Message-ID: <00000000000088694505f8132d77@google.com>
Date:   Wed, 29 Mar 2023 17:28:55 -0700
From:   syzbot <syzbot+8ac3859139c685c4f597@...kaller.appspotmail.com>
To:     brauner@...nel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com,
        viro@...iv.linux.org.uk
Subject: [syzbot] [fs?] KASAN: null-ptr-deref Read in ida_free (3)

Hello,

syzbot found the following issue on:

HEAD commit:    da8e7da11e4b Merge tag 'nfsd-6.3-4' of git://git.kernel.or..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1266331ec80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=acdb62bf488a8fe5
dashboard link: https://syzkaller.appspot.com/bug?extid=8ac3859139c685c4f597
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11639815c80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12128b1ec80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/62e9c5f4bead/disk-da8e7da1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c11aa933e2a7/vmlinux-da8e7da1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7a21bdd49c84/bzImage-da8e7da1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ac3859139c685c4f597@...kaller.appspotmail.com

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: null-ptr-deref in ida_free+0x1b9/0x400 lib/idr.c:511
Read of size 8 at addr 0000000000000000 by task syz-executor237/5830

CPU: 1 PID: 5830 Comm: syz-executor237 Not tainted 6.3.0-rc3-syzkaller-00338-gda8e7da11e4b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_report+0xe6/0x540 mm/kasan/report.c:433
 kasan_report+0x176/0x1b0 mm/kasan/report.c:536
 kasan_check_range+0x283/0x290 mm/kasan/generic.c:187
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 ida_free+0x1b9/0x400 lib/idr.c:511
 mnt_release_group_id fs/namespace.c:160 [inline]
 cleanup_group_ids fs/namespace.c:2093 [inline]
 do_mount_setattr fs/namespace.c:4188 [inline]
 __do_sys_mount_setattr fs/namespace.c:4375 [inline]
 __se_sys_mount_setattr+0xc44/0x1b00 fs/namespace.c:4334
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7efc4b190919
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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:00007efc4b142318 EFLAGS: 00000246 ORIG_RAX: 00000000000001ba
RAX: ffffffffffffffda RBX: 00007efc4b2183e8 RCX: 00007efc4b190919
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007efc4b2183e0 R08: 0000000000000020 R09: 0000000000000000
R10: 0000000020000140 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffe5a122bdf R14: 00007efc4b142400 R15: 0000000000022000
 </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 syzkaller@...glegroups.com.

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

Powered by blists - more mailing lists