linux-kernel - [syzbot] BUG: using smp_processor_id() in preemptible code in __do_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <0000000000007604cb05bd3e6968@google.com>
Date:   Thu, 11 Mar 2021 00:17:18 -0800
From:   syzbot <syzbot+a7ee43e564223f195c84@...kaller.appspotmail.com>
To:     alexandre.chartre@...cle.com, bristot@...hat.com,
        linux-kernel@...r.kernel.org, peterz@...radead.org,
        syzkaller-bugs@...glegroups.com, tglx@...utronix.de,
        valentin.schneider@....com
Subject: [syzbot] BUG: using smp_processor_id() in preemptible code in __do_user_fault

Hello,

syzbot found the following issue on:

HEAD commit:    a74e6a01 Merge tag 's390-5.12-3' of git://git.kernel.org/p..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f67ae6d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c7ac5ce2d1160e16
dashboard link: https://syzkaller.appspot.com/bug?extid=a7ee43e564223f195c84
userspace arch: arm

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: syzbot+a7ee43e564223f195c84@...kaller.appspotmail.com

BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor.0/15841
caller is debug_smp_processor_id+0x20/0x24 lib/smp_processor_id.c:64
CPU: 0 PID: 15841 Comm: syz-executor.0 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace: 
[<82107738>] (dump_backtrace) from [<821079ac>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252)
 r7:00000000 r6:60000113 r5:00000000 r4:83966184
[<82107994>] (show_stack) from [<82110980>] (__dump_stack lib/dump_stack.c:79 [inline])
[<82107994>] (show_stack) from [<82110980>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120)
[<821108c8>] (dump_stack) from [<82133120>] (check_preemption_disabled+0x118/0x11c lib/smp_processor_id.c:53)
 r7:8294d26c r6:00000000 r5:82133144 r4:86d725b0
[<82133008>] (check_preemption_disabled) from [<82133144>] (debug_smp_processor_id+0x20/0x24 lib/smp_processor_id.c:64)
 r7:00000a07 r6:86d72080 r5:0000000b r4:ffffc000
[<82133124>] (debug_smp_processor_id) from [<80217a00>] (harden_branch_predictor arch/arm/include/asm/system_misc.h:24 [inline])
[<82133124>] (debug_smp_processor_id) from [<80217a00>] (__do_user_fault+0x98/0x108 arch/arm/mm/fault.c:142)
[<80217968>] (__do_user_fault) from [<80217c90>] (do_page_fault+0x190/0x378 arch/arm/mm/fault.c:357)
 r9:00000800 r8:84649ebc r7:84649e40 r6:00000a07 r5:ffffc000 r4:89063fb0
[<80217b00>] (do_page_fault) from [<80218054>] (do_DataAbort+0x38/0xb8 arch/arm/mm/fault.c:522)
 r10:7ef2f914 r9:76f276d0 r8:80217b00 r7:89063fb0 r6:ffffc000 r5:00000a07
 r4:83837b38
[<8021801c>] (do_DataAbort) from [<80200dc4>] (__dabt_usr+0x44/0x60 arch/arm/kernel/entry-armv.S:421)
Exception stack(0x89063fb0 to 0x89063ff8)
3fa0:                                     ffffff00 20000280 ffffc000 20000250
3fc0: 00000004 20070517 00000140 20ffb000 7ef2f79a 76f276d0 7ef2f914 76f2720c
3fe0: 00000000 76f27020 00000006 00013b18 80000010 ffffffff
 r8:30c5387d r7:30c5387d r6:ffffffff r5:80000010 r4:00013b18


---
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.