From 011161051bbc25f7f8b7df059dbd934c534443f0 Mon Sep 17 00:00:00 2001 From: Stephen Smalley Date: Sat, 21 May 2005 00:15:52 +0100 Subject: [PATCH] AUDIT: Avoid sleeping function in SElinux AVC audit. This patch changes the SELinux AVC to defer logging of paths to the audit framework upon syscall exit, by saving a reference to the (dentry,vfsmount) pair in an auxiliary audit item on the current audit context for processing by audit_log_exit. Signed-off-by: Stephen Smalley Signed-off-by: David Woodhouse --- include/linux/audit.h | 3 +++ kernel/auditsc.c | 40 ++++++++++++++++++++++++++++++++++++++++ security/selinux/avc.c | 17 ++++++++--------- 3 files changed, 51 insertions(+), 9 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 17ea5d522d8..4b7caf0c6e1 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -69,6 +69,7 @@ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ +#define AUDIT_AVC_PATH 1402 /* dentry, vfsmount pair from avc */ #define AUDIT_KERNEL 2000 /* Asynchronous audit record. NOT A REQUEST. */ @@ -225,6 +226,7 @@ extern uid_t audit_get_loginuid(struct audit_context *ctx); extern int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode); extern int audit_socketcall(int nargs, unsigned long *args); extern int audit_sockaddr(int len, void *addr); +extern int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt); extern void audit_signal_info(int sig, struct task_struct *t); #else #define audit_alloc(t) ({ 0; }) @@ -240,6 +242,7 @@ extern void audit_signal_info(int sig, struct task_struct *t); #define audit_ipc_perms(q,u,g,m) ({ 0; }) #define audit_socketcall(n,a) ({ 0; }) #define audit_sockaddr(len, addr) ({ 0; }) +#define audit_avc_path(dentry, mnt) ({ 0; }) #define audit_signal_info(s,t) do { ; } while (0) #endif diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 78d7a13fc86..8dc5b276714 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include #include @@ -124,6 +125,11 @@ struct audit_aux_data_sockaddr { char a[0]; }; +struct audit_aux_data_path { + struct audit_aux_data d; + struct dentry *dentry; + struct vfsmount *mnt; +}; /* The per-task audit context. */ struct audit_context { @@ -553,6 +559,11 @@ static inline void audit_free_aux(struct audit_context *context) struct audit_aux_data *aux; while ((aux = context->aux)) { + if (aux->type == AUDIT_AVC_PATH) { + struct audit_aux_data_path *axi = (void *)aux; + dput(axi->dentry); + mntput(axi->mnt); + } context->aux = aux->next; kfree(aux); } @@ -724,6 +735,14 @@ static void audit_log_exit(struct audit_context *context) audit_log_format(ab, "saddr="); audit_log_hex(ab, axs->a, axs->len); break; } + + case AUDIT_AVC_PATH: { + struct audit_aux_data_path *axi = (void *)aux; + audit_log_d_path(ab, "path=", axi->dentry, axi->mnt); + dput(axi->dentry); + mntput(axi->mnt); + break; } + } audit_log_end(ab); @@ -1124,6 +1143,27 @@ int audit_sockaddr(int len, void *a) return 0; } +int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt) +{ + struct audit_aux_data_path *ax; + struct audit_context *context = current->audit_context; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + ax->dentry = dget(dentry); + ax->mnt = mntget(mnt); + + ax->d.type = AUDIT_AVC_PATH; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + void audit_signal_info(int sig, struct task_struct *t) { extern pid_t audit_sig_pid; diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 62b963aca27..0fbc3e98c5e 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -573,13 +573,10 @@ void avc_audit(u32 ssid, u32 tsid, case AVC_AUDIT_DATA_FS: if (a->u.fs.dentry) { struct dentry *dentry = a->u.fs.dentry; - if (a->u.fs.mnt) { - audit_log_d_path(ab, "path=", dentry, - a->u.fs.mnt); - } else { - audit_log_format(ab, " name=%s", - dentry->d_name.name); - } + if (a->u.fs.mnt) + audit_avc_path(dentry, a->u.fs.mnt); + audit_log_format(ab, " name=%s", + dentry->d_name.name); inode = dentry->d_inode; } else if (a->u.fs.inode) { struct dentry *dentry; @@ -630,8 +627,10 @@ void avc_audit(u32 ssid, u32 tsid, case AF_UNIX: u = unix_sk(sk); if (u->dentry) { - audit_log_d_path(ab, "path=", - u->dentry, u->mnt); + audit_avc_path(u->dentry, u->mnt); + audit_log_format(ab, " name=%s", + u->dentry->d_name.name); + break; } if (!u->addr)