diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2025-02-19 17:14:17 +0100 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2025-03-07 19:58:05 -0800 |
| commit | 71c769231ff73289c8f988453987af60f1d04da3 (patch) | |
| tree | 3e49e63247ab50446f35cf48df04d40c2522382b | |
| parent | a3aac126ca3a71b6612a817ef24db325618fd902 (diff) | |
| download | linux-71c769231ff73289c8f988453987af60f1d04da3.tar.gz linux-71c769231ff73289c8f988453987af60f1d04da3.tar.bz2 linux-71c769231ff73289c8f988453987af60f1d04da3.zip | |
yama: don't abuse rcu_read_lock/get_task_struct in yama_task_prctl()
current->group_leader is stable, no need to take rcu_read_lock() and do
get/put_task_struct().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250219161417.GA20851@redhat.com
Signed-off-by: Kees Cook <kees@kernel.org>
| -rw-r--r-- | security/yama/yama_lsm.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 1971710620c1..3d064dd4e03f 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -222,7 +222,7 @@ static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { int rc = -ENOSYS; - struct task_struct *myself = current; + struct task_struct *myself; switch (option) { case PR_SET_PTRACER: @@ -232,11 +232,7 @@ static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, * leader checking is handled later when walking the ancestry * at the time of PTRACE_ATTACH check. */ - rcu_read_lock(); - if (!thread_group_leader(myself)) - myself = rcu_dereference(myself->group_leader); - get_task_struct(myself); - rcu_read_unlock(); + myself = current->group_leader; if (arg2 == 0) { yama_ptracer_del(NULL, myself); @@ -255,7 +251,6 @@ static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, } } - put_task_struct(myself); break; } |