Messages in this thread Patch in this message | | | Date | Tue, 27 Sep 2011 21:56:42 +0400 | From | Vasiliy Kulikov <> | Subject | [PATCH 2/2] mm: restrict access to /proc/meminfo |
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/proc/meminfo stores information related to memory pages usage, which may be used to monitor the number of objects in specific caches (and/or the changes of these numbers). This might reveal private information similar to /proc/slabinfo infoleaks. To remove the infoleak, just restrict meminfo to root. If it is used by unprivileged daemons, meminfo permissions can be altered the same way as slabinfo:
groupadd meminfo usermod -a -G meminfo $MONITOR_USER chmod g+r /proc/meminfo chgrp meminfo /proc/meminfo
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> CC: Kees Cook <kees@ubuntu.com> CC: Dave Hansen <dave@linux.vnet.ibm.com> CC: Christoph Lameter <cl@gentwo.org> CC: Pekka Enberg <penberg@cs.helsinki.fi> CC: Valdis.Kletnieks@vt.edu CC: Linus Torvalds <torvalds@linux-foundation.org> CC: David Rientjes <rientjes@google.com> CC: Alan Cox <alan@linux.intel.com> --- fs/proc/meminfo.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
-- diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 5861741..949bdee 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -187,7 +187,7 @@ static const struct file_operations meminfo_proc_fops = { static int __init proc_meminfo_init(void) { - proc_create("meminfo", 0, NULL, &meminfo_proc_fops); + proc_create("meminfo", S_IFREG | S_IRUSR, NULL, &meminfo_proc_fops); return 0; } module_init(proc_meminfo_init);
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