Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH 4.19 016/131] apparmor: don't try to replace stale label in ptraceme check | Date | Mon, 29 Jun 2020 11:33:07 -0400 |
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From: Jann Horn <jannh@google.com>
[ Upstream commit ca3fde5214e1d24f78269b337d3f22afd6bf445e ]
begin_current_label_crit_section() must run in sleepable context because when label_is_stale() is true, aa_replace_current_label() runs, which uses prepare_creds(), which can sleep.
Until now, the ptraceme access check (which runs with tasklist_lock held) violated this rule.
Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels") Reported-by: Cyrill Gorcunov <gorcunov@gmail.com> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- security/apparmor/lsm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 5e32fe434140e..898752b818dc5 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -130,11 +130,11 @@ static int apparmor_ptrace_traceme(struct task_struct *parent) struct aa_label *tracer, *tracee; int error; - tracee = begin_current_label_crit_section(); + tracee = __begin_current_label_crit_section(); tracer = aa_get_task_label(parent); error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE); aa_put_label(tracer); - end_current_label_crit_section(tracee); + __end_current_label_crit_section(tracee); return error; } -- 2.25.1
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