From: Bjorn Helgaas <helgaas@kernel.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: "Bjorn Helgaas" <bhelgaas@google.com>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Nick Desaulniers" <ndesaulniers@google.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com
Subject: Re: [PATCH] PCI: Always initialize dev in pciconfig_read
Date: Tue, 3 Aug 2021 16:56:21 -0500 [thread overview]
Message-ID: <20210803215621.GA1576408@bjorn-Precision-5520> (raw)
In-Reply-To: <20210803200836.500658-1-nathan@kernel.org>
On Tue, Aug 03, 2021 at 01:08:36PM -0700, Nathan Chancellor wrote:
> Clang warns:
>
> drivers/pci/syscall.c:25:6: warning: variable 'dev' is used
> uninitialized whenever 'if' condition is true
> [-Wsometimes-uninitialized]
> if (!capable(CAP_SYS_ADMIN))
> ^~~~~~~~~~~~~~~~~~~~~~~
> drivers/pci/syscall.c:81:14: note: uninitialized use occurs here
> pci_dev_put(dev);
> ^~~
> drivers/pci/syscall.c:25:2: note: remove the 'if' if its condition is
> always false
> if (!capable(CAP_SYS_ADMIN))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/pci/syscall.c:18:21: note: initialize the variable 'dev' to
> silence this warning
> struct pci_dev *dev;
> ^
> = NULL
> 1 warning generated.
>
> pci_dev_put accounts for a NULL pointer so initialize dev to NULL before
> the capability check so that there is no use of uninitialized memory.
>
> Fixes: 61a6199787d9 ("PCI: Return ~0 data on pciconfig_read() CAP_SYS_ADMIN failure")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Squashed in locally, thanks!
> ---
> drivers/pci/syscall.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c
> index 525f16caed1d..61a6fe3cde21 100644
> --- a/drivers/pci/syscall.c
> +++ b/drivers/pci/syscall.c
> @@ -22,6 +22,7 @@ SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
> int err, cfg_ret;
>
> err = -EPERM;
> + dev = NULL;
> if (!capable(CAP_SYS_ADMIN))
> goto error;
>
>
> base-commit: 21d8e94253eb09f7c94c4db00dc714efc75b8701
> --
> 2.33.0.rc0
>
next prev parent reply other threads:[~2021-08-03 21:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-03 20:08 [PATCH] PCI: Always initialize dev in pciconfig_read Nathan Chancellor
2021-08-03 21:56 ` Bjorn Helgaas [this message]
2021-08-03 23:09 ` Krzysztof Wilczyński
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