[PATCH 3/4][v2] audit: move audit_aux_data_execve contents into audit_context union

audit_bprm() was being called to add an AUDIT_EXECVE record to the audit context every time search_binary_handler() was recursively called. Only one reference is necessary, so just update it. Move the the contents of audit_aux_data_execve into the union in audit_context, removing dependence on a kmalloc along the way. Reported-by: Oleg Nesterov <onestero(a)redhat.com&gt; Cc: Eric Paris <eparis(a)redhat.com&gt; Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- include/linux/audit.h | 4 ++-- kernel/audit.h | 4 ++++ kernel/auditsc.c | 41 ++++++++++++----------------------------- 3 files changed, 18 insertions(+), 31 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 729a4d1..fffefbd 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -207,7 +207,7 @@ static inline int audit_get_sessionid(struct task_struct *tsk) extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp); extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode); -extern int __audit_bprm(struct linux_binprm *bprm); +extern void __audit_bprm(struct linux_binprm *bprm); extern int __audit_socketcall(int nargs, unsigned long *args); extern int __audit_sockaddr(int len, void *addr); extern void __audit_fd_pair(int fd1, int fd2); @@ -239,7 +239,7 @@ static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid static inline int audit_bprm(struct linux_binprm *bprm) { if (unlikely(!audit_dummy_context())) - return __audit_bprm(bprm); + __audit_bprm(bprm); return 0; } static inline int audit_socketcall(int nargs, unsigned long *args) diff --git a/kernel/audit.h b/kernel/audit.h index 123c9b7..e7b94ab 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -197,6 +197,10 @@ struct audit_context { int fd; int flags; } mmap; + struct { + int argc; + struct mm_struct *mm; + } execve; }; int fds[2]; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index c9abaa0..eabe76a 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -95,12 +95,6 @@ struct audit_aux_data { /* Number of target pids per aux struct. */ #define AUDIT_AUX_PIDS 16 -struct audit_aux_data_execve { - struct audit_aux_data d; - int argc; - struct mm_struct *mm; -}; - struct audit_aux_data_pids { struct audit_aux_data d; pid_t target_pid[AUDIT_AUX_PIDS]; @@ -1144,20 +1138,19 @@ static int audit_log_single_execve_arg(struct audit_context *context, } static void audit_log_execve_info(struct audit_context *context, - struct audit_buffer **ab, - struct audit_aux_data_execve *axi) + struct audit_buffer **ab) { int i, len; size_t len_sent = 0; const char __user *p; char *buf; - if (axi->mm != current->mm) + if (context->execve.mm != current->mm) return; /* execve failed, no additional info */ - p = (const char __user *)axi->mm->arg_start; + p = (const char __user *)current->mm->arg_start; - audit_log_format(*ab, "argc=%d", axi->argc); + audit_log_format(*ab, "argc=%d", context->execve.argc); /* * we need some kernel buffer to hold the userspace args. Just @@ -1171,7 +1164,7 @@ static void audit_log_execve_info(struct audit_context *context, return; } - for (i = 0; i < axi->argc; i++) { + for (i = 0; i < context->execve.argc; i++) { len = audit_log_single_execve_arg(context, ab, i, &len_sent, p, buf); if (len <= 0) @@ -1274,6 +1267,9 @@ static void show_special(struct audit_context *context, int *call_panic) audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd, context->mmap.flags); break; } + case AUDIT_EXECVE: { + audit_log_execve_info(context, &ab); + break; } } audit_log_end(ab); } @@ -1320,11 +1316,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts switch (aux->type) { - case AUDIT_EXECVE: { - struct audit_aux_data_execve *axi = (void *)aux; - audit_log_execve_info(context, &ab, axi); - break; } - case AUDIT_BPRM_FCAPS: { struct audit_aux_data_bprm_fcaps *axs = (void *)aux; audit_log_format(ab, "fver=%x", axs->fcap_ver); @@ -2121,21 +2112,13 @@ void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mo context->ipc.has_perm = 1; } -int __audit_bprm(struct linux_binprm *bprm) +void __audit_bprm(struct linux_binprm *bprm) { - struct audit_aux_data_execve *ax; struct audit_context *context = current->audit_context; - ax = kmalloc(sizeof(*ax), GFP_KERNEL); - if (!ax) - return -ENOMEM; - - ax->argc = bprm->argc; - ax->mm = bprm->mm; - ax->d.type = AUDIT_EXECVE; - ax->d.next = context->aux; - context->aux = (void *)ax; - return 0; + context->type = AUDIT_EXECVE; + context->execve.argc = bprm->argc; + context->execve.mm = bprm->mm; } -- 1.7.1