diff options
| -rw-r--r-- | security/selinux/avc.c | 36 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 26 | ||||
| -rw-r--r-- | security/selinux/include/avc.h | 18 |
3 files changed, 55 insertions, 25 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 9da6420e2056..1d027e29ce8d 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -471,6 +471,7 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a) * @avd: access vector decisions * @result: result from avc_has_perm_noaudit * @a: auxiliary audit data + * @flags: VFS walk flags * * Audit the granting or denial of permissions in accordance * with the policy. This function is typically called by @@ -481,9 +482,10 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a) * be performed under a lock, to allow the lock to be released * before calling the auditing code. */ -void avc_audit(u32 ssid, u32 tsid, +int avc_audit(u32 ssid, u32 tsid, u16 tclass, u32 requested, - struct av_decision *avd, int result, struct common_audit_data *a) + struct av_decision *avd, int result, struct common_audit_data *a, + unsigned flags) { struct common_audit_data stack_data; u32 denied, audited; @@ -515,11 +517,24 @@ void avc_audit(u32 ssid, u32 tsid, else audited = requested & avd->auditallow; if (!audited) - return; + return 0; + if (!a) { a = &stack_data; COMMON_AUDIT_DATA_INIT(a, NONE); } + + /* + * When in a RCU walk do the audit on the RCU retry. This is because + * the collection of the dname in an inode audit message is not RCU + * safe. Note this may drop some audits when the situation changes + * during retry. However this is logically just as if the operation + * happened a little later. + */ + if ((a->type == LSM_AUDIT_DATA_FS) && + (flags & IPERM_FLAG_RCU)) + return -ECHILD; + a->selinux_audit_data.tclass = tclass; a->selinux_audit_data.requested = requested; a->selinux_audit_data.ssid = ssid; @@ -529,6 +544,7 @@ void avc_audit(u32 ssid, u32 tsid, a->lsm_pre_audit = avc_audit_pre_callback; a->lsm_post_audit = avc_audit_post_callback; common_lsm_audit(a); + return 0; } /** @@ -793,6 +809,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, * @tclass: target security class * @requested: requested permissions, interpreted based on @tclass * @auditdata: auxiliary audit data + * @flags: VFS walk flags * * Check the AVC to determine whether the @requested permissions are granted * for the SID pair (@ssid, @tsid), interpreting the permissions @@ -802,14 +819,19 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, * permissions are granted, -%EACCES if any permissions are denied, or * another -errno upon other errors. */ -int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, - u32 requested, struct common_audit_data *auditdata) +int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass, + u32 requested, struct common_audit_data *auditdata, + unsigned flags) { struct av_decision avd; - int rc; + int rc, rc2; rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd); - avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); + + rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata, + flags); + if (rc2) + return rc2; return rc; } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9a220be17a3f..ed5f29aa0a38 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1447,8 +1447,11 @@ static int task_has_capability(struct task_struct *tsk, } rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); - if (audit == SECURITY_CAP_AUDIT) - avc_audit(sid, sid, sclass, av, &avd, rc, &ad); + if (audit == SECURITY_CAP_AUDIT) { + int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); + if (rc2) + return rc2; + } return rc; } @@ -1468,7 +1471,8 @@ static int task_has_system(struct task_struct *tsk, static int inode_has_perm(const struct cred *cred, struct inode *inode, u32 perms, - struct common_audit_data *adp) + struct common_audit_data *adp, + unsigned flags) { struct inode_security_struct *isec; struct common_audit_data ad; @@ -1488,7 +1492,7 @@ static int inode_has_perm(const struct cred *cred, ad.u.fs.inode = inode; } - return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); + return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags); } /* Same as inode_has_perm, but pass explicit audit data containing @@ -1505,7 +1509,7 @@ static inline int dentry_has_perm(const struct cred *cred, COMMON_AUDIT_DATA_INIT(&ad, FS); ad.u.fs.path.mnt = mnt; ad.u.fs.path.dentry = dentry; - return inode_has_perm(cred, inode, av, &ad); + return inode_has_perm(cred, inode, av, &ad, 0); } /* Check whether a task can use an open file descriptor to @@ -1541,7 +1545,7 @@ static int file_has_perm(const struct cred *cred, /* av is zero if only checking access to the descriptor. */ rc = 0; if (av) - rc = inode_has_perm(cred, inode, av, &ad); + rc = inode_has_perm(cred, inode, av, &ad, 0); out: return rc; @@ -2103,7 +2107,7 @@ static inline void flush_unauthorized_files(const struct cred *cred, file = file_priv->file; inode = file->f_path.dentry->d_inode; if (inode_has_perm(cred, inode, - FILE__READ | FILE__WRITE, NULL)) { + FILE__READ | FILE__WRITE, NULL, 0)) { drop_tty = 1; } } @@ -2649,10 +2653,6 @@ static int selinux_inode_permission(struct inode *inode, int mask, unsigned flag if (!mask) return 0; - /* May be droppable after audit */ - if (flags & IPERM_FLAG_RCU) - return -ECHILD; - COMMON_AUDIT_DATA_INIT(&ad, FS); ad.u.fs.inode = inode; @@ -2661,7 +2661,7 @@ static int selinux_inode_permission(struct inode *inode, int mask, unsigned flag perms = file_mask_to_av(inode->i_mode, mask); - return inode_has_perm(cred, inode, perms, &ad); + return inode_has_perm(cred, inode, perms, &ad, flags); } static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) @@ -3208,7 +3208,7 @@ static int selinux_dentry_open(struct file *file, const struct cred *cred) * new inode label or new policy. * This check is not redundant - do not remove. */ - return inode_has_perm(cred, inode, open_file_to_av(file), NULL); + return inode_has_perm(cred, inode, open_file_to_av(file), NULL, 0); } /* task security operations */ diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h index 5615081b73ec..e77b2ac2908b 100644 --- a/security/selinux/include/avc.h +++ b/security/selinux/include/avc.h @@ -54,11 +54,11 @@ struct avc_cache_stats { void __init avc_init(void); -void avc_audit(u32 ssid, u32 tsid, +int avc_audit(u32 ssid, u32 tsid, u16 tclass, u32 requested, struct av_decision *avd, int result, - struct common_audit_data *a); + struct common_audit_data *a, unsigned flags); #define AVC_STRICT 1 /* Ignore permissive mode. */ int avc_has_perm_noaudit(u32 ssid, u32 tsid, @@ -66,9 +66,17 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, unsigned flags, struct av_decision *avd); -int avc_has_perm(u32 ssid, u32 tsid, - u16 tclass, u32 requested, - struct common_audit_data *auditdata); +int avc_has_perm_flags(u32 ssid, u32 tsid, + u16 tclass, u32 requested, + struct common_audit_data *auditdata, + unsigned); + +static inline int avc_has_perm(u32 ssid, u32 tsid, + u16 tclass, u32 requested, + struct common_audit_data *auditdata) +{ + return avc_has_perm_flags(ssid, tsid, tclass, requested, auditdata, 0); +} u32 avc_policy_seqno(void); |