Re: moving audit_free() up into do_exit()

On Fri, Mar 31, 2006 at 03:40:30PM -0500, Steve Grubb wrote: [snip] Fixed, pushed to kernel.org audit-current, updated patch follows: diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index 506462e..fd7eaf7 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -671,7 +671,7 @@ int do_syscall_trace(struct pt_regs *reg if (unlikely(current->audit_context)) { if (entryexit) - audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), + audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax); /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is @@ -720,14 +720,13 @@ int do_syscall_trace(struct pt_regs *reg ret = is_sysemu; out: if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(current, AUDIT_ARCH_I386, regs->orig_eax, + audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax, regs->ebx, regs->ecx, regs->edx, regs->esi); if (ret == 0) return 0; regs->orig_eax = -1; /* force skip of syscall restarting */ if (unlikely(current->audit_context)) - audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), - regs->eax); + audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax); return 1; } diff --git a/arch/i386/kernel/vm86.c b/arch/i386/kernel/vm86.c index aee14fa..00e0118 100644 --- a/arch/i386/kernel/vm86.c +++ b/arch/i386/kernel/vm86.c @@ -312,7 +312,7 @@ static void do_sys_vm86(struct kernel_vm /*call audit_syscall_exit since we do not exit via the normal paths */ if (unlikely(current->audit_context)) - audit_syscall_exit(current, AUDITSC_RESULT(eax), eax); + audit_syscall_exit(AUDITSC_RESULT(eax), eax); __asm__ __volatile__( "movl %0,%%esp\n\t" diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 9887c87..e61e15e 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1644,7 +1644,7 @@ syscall_trace_enter (long arg0, long arg arch = AUDIT_ARCH_IA64; } - audit_syscall_entry(current, arch, syscall, arg0, arg1, arg2, arg3); + audit_syscall_entry(arch, syscall, arg0, arg1, arg2, arg3); } } @@ -1662,7 +1662,7 @@ syscall_trace_leave (long arg0, long arg if (success != AUDITSC_SUCCESS) result = -result; - audit_syscall_exit(current, success, result); + audit_syscall_exit(success, result); } if (test_thread_flag(TIF_SYSCALL_TRACE) diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index f838b36..26ab8a9 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -469,7 +469,7 @@ static inline int audit_arch(void) asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) { if (unlikely(current->audit_context) && entryexit) - audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]), + audit_syscall_exit(AUDITSC_RESULT(regs->regs[2]), regs->regs[2]); if (!(current->ptrace & PT_PTRACED)) @@ -493,7 +493,7 @@ asmlinkage void do_syscall_trace(struct } out: if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(current, audit_arch(), regs->regs[2], + audit_syscall_entry(audit_arch(), regs->regs[2], regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]); } diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index bcb8357..4a677d1 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -538,7 +538,7 @@ void do_syscall_trace_enter(struct pt_re do_syscall_trace(); if (unlikely(current->audit_context)) - audit_syscall_entry(current, + audit_syscall_entry( #ifdef CONFIG_PPC32 AUDIT_ARCH_PPC, #else @@ -556,8 +556,7 @@ void do_syscall_trace_leave(struct pt_re #endif if (unlikely(current->audit_context)) - audit_syscall_exit(current, - (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS, + audit_syscall_exit((regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS, regs->result); if ((test_thread_flag(TIF_SYSCALL_TRACE) diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 37dfe33..8f36504 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -734,7 +734,7 @@ asmlinkage void syscall_trace(struct pt_regs *regs, int entryexit) { if (unlikely(current->audit_context) && entryexit) - audit_syscall_exit(current, AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]); + audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]); if (!test_thread_flag(TIF_SYSCALL_TRACE)) goto out; @@ -761,8 +761,7 @@ syscall_trace(struct pt_regs *regs, int } out: if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(current, - test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X, + audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X, regs->gprs[2], regs->orig_gpr2, regs->gprs[3], regs->gprs[4], regs->gprs[5]); } diff --git a/arch/sparc64/kernel/ptrace.c b/arch/sparc64/kernel/ptrace.c index eb93e9c..bd54daf 100644 --- a/arch/sparc64/kernel/ptrace.c +++ b/arch/sparc64/kernel/ptrace.c @@ -630,7 +630,7 @@ asmlinkage void syscall_trace(struct pt_ if (unlikely(tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) result = AUDITSC_FAILURE; - audit_syscall_exit(current, result, regs->u_regs[UREG_I0]); + audit_syscall_exit(result, regs->u_regs[UREG_I0]); } if (!