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authorBernd Edlinger <bernd.edlinger@hotmail.de>2020-03-20 21:27:05 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-01 13:17:48 +0200
commit0cd97836869e9792cd66a2223b978f0148b46a12 (patch)
tree85f85778affb35118835f958fbecc56f9829f6e9 /kernel
parent2f7a0de4e5da7223902d48a30833bc67ef45a02b (diff)
kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve
[ Upstream commit 454e3126cb842388e22df6b3ac3da44062c00765 ] This changes kcmp_epoll_target to use the new exec_update_mutex instead of cred_guard_mutex. This should be safe, as the credentials are only used for reading, and furthermore ->mm and ->sighand are updated on execve, but only under the new exec_update_mutex. Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kcmp.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index a0e3d7a0e8b8..b3ff9288c6cc 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c
@@ -173,8 +173,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
/*
* One should have enough rights to inspect task details.
*/
- ret = kcmp_lock(&task1->signal->cred_guard_mutex,
- &task2->signal->cred_guard_mutex);
+ ret = kcmp_lock(&task1->signal->exec_update_mutex,
+ &task2->signal->exec_update_mutex);
if (ret)
goto err;
if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) ||
@@ -229,8 +229,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
}
err_unlock:
- kcmp_unlock(&task1->signal->cred_guard_mutex,
- &task2->signal->cred_guard_mutex);
+ kcmp_unlock(&task1->signal->exec_update_mutex,
+ &task2->signal->exec_update_mutex);
err:
put_task_struct(task1);
put_task_struct(task2);