lkml.org 
[lkml]   [2019]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] powerpc/mm: don't log user reads to 0xffffffff
Date
Running vdsotest leaves many times the following log:

[ 79.629901] vdsotest[396]: User access of kernel address (ffffffff) - exploit attempt? (uid: 0)

A pointer set to (-1) is likely a programming error similar to
a NULL pointer and is not worth logging as an exploit attempt.

Don't log user accesses to 0xffffffff.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/mm/fault.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index b5047f9b5dec..d3b4d444bf3c 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -354,6 +354,9 @@ static void sanity_check_fault(bool is_write, bool is_user,
* Userspace trying to access kernel address, we get PROTFAULT for that.
*/
if (is_user && address >= TASK_SIZE) {
+ if ((long)address == -1)
+ return;
+
pr_crit_ratelimited("%s[%d]: User access of kernel address (%lx) - exploit attempt? (uid: %d)\n",
current->comm, current->pid, address,
from_kuid(&init_user_ns, current_uid()));
--
2.13.3
\
 
 \ /
  Last update: 2019-12-23 08:55    [W:0.023 / U:8.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site