Messages in this thread Patch in this message | | | From | Bernd Edlinger <> | Subject | [PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve | Date | Tue, 10 Mar 2020 18:45:11 +0100 |
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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> --- 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); -- 1.9.1
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