From: syzbot <syzbot+79fcba037b6df73756d3@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, postmaster@duagon.onmicrosoft.com,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [mm?] WARNING: suspicious RCU usage in mas_walk (3)
Date: Mon, 23 Oct 2023 10:24:48 -0700 [thread overview]
Message-ID: <000000000000c05f1b0608657fde@google.com> (raw)
In-Reply-To: <000000000000985ef90607610b0a@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: e8361b005d7c Add linux-next specific files for 20231023
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1207cb05680000
kernel config: https://syzkaller.appspot.com/x/.config?x=75e8fc3570ec9a74
dashboard link: https://syzkaller.appspot.com/bug?extid=79fcba037b6df73756d3
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=107fab89680000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e28a7944599e/disk-e8361b00.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7dd355dbe055/vmlinux-e8361b00.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7b2a9050635d/bzImage-e8361b00.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+79fcba037b6df73756d3@syzkaller.appspotmail.com
=============================
WARNING: suspicious RCU usage
6.6.0-rc6-next-20231023-syzkaller #0 Not tainted
-----------------------------
lib/maple_tree.c:856 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by syz-executor.4/5222.
stack backtrace:
CPU: 0 PID: 5222 Comm: syz-executor.4 Not tainted 6.6.0-rc6-next-20231023-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
lockdep_rcu_suspicious+0x20b/0x3a0 kernel/locking/lockdep.c:6711
mas_root lib/maple_tree.c:856 [inline]
mas_root lib/maple_tree.c:854 [inline]
mas_start lib/maple_tree.c:1385 [inline]
mas_state_walk lib/maple_tree.c:3705 [inline]
mas_walk+0x4d1/0x7d0 lib/maple_tree.c:4888
mas_find_setup lib/maple_tree.c:5948 [inline]
mas_find+0x1e6/0x400 lib/maple_tree.c:5989
vma_find include/linux/mm.h:952 [inline]
do_mbind+0xc8f/0x1010 mm/mempolicy.c:1328
kernel_mbind+0x1d4/0x1f0 mm/mempolicy.c:1486
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7f9979c7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9978ffe0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007f9979d9c050 RCX: 00007f9979c7cae9
RDX: 0000000000000003 RSI: 0000000000005000 RDI: 0000000020182000
RBP: 00007f9979cc847a R08: 000000000000007f R09: 0000000000000003
R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f9979d9c050 R15: 00007ffdbdd465f8
</TASK>
=============================
WARNING: suspicious RCU usage
6.6.0-rc6-next-20231023-syzkaller #0 Not tainted
-----------------------------
lib/maple_tree.c:812 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by syz-executor.4/5222.
stack backtrace:
CPU: 0 PID: 5222 Comm: syz-executor.4 Not tainted 6.6.0-rc6-next-20231023-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
lockdep_rcu_suspicious+0x20b/0x3a0 kernel/locking/lockdep.c:6711
mt_slot lib/maple_tree.c:812 [inline]
mt_slot lib/maple_tree.c:809 [inline]
mtree_range_walk+0x6c5/0x9b0 lib/maple_tree.c:2827
mas_state_walk lib/maple_tree.c:3712 [inline]
mas_walk+0x374/0x7d0 lib/maple_tree.c:4888
mas_find_setup lib/maple_tree.c:5948 [inline]
mas_find+0x1e6/0x400 lib/maple_tree.c:5989
vma_find include/linux/mm.h:952 [inline]
do_mbind+0xc8f/0x1010 mm/mempolicy.c:1328
kernel_mbind+0x1d4/0x1f0 mm/mempolicy.c:1486
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7f9979c7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9978ffe0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007f9979d9c050 RCX: 00007f9979c7cae9
RDX: 0000000000000003 RSI: 0000000000005000 RDI: 0000000020182000
RBP: 00007f9979cc847a R08: 000000000000007f R09: 0000000000000003
R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f9979d9c050 R15: 00007ffdbdd465f8
</TASK>
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
next prev parent reply other threads:[~2023-10-23 17:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-10 18:40 [syzbot] [mm?] WARNING: suspicious RCU usage in mas_walk (3) syzbot
2023-10-23 17:24 ` syzbot [this message]
2023-10-23 17:55 ` Liam R. Howlett
2023-10-23 20:21 ` Hugh Dickins
2023-10-24 9:31 ` syzbot
2023-10-25 0:07 ` syzbot
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