linux-kernel - Re: [PATCH] MIPS: scall64-o32: Fix indirect syscall number load

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>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <MWHPR2201MB12779DF3BC8AEC1203A65065C12B0@MWHPR2201MB1277.namprd22.prod.outlook.com>
Date:   Mon, 15 Apr 2019 17:36:58 +0000
From:   Paul Burton <paul.burton@...s.com>
To:     Aurelien Jarno <aurelien@...el32.net>
CC:     Ralf Baechle <ralf@...ux-mips.org>,
        Paul Burton <pburton@...ecomp.com>,
        James Hogan <jhogan@...nel.org>,
        "linux-mips@...r.kernel.org" <linux-mips@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Aurelien Jarno <aurelien@...el32.net>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "linux-mips@...r.kernel.org" <linux-mips@...r.kernel.org>
Subject: Re: [PATCH] MIPS: scall64-o32: Fix indirect syscall number load

Hello,

Aurelien Jarno wrote:
> Commit 4c21b8fd8f14 (MIPS: seccomp: Handle indirect system calls (o32))
> added indirect syscall detection for O32 processes running on MIPS64,
> but it did not work correctly for big endian kernel/processes. The
> reason is that the syscall number is loaded from ARG1 using the lw
> instruction while this is a 64-bit value, so zero is loaded instead of
> the syscall number.
> 
> Fix the code by using the ld instruction instead. When running a 32-bit
> processes on a 64 bit CPU, the values are properly sign-extended, so it
> ensures the value passed to syscall_trace_enter is correct.
> 
> Recent systemd versions with seccomp enabled whitelist the getpid
> syscall for their internal  processes (e.g. systemd-journald), but call
> it through syscall(SYS_getpid). This fix therefore allows O32 big endian
> systems with a 64-bit kernel to run recent systemd versions.
> 
> Signed-off-by: Aurelien Jarno <aurelien@...el32.net>
> Cc: <stable@...r.kernel.org> # v3.15+
> Reviewed-by: Philippe Mathieu-DaudÃ© <f4bug@...at.org>

Applied to mips-fixes.

Thanks,
    Paul

[ This message was auto-generated; if you believe anything is incorrect
  then please email paul.burton@...s.com to report it. ]