From eb2d55a32b9a91bca0dea299eedb560bafa8b14e Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Jun 2010 22:43:32 +0200 Subject: [PATCH] rlimits: selinux, do rlimits changes under task_lock When doing an exec, selinux updates rlimits in its code of current process depending on current max. Make sure max or cur doesn't change in the meantime by grabbing task_lock which do_prlimit needs for changing limits too. While at it, use rlimit helper for accessing CPU rlimit a line below. To have a volatile access too. Signed-off-by: Jiri Slaby Cc: Oleg Nesterov --- security/selinux/hooks.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index afb18a9ebba1..2a8a0a915ff3 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2333,13 +2333,15 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm) rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, PROCESS__RLIMITINH, NULL); if (rc) { + /* protect against do_prlimit() */ + task_lock(current); for (i = 0; i < RLIM_NLIMITS; i++) { rlim = current->signal->rlim + i; initrlim = init_task.signal->rlim + i; rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); } - update_rlimit_cpu(current, - current->signal->rlim[RLIMIT_CPU].rlim_cur); + task_unlock(current); + update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); } } -- GitLab