Subject: [syzbot] WARNING in bpf_xdp_adjust_tail (4)

From: syzbot <[email-masked]>
Date: Mon, 09 Jan 2023 10:08:45 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    fe69230f0589 caif: fix memory leak in cfctrl_linkup_reques..
git tree:       net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=135e909a480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8ca07260bb631fb4
dashboard link: https://syzkaller.appspot.com/bug?extid=f817490f5bd20541b90a
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=11a3f770480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16d48034480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50a413c711d8/disk-fe69230f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b754ff4c853/vmlinux-fe69230f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1cef7470412e/bzImage-fe69230f.xz

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

------------[ cut here ]------------
Too BIG xdp->frame_sz = 131072
WARNING: CPU: 1 PID: 5082 at net/core/filter.c:4065 ____bpf_xdp_adjust_tail net/core/filter.c:4065 [inline]
WARNING: CPU: 1 PID: 5082 at net/core/filter.c:4065 bpf_xdp_adjust_tail+0x461/0x9a0 net/core/filter.c:4047
Modules linked in:
CPU: 1 PID: 5082 Comm: syz-executor157 Not tainted 6.1.0-syzkaller-04386-gfe69230f0589 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:____bpf_xdp_adjust_tail net/core/filter.c:4065 [inline]
RIP: 0010:bpf_xdp_adjust_tail+0x461/0x9a0 net/core/filter.c:4047
Code: ff 89 de e8 11 74 af f9 84 db 0f 85 59 fd ff ff e8 94 77 af f9 89 ee 48 c7 c7 c0 df 5b 8b c6 05 9c dc 8b 06 01 e8 9f 37 ed 01 <0f> 0b e9 38 fd ff ff e8 43 78 fd f9 e9 64 fc ff ff e8 39 78 fd f9
RSP: 0018:ffffc90003baf8f0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888029903a80 RSI: ffffffff8166721c RDI: fffff52000775f10
RBP: 0000000000020000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000000 R12: ffffffffffffffea
R13: ffff888076aafeef R14: 0000000000000000 R15: ffffc90003bafaa8
FS:  00005555573ed300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020011000 CR3: 000000007daac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bpf_prog_4add87e5301a4105+0x1a/0x1c
 __bpf_prog_run include/linux/filter.h:600 [inline]
 bpf_prog_run_xdp include/linux/filter.h:775 [inline]
 bpf_prog_run_generic_xdp+0x578/0x11e0 net/core/dev.c:4752
 netif_receive_generic_xdp+0x2e8/0x930 net/core/dev.c:4838
 do_xdp_generic net/core/dev.c:4897 [inline]
 do_xdp_generic+0x9a/0x1b0 net/core/dev.c:4890
 tun_get_user+0x21ae/0x3870 drivers/net/tun.c:1913
 tun_chr_write_iter+0xdf/0x200 drivers/net/tun.c:2029
 call_write_iter include/linux/fs.h:2186 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9ed/0xdd0 fs/read_write.c:584
 ksys_write+0x12b/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4723af0c33
Code: 5d 41 5c 41 5d 41 5e e9 9b fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 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:00007ffee97bbf18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffee97bbf40 RCX: 00007f4723af0c33
RDX: 000000000000fdef RSI: 0000000020001600 RDI: 00000000000000c8
RBP: 00007ffee97bbfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffee97bbf50 R14: 00007ffee97bbf70 R15: 00007ffee97bbf38
 </TASK>

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email-masked].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches