The commit is pushed to "branch-rh8-4.18.0-193.6.3.vz8.4.x-ovz" and will appear
at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-193.6.3.vz8.4.9
------>
commit 56a5186d29d7373d71fd1519d90b785585840a2f
Author: Randy Dunlap <[email protected]>
Date: Wed Apr 1 21:10:58 2020 -0700
ms/mm: mempolicy: require at least one nodeid for MPOL_PREFERRED
Using an empty (malformed) nodelist that is not caught during mount option
parsing leads to a stack-out-of-bounds access.
The option string that was used was: "mpol=prefer:,". However,
MPOL_PREFERRED requires a single node number, which is not being provided
here.
Add a check that 'nodes' is not empty after parsing for MPOL_PREFERRED's
nodeid.
Fixes: 095f1fc4ebf3 ("mempolicy: rework shmem mpol parsing and display")
Reported-by: Entropy Moe <[email protected]>
Reported-by: [email protected]
Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Tested-by: [email protected]
Cc: Lee Schermerhorn <[email protected]>
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
https://jira.sw.ru/browse/PSBM-120642
CVE-2020-11565: out-of-bounds write in mpol_parse_str function in
mm/mempolicy.c
(cherry picked from commit aa9f7d5172fac9bf1f09e678c35e287a40a7b7dd)
Signed-off-by: Konstantin Khorenko <[email protected]>
---
mm/mempolicy.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index dab3b16534f0..b24738101414 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2797,7 +2797,9 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
switch (mode) {
case MPOL_PREFERRED:
/*
- * Insist on a nodelist of one node only
+ * Insist on a nodelist of one node only, although later
+ * we use first_node(nodes) to grab a single node, so here
+ * nodelist (or nodes) cannot be empty.
*/
if (nodelist) {
char *rest = nodelist;
@@ -2805,6 +2807,8 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
rest++;
if (*rest)
goto out;
+ if (nodes_empty(nodes))
+ goto out;
}
break;
case MPOL_INTERLEAVE:
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