KASAN: out-of-bounds Read in __netif_receive_skb_list_core

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ca497fb6 taprio: remove unused variable 'entry_list_policy'
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14e0bc6a600000
kernel config: https://syzkaller.appspot.com/x/.config?x=d4cf1ffb87d590d7
dashboard link: https://syzkaller.appspot.com/bug?extid=ef24df1cd86a643cd90d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [a...@kernel.org b...@vger.kernel.org dan...@iogearbox.net
da...@davemloft.net edum...@google.com ha...@kernel.org
jakub.k...@netronome.com jaso...@redhat.com john.fa...@gmail.com
ka...@fb.com linux-...@vger.kernel.org m...@redhat.com
net...@vger.kernel.org nicolas...@6wind.com s...@google.com
songliu...@fb.com wang...@baidu.com y...@fb.com net...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+ef24df...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: out-of-bounds in __netif_receive_skb_list_core+0x810/0x9d0
net/core/dev.c:5078
Read of size 8 at addr ffff8880655af238 by task syz-executor.3/16978

CPU: 1 PID: 16978 Comm: syz-executor.3 Not tainted 5.3.0-rc3+ #125
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
__kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
kasan_report+0x12/0x17 mm/kasan/common.c:612
__asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
__netif_receive_skb_list_core+0x810/0x9d0 net/core/dev.c:5078
__netif_receive_skb_list net/core/dev.c:5149 [inline]
netif_receive_skb_list_internal+0x7eb/0xe60 net/core/dev.c:5244
gro_normal_list.part.0+0x1e/0xb0 net/core/dev.c:5757
gro_normal_list net/core/dev.c:5755 [inline]
gro_normal_one net/core/dev.c:5769 [inline]
napi_frags_finish net/core/dev.c:5782 [inline]
napi_gro_frags+0xa6a/0xea0 net/core/dev.c:5855
tun_get_user+0x2e98/0x3fa0 drivers/net/tun.c:1974
tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2020
call_write_iter include/linux/fs.h:1870 [inline]
do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693
do_iter_write fs/read_write.c:970 [inline]
do_iter_write+0x184/0x610 fs/read_write.c:951
vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015
do_writev+0x15b/0x330 fs/read_write.c:1058
__do_sys_writev fs/read_write.c:1131 [inline]
__se_sys_writev fs/read_write.c:1128 [inline]
__x64_sys_writev+0x75/0xb0 fs/read_write.c:1128
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4596e1
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 b9 fb ff c3 48
83 ec 08 e8 fa 2c 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48
89 c2 e8 43 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f0f28afaba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000083 RCX: 00000000004596e1
RDX: 0000000000000001 RSI: 00007f0f28afac00 RDI: 00000000000000f0
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f0f28afb6d4
R13: 00000000004c8783 R14: 00000000004df580 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea0001956bc0 refcount:0 mapcount:0 mapping:0000000000000000
index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffffffa9910101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8880655af100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880655af180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8880655af200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff8880655af280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880655af300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.