general protection fault in skb_clone

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11d31703b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=d773ea50fff14413786d
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f75f75b00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b69341b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d773ea...@syzkaller.appspotmail.com

RBP: 00007fff1441d840 R08: 0000000000000000 R09: 0000000000000001
R10: 00007fff1441d597 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fff1441d860 R14: 00007fff1441d850 R15: 00007fff1441d82c
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: 8361 Comm: syz-executor547 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:skb_clone+0xe9/0x3d0 net/core/skbuff.c:1285
Code: e8 bc 85 f1 fa 84 db 0f 85 f4 00 00 00 e8 7f 84 f1 fa 4c 8d bd 8e 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <0f> b6 04 02 4c 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 7a 02 00 00
RSP: 0018:ffff8880af78f5b8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880aa080ed0 RCX: 0000000000000000
RDX: 0000000000000011 RSI: ffffffff867100f1 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88809cd2b8a0
R13: 0000000000480020 R14: ffff88809cd2b880 R15: 000000000000008e
FS: 0000555557393300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f534de522c4 CR3: 000000009f53f000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
frame_get_stripped_skb net/hsr/hsr_forward.c:127 [inline]
hsr_forward_do net/hsr/hsr_forward.c:285 [inline]
hsr_forward_skb+0xf54/0x1c30 net/hsr/hsr_forward.c:373
hsr_handle_frame+0x33b/0x640 net/hsr/hsr_slave.c:50
__netif_receive_skb_core+0x929/0x3270 net/core/dev.c:4876
__netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:4952
__netif_receive_skb+0x27/0x1c0 net/core/dev.c:5066
netif_receive_skb_internal+0xf0/0x3f0 net/core/dev.c:5156
tun_rx_batched.isra.0+0x472/0x740 drivers/net/tun.c:1543
tun_get_user+0x2ee5/0x5100 drivers/net/tun.c:1974
tun_chr_write_iter+0xdb/0x1d0 drivers/net/tun.c:2007
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f534ddb2f73
Code: e9 0e ec ff ff bf 01 00 00 00 e8 a8 6f 00 00 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18
RSP: 002b:00007fff1441d7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f534ddb2f73
RDX: 000000000000000e RSI: 0000000020000100 RDI: 00000000000000c8
RBP: 00007fff1441d840 R08: 0000000000000000 R09: 0000000000000001
R10: 00007fff1441d597 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fff1441d860 R14: 00007fff1441d850 R15: 00007fff1441d82c
Modules linked in:
---[ end trace 418dabf69e2b8c19 ]---
RIP: 0010:skb_clone+0xe9/0x3d0 net/core/skbuff.c:1285
Code: e8 bc 85 f1 fa 84 db 0f 85 f4 00 00 00 e8 7f 84 f1 fa 4c 8d bd 8e 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <0f> b6 04 02 4c 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 7a 02 00 00
RSP: 0018:ffff8880af78f5b8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880aa080ed0 RCX: 0000000000000000
RDX: 0000000000000011 RSI: ffffffff867100f1 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88809cd2b8a0
R13: 0000000000480020 R14: ffff88809cd2b880 R15: 000000000000008e
FS: 0000555557393300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f534de522c4 CR3: 000000009f53f000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: e8 bc 85 f1 fa callq 0xfaf185c1
5: 84 db test %bl,%bl
7: 0f 85 f4 00 00 00 jne 0x101
d: e8 7f 84 f1 fa callq 0xfaf18491
12: 4c 8d bd 8e 00 00 00 lea 0x8e(%rbp),%r15
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 4c 89 fa mov %r15,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 4c 89 fa mov %r15,%rdx
31: 83 e2 07 and $0x7,%edx
34: 38 d0 cmp %dl,%al
36: 7f 08 jg 0x40
38: 84 c0 test %al,%al
3a: 0f 85 7a 02 00 00 jne 0x2ba


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