Subject: [syzbot] UBSAN: shift-out-of-bounds in ___bpf_prog_run

From: syzbot <[email-masked]>
Date: Wed, 10 Mar 2021 08:05:22 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    144c79ef Merge tag 'perf-tools-fixes-for-v5.12-2020-03-07'..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1572d952d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ccdd84f79f45b23d
dashboard link: https://syzkaller.appspot.com/bug?extid=bed360704c521841c85d

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

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

================================================================================
UBSAN: shift-out-of-bounds in kernel/bpf/core.c:1420:2
shift exponent 255 is too large for 64-bit type 'long long unsigned int'
CPU: 1 PID: 11097 Comm: syz-executor.4 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327
 ___bpf_prog_run.cold+0x19/0x56c kernel/bpf/core.c:1420
 __bpf_prog_run32+0x8f/0xd0 kernel/bpf/core.c:1735
 bpf_dispatcher_nop_func include/linux/bpf.h:644 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:624 [inline]
 bpf_prog_run_clear_cb include/linux/filter.h:755 [inline]
 run_filter+0x1a1/0x470 net/packet/af_packet.c:2031
 packet_rcv+0x313/0x13e0 net/packet/af_packet.c:2104
 dev_queue_xmit_nit+0x7c2/0xa90 net/core/dev.c:2387
 xmit_one net/core/dev.c:3588 [inline]
 dev_hard_start_xmit+0xad/0x920 net/core/dev.c:3609
 __dev_queue_xmit+0x2121/0x2e00 net/core/dev.c:4182
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2141 [inline]
 __bpf_redirect+0x548/0xc80 net/core/filter.c:2164
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x2ae/0x420 net/core/filter.c:2420
 ___bpf_prog_run+0x34e1/0x77d0 kernel/bpf/core.c:1523
 __bpf_prog_run512+0x99/0xe0 kernel/bpf/core.c:1737
 bpf_dispatcher_nop_func include/linux/bpf.h:644 [inline]
 bpf_test_run+0x3ed/0xc50 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0xabc/0x1c50 net/bpf/test_run.c:582
 bpf_prog_test_run kernel/bpf/syscall.c:3127 [inline]
 __do_sys_bpf+0x1ea9/0x4f00 kernel/bpf/syscall.c:4406
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465f69
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2797f63188 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69
RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
RBP: 00000000004bfa3f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffcd53d929f R14: 00007f2797f63300 R15: 0000000000022000
================================================================================

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