[syzbot] [bpf?] UBSAN: shift-out-of-bounds in adjust_reg_min_max_vals

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b1dfc0f76231 net: phy: skip LED triggers on PHYs on SFP mo..
git tree: net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=15d0331ee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e043d554f0a5f852
dashboard link: https://syzkaller.appspot.com/bug?extid=46700eea57ecc7f84776
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128c8ad1e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12456fb6e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fcd0802bfd92/disk-b1dfc0f7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d3d9e5ecc7f0/vmlinux-b1dfc0f7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4b04f82a5ed6/bzImage-b1dfc0f7.xz

The issue was bisected to:

commit f63181b6ae79fd3b034cde641db774268c2c3acf
Author: Andrii Nakryiko <and...@kernel.org>
Date: Fri Nov 4 16:36:47 2022 +0000

bpf: stop setting precise in current state

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10eed821e80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=12eed821e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=14eed821e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+46700e...@syzkaller.appspotmail.com
Fixes: f63181b6ae79 ("bpf: stop setting precise in current state")

================================================================================
UBSAN: shift-out-of-bounds in kernel/bpf/verifier.c:13571:63
shift exponent 1073741824 is too large for 32-bit type 'int'
CPU: 0 PID: 5069 Comm: syz-executor200 Not tainted 6.7.0-rc5-syzkaller-00167-gb1dfc0f76231 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_shift_out_of_bounds+0x2a6/0x480 lib/ubsan.c:387
scalar32_min_max_arsh kernel/bpf/verifier.c:13571 [inline]
adjust_scalar_min_max_vals kernel/bpf/verifier.c:13759 [inline]
adjust_reg_min_max_vals.cold+0x162/0x221 kernel/bpf/verifier.c:13860
check_alu_op+0x498/0x3a60 kernel/bpf/verifier.c:14092
do_check kernel/bpf/verifier.c:17517 [inline]
do_check_common+0x1b30/0xd690 kernel/bpf/verifier.c:20177
do_check_main kernel/bpf/verifier.c:20240 [inline]
bpf_check+0x77d9/0xa5e0 kernel/bpf/verifier.c:20877
bpf_prog_load+0x1531/0x2200 kernel/bpf/syscall.c:2716
__sys_bpf+0xbf7/0x4920 kernel/bpf/syscall.c:5383
__do_sys_bpf kernel/bpf/syscall.c:5487 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5485 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5485
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7ff0c7237af9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff01650e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff0c7237af9
RDX: 0000000000000048 RSI: 00000000200054c0 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000003a28
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
</TASK>
================================================================================


---
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[syzbot]

syzbot suspects this issue was fixed by commit:

commit 96381879a370425a30b810906946f64c0726450e
Author: Andrii Nakryiko <and...@kernel.org>
Date: Sun Nov 12 01:05:58 2023 +0000

bpf: generalize is_scalar_branch_taken() logic

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16e65a9fe80000
start commit: b1dfc0f76231 net: phy: skip LED triggers on PHYs on SFP mo..
git tree: net

kernel config: https://syzkaller.appspot.com/x/.config?x=e043d554f0a5f852
dashboard link: https://syzkaller.appspot.com/bug?extid=46700eea57ecc7f84776

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128c8ad1e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12456fb6e80000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: bpf: generalize is_scalar_branch_taken() logic

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.