[PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve
From: Bernd Edlinger <hidden>
Date: 2020-03-10 17:45:22
Also in:
linux-doc, linux-fsdevel, linux-mm, lkml, stable
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2020-03-10 · Re: [PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve · Bernd Edlinger <hidden>
- 2020-03-10 · Re: [PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve · Eric W. Biederman <hidden>
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 <redacted> --- kernel/kcmp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index a0e3d7a..b3ff928 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c@@ -173,8 +173,8 @@ static int kcmp_epoll_target(struct task_struct *task1, /* * 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 @@ static int kcmp_epoll_target(struct task_struct *task1, } 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);
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1.9.1