Hello,
syzbot found the following crash on:
HEAD commit: 3ffe1e79 Linux 4.14.138
git tree: linux-4.14.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=10b38402600000
kernel config:
https://syzkaller.appspot.com/x/.config?x=978e269523a888e8
dashboard link:
https://syzkaller.appspot.com/bug?extid=d8532c325bf5c40a1b85
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=13fd626a600000
C reproducer:
https://syzkaller.appspot.com/x/repro.c?x=1478459a600000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+d8532c...@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read)
audit: type=1400 audit(1565386695.424:36): avc: denied { map } for
pid=7035 comm="syz-executor139" path="/root/syz-executor139391520"
dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in bpf_skb_proto_xlat net/core/filter.c:2151
[inline]
BUG: KASAN: slab-out-of-bounds in ____bpf_skb_change_proto
net/core/filter.c:2189 [inline]
BUG: KASAN: slab-out-of-bounds in bpf_skb_change_proto+0xdbc/0x10f0
net/core/filter.c:2164
Read of size 2 at addr ffff888091537d40 by task syz-executor139/7035
CPU: 0 PID: 7035 Comm: syz-executor139 Not tainted 4.14.138 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
__asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
bpf_skb_proto_xlat net/core/filter.c:2151 [inline]
____bpf_skb_change_proto net/core/filter.c:2189 [inline]
bpf_skb_change_proto+0xdbc/0x10f0 net/core/filter.c:2164
bpf_prog_0a61b7f223ef83f3+0xdfd/0x1000
Allocated by task 0:
(stack is not available)
Freed by task 0:
(stack is not available)
The buggy address belongs to the object at ffff888091537d40
which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 0 bytes inside of
232-byte region [ffff888091537d40, ffff888091537e28)
The buggy address belongs to the page:
page:ffffea0002454dc0 count:1 mapcount:0 mapping:ffff8880915370c0 index:0x0
flags: 0x1fffc0000000100(slab)
raw: 01fffc0000000100 ffff8880915370c0 0000000000000000 000000010000000c
raw: ffffea0002361f60 ffff8880a9dcc248 ffff88821b719240 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888091537c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888091537c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff888091537d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888091537d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888091537e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
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