* [PATCH] sysctl: don't read uninit memory in deprecated_sysctl_warning()
@ 2017-06-28 15:00 Alexander Potapenko
2017-06-29 22:32 ` Andrew Morton
0 siblings, 1 reply; 2+ messages in thread
From: Alexander Potapenko @ 2017-06-28 15:00 UTC (permalink / raw)
To: dvyukov, kcc, davem, akpm; +Cc: linux-kernel
Don't attempt to read the first two elements of name[] unless they
were actually copied from the userspace.
This bug has been detected by KMSAN.
Signed-off-by: Alexander Potapenko <glider@google.com>
---
kernel/sysctl_binary.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index ece4b177052b..38d6ba22a209 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1346,7 +1346,7 @@ static void deprecated_sysctl_warning(const int *name, int nlen)
* CTL_KERN/KERN_VERSION is used by older glibc and cannot
* ever go away.
*/
- if (name[0] == CTL_KERN && name[1] == KERN_VERSION)
+ if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
return;
if (printk_ratelimit()) {
--
2.13.2.725.g09c95d1e9-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] sysctl: don't read uninit memory in deprecated_sysctl_warning()
2017-06-28 15:00 [PATCH] sysctl: don't read uninit memory in deprecated_sysctl_warning() Alexander Potapenko
@ 2017-06-29 22:32 ` Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2017-06-29 22:32 UTC (permalink / raw)
To: Alexander Potapenko; +Cc: dvyukov, kcc, davem, linux-kernel, Mateusz Jurczyk
On Wed, 28 Jun 2017 17:00:37 +0200 Alexander Potapenko <glider@google.com> wrote:
> Don't attempt to read the first two elements of name[] unless they
> were actually copied from the userspace.
>
> This bug has been detected by KMSAN.
Thanks. I already have the identical
http://ozlabs.org/~akpm/mmots/broken-out/sysctl-check-name-array-length-in-deprecated_sysctl_warning.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-06-28 15:00 [PATCH] sysctl: don't read uninit memory in deprecated_sysctl_warning() Alexander Potapenko
2017-06-29 22:32 ` Andrew Morton
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