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authorDavid S. Miller <davem@davemloft.net>2019-06-17 19:48:13 -0700
committerDavid S. Miller <davem@davemloft.net>2019-06-17 20:20:36 -0700
commit13091aa30535b719e269f20a7bc34002bf5afae5 (patch)
treebd17956c3ce606a119fadbd43bfa1c0c10006984 /kernel/cred.c
parentf97252a8c33f0e02f4ffbf61dc94cd38164007bc (diff)
parent29f785ff76b65696800b75c3d8e0b58e603bb1d0 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Honestly all the conflicts were simple overlapping changes, nothing really interesting to report. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/cred.c')
-rw-r--r--kernel/cred.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/cred.c b/kernel/cred.c
index e74ffdc98a92..c73a87a4df13 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -446,6 +446,15 @@ int commit_creds(struct cred *new)
if (task->mm)
set_dumpable(task->mm, suid_dumpable);
task->pdeath_signal = 0;
+ /*
+ * If a task drops privileges and becomes nondumpable,
+ * the dumpability change must become visible before
+ * the credential change; otherwise, a __ptrace_may_access()
+ * racing with this change may be able to attach to a task it
+ * shouldn't be able to attach to (as if the task had dropped
+ * privileges without becoming nondumpable).
+ * Pairs with a read barrier in __ptrace_may_access().
+ */
smp_wmb();
}