(current->ptrace & PT_PTRACED)) @@ -654,8 +654,7 @@ asmlinkage void syscall_trace(struct pt_ out: if (unlikely(current->audit_context) && !syscall_exit_p) - audit_syscall_entry(current, - (test_thread_flag(TIF_32BIT) ? + audit_syscall_entry((test_thread_flag(TIF_32BIT) ? AUDIT_ARCH_SPARC : AUDIT_ARCH_SPARC64), regs->u_regs[UREG_G1], diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 98e0939..139c3ac 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -269,15 +269,13 @@ void syscall_trace(union uml_pt_regs *re if (unlikely(current->audit_context)) { if (!entryexit) - audit_syscall_entry(current, - HOST_AUDIT_ARCH, + audit_syscall_entry(HOST_AUDIT_ARCH, UPT_SYSCALL_NR(regs), UPT_SYSCALL_ARG1(regs), UPT_SYSCALL_ARG2(regs), UPT_SYSCALL_ARG3(regs), UPT_SYSCALL_ARG4(regs)); - else audit_syscall_exit(current, - AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), + else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), UPT_SYSCALL_RET(regs)); } diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c index d44b2c1..5ef7aae 100644 --- a/arch/x86_64/kernel/ptrace.c +++ b/arch/x86_64/kernel/ptrace.c @@ -605,12 +605,12 @@ asmlinkage void syscall_trace_enter(stru if (unlikely(current->audit_context)) { if (test_thread_flag(TIF_IA32)) { - audit_syscall_entry(current, AUDIT_ARCH_I386, + audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_rax, regs->rbx, regs->rcx, regs->rdx, regs->rsi); } else { - audit_syscall_entry(current, AUDIT_ARCH_X86_64, + audit_syscall_entry(AUDIT_ARCH_X86_64, regs->orig_rax, regs->rdi, regs->rsi, regs->rdx, regs->r10); @@ -621,7 +621,7 @@ asmlinkage void syscall_trace_enter(stru asmlinkage void syscall_trace_leave(struct pt_regs *regs) { if (unlikely(current->audit_context)) - audit_syscall_exit(current, AUDITSC_RESULT(regs->rax), regs->rax); + audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax); if ((test_thread_flag(TIF_SYSCALL_TRACE) || test_thread_flag(TIF_SINGLESTEP)) diff --git a/include/linux/audit.h b/include/linux/audit.h index 1c47c59..39fef6e 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -287,10 +287,10 @@ struct netlink_skb_parms; /* Public API */ extern int audit_alloc(struct task_struct *task); extern void audit_free(struct task_struct *task); -extern void audit_syscall_entry(struct task_struct *task, int arch, +extern void audit_syscall_entry(int arch, int major, unsigned long a0, unsigned long a1, unsigned long a2, unsigned long a3); -extern void audit_syscall_exit(struct task_struct *task, int failed, long return_code); +extern void audit_syscall_exit(int failed, long return_code); extern void audit_getname(const char *name); extern void audit_putname(const char *name); extern void __audit_inode(const char *name, const struct inode *inode, unsigned flags); @@ -323,8 +323,8 @@ extern int audit_set_macxattr(const char #else #define audit_alloc(t) ({ 0; }) #define audit_free(t) do { ; } while (0) -#define audit_syscall_entry(t,ta,a,b,c,d,e) do { ; } while (0) -#define audit_syscall_exit(t,f,r) do { ; } while (0) +#define audit_syscall_entry(ta,a,b,c,d,e) do { ; } while (0) +#define audit_syscall_exit(f,r) do { ; } while (0) #define audit_getname(n) do { ; } while (0) #define audit_putname(n) do { ; } while (0) #define __audit_inode(n,i,f) do { ; } while (0) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 4052f0a..8aca4ab 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -329,7 +329,6 @@ static enum audit_state audit_filter_sys return AUDIT_BUILD_CONTEXT; } -/* This should be called with task_lock() held. */ static inline struct audit_context *audit_get_context(struct task_struct *tsk, int return_valid, int return_code) @@ -506,7 +505,7 @@ static inline void audit_free_context(st printk(KERN_ERR "audit: freed %d contexts\n", count); } -static void audit_log_task_context(struct audit_buffer *ab, gfp_t gfp_mask) +static void audit_log_task_context(struct audit_buffer *ab) { char *ctx = NULL; ssize_t len = 0; @@ -518,7 +517,7 @@ static void audit_log_task_context(struc return; } - ctx = kmalloc(len, gfp_mask); + ctx = kmalloc(len, GFP_KERNEL); if (!ctx) goto error_path; @@ -536,47 +535,46 @@ error_path: return; } -static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk, gfp_t gfp_mask) +static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) { char name[sizeof(tsk->comm)]; struct mm_struct *mm = tsk->mm; struct vm_area_struct *vma; + /* tsk == current */ + get_task_comm(name, tsk); audit_log_format(ab, " comm="); audit_log_untrustedstring(ab, name); - if (!mm) - return; - - /* - * this is brittle; all callers that pass GFP_ATOMIC will have - * NULL tsk->mm and we won't get here. - */ - down_read(&mm->mmap_sem); - vma = mm->mmap; - while (vma) { - if ((vma->vm_flags & VM_EXECUTABLE) && - vma->vm_file) { - audit_log_d_path(ab, "exe=", - vma->vm_file->f_dentry, - vma->vm_file->f_vfsmnt); - break; + if (mm) { + down_read(&mm->mmap_sem); + vma = mm->mmap; + while (vma) { + if ((vma->vm_flags & VM_EXECUTABLE) && + vma->vm_file) { + audit_log_d_path(ab, "exe=", + vma->vm_file->f_dentry, + vma->vm_file->f_vfsmnt); + break; + } + vma = vma->vm_next; } - vma = vma->vm_next; + up_read(&mm->mmap_sem); } - up_read(&mm->mmap_sem); - audit_log_task_context(ab, gfp_mask); + audit_log_task_context(ab); } -static void audit_log_exit(struct audit_context *context, struct task_struct *tsk, gfp_t gfp_mask) +static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { int i; struct audit_buffer *ab; struct audit_aux_data *aux; const char *tty; - ab = audit_log_start(context, gfp_mask, AUDIT_SYSCALL); + /* tsk == current */ + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL); if (!ab) return; /* audit_panic has been called */ audit_log_format(ab, "arch=%x syscall=%d", @@ -607,12 +605,12 @@ static void audit_log_exit(struct audit_ context->gid, context->euid, context->suid, context->fsuid, context->egid, context->sgid, context->fsgid, tty); - audit_log_task_info(ab, gfp_mask); + audit_log_task_info(ab, tsk); audit_log_end(ab); for (aux = context->aux; aux; aux = aux->next) { - ab = audit_log_start(context, gfp_mask, aux->type); + ab = audit_log_start(context, GFP_KERNEL, aux->type); if (!ab) continue; /* audit_panic has been called */ @@ -649,7 +647,7 @@ static void audit_log_exit(struct audit_ } if (context->pwd && context->pwdmnt) { - ab = audit_log_start(context, gfp_mask, AUDIT_CWD); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); if (ab) { audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt); audit_log_end(ab); @@ -659,7 +657,7 @@ static void audit_log_exit(struct audit_ unsigned long ino = context->names[i].ino; unsigned long pino = context->names[i].pino; - ab = audit_log_start(context, gfp_mask, AUDIT_PATH); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); if (!ab) continue; /* audit_panic has been called */ @@ -698,19 +696,12 @@ static void audit_log_exit(struct audit_ * audit_free - free a per-task audit context * @tsk: task whose audit context block to free * - * Called from copy_process and __put_task_struct. + * Called from copy_process and do_exit */ void audit_free(struct task_struct *tsk) { struct audit_context *context; - /* - * No need to lock the task - when we execute audit_free() - * then the task has no external references anymore, and - * we are tearing it down. (The locking also confuses - * DEBUG_LOCKDEP - this freeing may occur in softirq - * contexts as well, via RCU.) - */ context = audit_get_context(tsk, 0, 0); if (likely(!context)) return; @@ -719,8 +710,9 @@ void audit_free(struct task_struct *tsk) * function (e.g., exit_group), then free context block. * We use GFP_ATOMIC here because we might be doing this * in the context of the idle thread */ + /* that can happen only if we are called from do_exit() */ if (context->in_syscall && context->auditable) - audit_log_exit(context, tsk, GFP_ATOMIC); + audit_log_exit(context, tsk); audit_free_context(context); } @@ -743,10 +735,11 @@ void audit_free(struct task_struct *tsk) * will only be written if another part of the kernel requests that it * be written). */ -void audit_syscall_entry(struct task_struct *tsk, int arch, int major, +void audit_syscall_entry(int arch, int major, unsigned long a1, unsigned long a2, unsigned long a3, unsigned long a4) { + struct task_struct *tsk = current; struct audit_context *context = tsk->audit_context; enum audit_state state; @@ -824,22 +817,18 @@ void audit_syscall_entry(struct task_str * message), then write out the syscall information. In call cases, * free the names stored from getname(). */ -void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) +void audit_syscall_exit(int valid, long return_code) { + struct task_struct *tsk = current; struct audit_context *context; - get_task_struct(tsk); - task_lock(tsk); context = audit_get_context(tsk, valid, return_code); - task_unlock(tsk); - /* Not having a context here is ok, since the parent may have - * called __put_task_struct. */ if (likely(!context)) - goto out; + return; if (context->in_syscall && context->auditable) - audit_log_exit(context, tsk, GFP_KERNEL); + audit_log_exit(context, tsk); context->in_syscall = 0; context->auditable = 0; @@ -854,8 +843,6 @@ void audit_syscall_exit(struct task_stru audit_free_aux(context); tsk->audit_context = context; } - out: - put_task_struct(tsk); } /** diff --git a/kernel/exit.c b/kernel/exit.c index bc0ec67..70bd67b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -34,6 +34,7 @@ #include <linux/mutex.h> #include <linux/futex.h> #include <linux/compat.h> +#include <linux/audit.h> /* for audit_free() */ #include <asm/uaccess.h> #include <asm/unistd.h> @@ -904,6 +905,8 @@ fastcall NORET_TYPE void do_exit(long co if (unlikely(tsk->compat_robust_list)) compat_exit_robust_list(tsk); #endif + if (unlikely(tsk->audit_context)) + audit_free(tsk); exit_mm(tsk); exit_sem(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index b3f7a1b..be4a935 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -116,8 +116,6 @@ void __put_task_struct_cb(struct rcu_hea WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); - if (unlikely(tsk->audit_context)) - audit_free(tsk); security_task_free(tsk); free_uid(tsk->user); put_group_info(tsk->group_info);