From b103c59883f1ec6e4d548b25054608cb5724453c Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:11 +1100 Subject: [PATCH] CRED: Wrap task credential accesses in the capabilities code Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells Reviewed-by: James Morris Acked-by: Serge Hallyn Cc: Andrew G. Morgan Signed-off-by: James Morris --- security/commoncap.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index dc06c0086b5..8283271f076 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -362,7 +362,7 @@ int cap_bprm_set_security (struct linux_binprm *bprm) * If only the real uid is 0, we do not set the effective * bit. */ - if (bprm->e_uid == 0 || current->uid == 0) { + if (bprm->e_uid == 0 || current_uid() == 0) { /* pP' = (cap_bset & ~0) | (pI & ~0) */ bprm->cap_post_exec_permitted = cap_combine( current->cap_bset, current->cap_inheritable @@ -379,8 +379,12 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) { kernel_cap_t pP = current->cap_permitted; kernel_cap_t pE = current->cap_effective; + uid_t uid; + gid_t gid; - if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || + current_uid_gid(&uid, &gid); + + if (bprm->e_uid != uid || bprm->e_gid != gid || !cap_issubset(bprm->cap_post_exec_permitted, current->cap_permitted)) { set_dumpable(current->mm, suid_dumpable); @@ -388,8 +392,8 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { if (!capable(CAP_SETUID)) { - bprm->e_uid = current->uid; - bprm->e_gid = current->gid; + bprm->e_uid = uid; + bprm->e_gid = gid; } if (cap_limit_ptraced_target()) { bprm->cap_post_exec_permitted = cap_intersect( @@ -437,15 +441,15 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) int cap_bprm_secureexec (struct linux_binprm *bprm) { - if (current->uid != 0) { + if (current_uid() != 0) { if (bprm->cap_effective) return 1; if (!cap_isclear(bprm->cap_post_exec_permitted)) return 1; } - return (current->euid != current->uid || - current->egid != current->gid); + return (current_euid() != current_uid() || + current_egid() != current_gid()); } int cap_inode_setxattr(struct dentry *dentry, const char *name, @@ -508,16 +512,18 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) static inline void cap_emulate_setxuid (int old_ruid, int old_euid, int old_suid) { + uid_t euid = current_euid(); + if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && - (current->uid != 0 && current->euid != 0 && current->suid != 0) && + (current_uid() != 0 && euid != 0 && current_suid() != 0) && !issecure(SECURE_KEEP_CAPS)) { cap_clear (current->cap_permitted); cap_clear (current->cap_effective); } - if (old_euid == 0 && current->euid != 0) { + if (old_euid == 0 && euid != 0) { cap_clear (current->cap_effective); } - if (old_euid != 0 && current->euid == 0) { + if (old_euid != 0 && euid == 0) { current->cap_effective = current->cap_permitted; } } @@ -546,12 +552,12 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, */ if (!issecure (SECURE_NO_SETUID_FIXUP)) { - if (old_fsuid == 0 && current->fsuid != 0) { + if (old_fsuid == 0 && current_fsuid() != 0) { current->cap_effective = cap_drop_fs_set( current->cap_effective); } - if (old_fsuid != 0 && current->fsuid == 0) { + if (old_fsuid != 0 && current_fsuid() == 0) { current->cap_effective = cap_raise_fs_set( current->cap_effective, -- 2.41.1