Subject: [syzbot] KASAN: vmalloc-out-of-bounds Read in bpf_jit_free

From: syzbot <[email-masked]>
Date: Mon, 14 Feb 2022 10:45:19 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    e5313968c41b Merge branch 'Split bpf_sk_lookup remote_port..
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10baced8700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c40b67275bfe2a58
dashboard link: https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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]

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in bpf_jit_binary_pack_free kernel/bpf/core.c:1120 [inline]
BUG: KASAN: vmalloc-out-of-bounds in bpf_jit_free+0x2b5/0x2e0 kernel/bpf/core.c:1151
Read of size 4 at addr ffffffffa0001a80 by task kworker/0:18/13642

CPU: 0 PID: 13642 Comm: kworker/0:18 Not tainted 5.16.0-syzkaller-11655-ge5313968c41b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events bpf_prog_free_deferred
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xf/0x336 mm/kasan/report.c:255
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 bpf_jit_binary_pack_free kernel/bpf/core.c:1120 [inline]
 bpf_jit_free+0x2b5/0x2e0 kernel/bpf/core.c:1151
 bpf_prog_free_deferred+0x5c1/0x790 kernel/bpf/core.c:2524
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Memory state around the buggy address:
 ffffffffa0001980: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffffffa0001a00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffffffa0001a80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffffffa0001b00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffffffa0001b80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

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