000000001406f0


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