linux-kernel - Re: [PATCH -next] arch/x86: Return value from notify

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 for Android: free password hash cracker in your pocket

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

Message-ID: <4d1ef78e-f001-a685-9a69-afa68454fdc7@oracle.com>
Date:   Mon, 22 Jun 2020 10:52:23 +0200
From:   Alexandre Chartre <alexandre.chartre@...cle.com>
To:     Bo YU <tsu.yubo@...il.com>, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, hpa@...or.com, peterz@...radead.org, luto@...nel.org,
        jannh@...gle.com, dave.hansen@...ux.intel.com
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH -next] arch/x86: Return value from notify_die should to be
 checked.


On 6/21/20 12:26 PM, Bo YU wrote:
> This is detected by Coverity scan: #CID: 1464472(CHECKED_RETURN)
> 
> FIXES: c94082656dac7(x86: Use enum instead of literals for trap values)
> Signed-off-by: Bo YU <tsu.yubo@...il.com>
> ---
> arch/x86/kernel/traps.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
> index af75109485c2..bf014fb59017 100644
> --- a/arch/x86/kernel/traps.c
> +++ b/arch/x86/kernel/traps.c
> @@ -401,7 +401,8 @@ DEFINE_IDTENTRY_DF(exc_double_fault)
> 
>      nmi_enter();
>      instrumentation_begin();
> -    notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
> +    if (notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV))
> +        return;
> 

This change is not correct, if there's a double fault then we should die even if
notify_die() fails. So the appropriate change to make Coverity happy is probably:

  (void) notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);

alex.