Messages in this thread | | | Date | Wed, 13 Jun 2018 15:17:02 -0700 | Subject | KASAN: slab-out-of-bounds Read in bpf_skb_change_head | From | syzbot <> |
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Hello,
syzbot found the following crash on:
HEAD commit: 75d4e704fa8d netdev-FAQ: clarify DaveM's position for stab.. git tree: bpf-next console output: https://syzkaller.appspot.com/x/log.txt?x=16bd21af800000 kernel config: https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44 dashboard link: https://syzkaller.appspot.com/bug?extid=567faa843005dda30737 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1039185f800000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11e85cff800000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+567faa843005dda30737@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KASAN: slab-out-of-bounds in ____bpf_skb_change_head net/core/filter.c:2921 [inline] BUG: KASAN: slab-out-of-bounds in bpf_skb_change_head+0x80c/0x9d0 net/core/filter.c:2917 Read of size 4 at addr ffff8801d94ea680 by task syz-executor991/4551
CPU: 0 PID: 4551 Comm: syz-executor991 Not tainted 4.17.0-rc7+ #38 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 ____bpf_skb_change_head net/core/filter.c:2921 [inline] bpf_skb_change_head+0x80c/0x9d0 net/core/filter.c:2917
Allocated by task 0: (stack is not available)
Freed by task 0: (stack is not available)
The buggy address belongs to the object at ffff8801d94ea580 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 24 bytes to the right of 232-byte region [ffff8801d94ea580, ffff8801d94ea668) The buggy address belongs to the page: page:ffffea0007653a80 count:1 mapcount:0 mapping:ffff8801d94ea080 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d94ea080 0000000000000000 000000010000000c raw: ffffea0006b2e720 ffffea00076595e0 ffff8801d9450e40 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8801d94ea580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d94ea600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d94ea680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801d94ea700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d94ea780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================
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