* [PATCH] PCI: Always initialize dev in pciconfig_read
@ 2021-08-03 20:08 Nathan Chancellor
2021-08-03 21:56 ` Bjorn Helgaas
2021-08-03 23:09 ` Krzysztof Wilczyński
0 siblings, 2 replies; 3+ messages in thread
From: Nathan Chancellor @ 2021-08-03 20:08 UTC (permalink / raw)
To: Bjorn Helgaas, Krzysztof Wilczyński
Cc: Nick Desaulniers, linux-pci, linux-kernel, clang-built-linux,
Nathan Chancellor
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>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: Always initialize dev in pciconfig_read
2021-08-03 20:08 [PATCH] PCI: Always initialize dev in pciconfig_read Nathan Chancellor
@ 2021-08-03 21:56 ` Bjorn Helgaas
2021-08-03 23:09 ` Krzysztof Wilczyński
1 sibling, 0 replies; 3+ messages in thread
From: Bjorn Helgaas @ 2021-08-03 21:56 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Bjorn Helgaas, Krzysztof Wilczyński, Nick Desaulniers,
linux-pci, linux-kernel, clang-built-linux
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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: Always initialize dev in pciconfig_read
2021-08-03 20:08 [PATCH] PCI: Always initialize dev in pciconfig_read Nathan Chancellor
2021-08-03 21:56 ` Bjorn Helgaas
@ 2021-08-03 23:09 ` Krzysztof Wilczyński
1 sibling, 0 replies; 3+ messages in thread
From: Krzysztof Wilczyński @ 2021-08-03 23:09 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Bjorn Helgaas, Nick Desaulniers, linux-pci, linux-kernel,
clang-built-linux
Hi Nathan,
> drivers/pci/syscall.c:18:21: note: initialize the variable 'dev' to
> silence this warning
> struct pci_dev *dev;
> ^
> = NULL
[...]
Nice catch! Thank you for fixing and sorry that I miss this one!
Krzysztof
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-08-03 20:08 [PATCH] PCI: Always initialize dev in pciconfig_read Nathan Chancellor
2021-08-03 21:56 ` Bjorn Helgaas
2021-08-03 23:09 ` Krzysztof Wilczyński
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