Subject: Re: [syzbot] WARNING in bpf_prog_test_run_xdp

From: syzbot <[email-masked]>
Date: Wed, 02 Feb 2022 15:12:19 -0800

syzbot has found a reproducer for the following issue on:

HEAD commit:    dd5152ab338c Merge branch 'bpf-btf-dwarf5'
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=138d300c700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b210f94c3ec14b22
dashboard link: https://syzkaller.appspot.com/bug?extid=79fd1ab62b382be6f337
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17d37f00700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14745624700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 3596 at include/linux/thread_info.h:230 check_copy_size include/linux/thread_info.h:230 [inline]
WARNING: CPU: 1 PID: 3596 at include/linux/thread_info.h:230 copy_from_user include/linux/uaccess.h:191 [inline]
WARNING: CPU: 1 PID: 3596 at include/linux/thread_info.h:230 bpf_prog_test_run_xdp+0xec7/0x1150 net/bpf/test_run.c:978
Modules linked in:
CPU: 1 PID: 3596 Comm: syz-executor589 Not tainted 5.16.0-syzkaller-11587-gdd5152ab338c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_copy_size include/linux/thread_info.h:230 [inline]
RIP: 0010:copy_from_user include/linux/uaccess.h:191 [inline]
RIP: 0010:bpf_prog_test_run_xdp+0xec7/0x1150 net/bpf/test_run.c:978
Code: fd 06 48 c1 e5 0c 48 01 c5 e8 b5 71 0d fa 49 81 fe ff ff ff 7f 0f 86 08 fe ff ff 4c 8b 74 24 60 4c 8b 7c 24 68 e8 09 6f 0d fa <0f> 0b 41 bc f2 ff ff ff e9 02 fb ff ff 4c 8b 74 24 60 4c 8b 7c 24
RSP: 0018:ffffc90002acfb40 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000fffff0de RCX: 0000000000000000
RDX: ffff88801ad5ba00 RSI: ffffffff876ae697 RDI: 0000000000000003
RBP: ffff88801e32b000 R08: 000000007fffffff R09: ffffffff8d9399d7
R10: ffffffff876ae67b R11: 000000000000001f R12: 0000000000000dc0
R13: ffff888019342000 R14: 0000000000000000 R15: ffffc90000d6e000
FS:  00005555560c8300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000280 CR3: 000000001df60000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bpf_prog_test_run kernel/bpf/syscall.c:3356 [inline]
 __sys_bpf+0x1858/0x59a0 kernel/bpf/syscall.c:4658
 __do_sys_bpf kernel/bpf/syscall.c:4744 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4742 [inline]
 __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4742
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd2338db1d9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd14e00248 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd2338db1d9
RDX: 0000000000000048 RSI: 00000000200013c0 RDI: 000000000000000a
RBP: 00007fd23389f1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd23389f250
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>