From 2fd6f58ba6efc82ea2c9c2630f7ff5ed9eeaf34a Mon Sep 17 00:00:00 2001 From: Date: Fri, 29 Apr 2005 16:08:28 +0100 Subject: [PATCH] [AUDIT] Don't allow ptrace to fool auditing, log arch of audited syscalls. We were calling ptrace_notify() after auditing the syscall and arguments, but the debugger could have _changed_ them before the syscall was actually invoked. Reorder the calls to fix that. While we're touching ever call to audit_syscall_entry(), we also make it take an extra argument: the architecture of the syscall which was made, because some architectures allow more than one type of syscall. Also add an explicit success/failure flag to audit_syscall_exit(), for the benefit of architectures which return that in a condition register rather than only returning a single register. Change type of syscall return value to 'long' not 'int'. Signed-off-by: David Woodhouse --- arch/i386/kernel/ptrace.c | 19 +++++++-------- arch/ia64/kernel/ptrace.c | 21 +++++++++------- arch/mips/kernel/ptrace.c | 38 +++++++++++++++++++++-------- arch/ppc64/kernel/ptrace.c | 15 ++++++++---- arch/s390/kernel/ptrace.c | 21 ++++++++-------- arch/x86_64/kernel/ptrace.c | 13 ++++++---- include/linux/audit.h | 48 +++++++++++++++++++++++++++++++++---- kernel/auditsc.c | 22 ++++++++++++----- 8 files changed, 139 insertions(+), 58 deletions(-) diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index b2f17640ce..5606ec7a5c 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -682,24 +682,18 @@ void do_syscall_trace(struct pt_regs *regs, int entryexit) /* do the secure computing check first */ secure_computing(regs->orig_eax); - if (unlikely(current->audit_context)) { - if (!entryexit) - audit_syscall_entry(current, regs->orig_eax, - regs->ebx, regs->ecx, - regs->edx, regs->esi); - else - audit_syscall_exit(current, regs->eax); - } + if (unlikely(current->audit_context) && entryexit) + audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax); if (!(current->ptrace & PT_PTRACED)) - return; + goto out; /* Fake a debug trap */ if (test_thread_flag(TIF_SINGLESTEP)) send_sigtrap(current, regs, 0); if (!test_thread_flag(TIF_SYSCALL_TRACE)) - return; + goto out; /* the 0x80 provides a way for the tracing parent to distinguish between a syscall stop and SIGTRAP delivery */ @@ -714,4 +708,9 @@ void do_syscall_trace(struct pt_regs *regs, int entryexit) send_sig(current->exit_code, current, 1); current->exit_code = 0; } + out: + if (unlikely(current->audit_context) && !entryexit) + audit_syscall_entry(current, AUDIT_ARCH_I386, regs->orig_eax, + regs->ebx, regs->ecx, regs->edx, regs->esi); + } diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 55789fcd72..8dde0b16d4 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1595,20 +1595,25 @@ syscall_trace_enter (long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long arg6, long arg7, struct pt_regs regs) { - long syscall; + if (test_thread_flag(TIF_SYSCALL_TRACE) + && (current->ptrace & PT_PTRACED)) + syscall_trace(); if (unlikely(current->audit_context)) { - if (IS_IA32_PROCESS(®s)) + long syscall; + int arch; + + if (IS_IA32_PROCESS(®s)) { syscall = regs.r1; - else + arch = AUDIT_ARCH_I386; + } else { syscall = regs.r15; + arch = AUDIT_ARCH_IA64; + } - audit_syscall_entry(current, syscall, arg0, arg1, arg2, arg3); + audit_syscall_entry(current, arch, syscall, arg0, arg1, arg2, arg3); } - if (test_thread_flag(TIF_SYSCALL_TRACE) - && (current->ptrace & PT_PTRACED)) - syscall_trace(); } /* "asmlinkage" so the input arguments are preserved... */ @@ -1619,7 +1624,7 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3, struct pt_regs regs) { if (unlikely(current->audit_context)) - audit_syscall_exit(current, regs.r8); + audit_syscall_exit(current, AUDITSC_RESULT(regs.r10), regs.r8); if (test_thread_flag(TIF_SYSCALL_TRACE) && (current->ptrace & PT_PTRACED)) diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index 92f2c39afe..eaf7be9d0b 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -300,25 +300,38 @@ out: return ret; } +static inline int audit_arch() +{ +#ifdef CONFIG_CPU_LITTLE_ENDIAN +#ifdef CONFIG_MIPS64 + if (!(current->thread.mflags & MF_32BIT_REGS)) + return AUDIT_ARCH_MIPSEL64; +#endif /* MIPS64 */ + return AUDIT_ARCH_MIPSEL; + +#else /* big endian... */ +#ifdef CONFIG_MIPS64 + if (!(current->thread.mflags & MF_32BIT_REGS)) + return AUDIT_ARCH_MIPS64; +#endif /* MIPS64 */ + return AUDIT_ARCH_MIPS; + +#endif /* endian */ +} + /* * Notification of system call entry/exit * - triggered by current->work.syscall_trace */ asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) { - if (unlikely(current->audit_context)) { - if (!entryexit) - audit_syscall_entry(current, regs->regs[2], - regs->regs[4], regs->regs[5], - regs->regs[6], regs->regs[7]); - else - audit_syscall_exit(current, regs->regs[2]); - } + if (unlikely(current->audit_context) && entryexit) + audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]), regs->regs[2]); if (!test_thread_flag(TIF_SYSCALL_TRACE)) - return; + goto out; if (!(current->ptrace & PT_PTRACED)) - return; + goto out; /* The 0x80 provides a way for the tracing parent to distinguish between a syscall stop and SIGTRAP delivery */ @@ -334,4 +347,9 @@ asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) send_sig(current->exit_code, current, 1); current->exit_code = 0; } + out: + if (unlikely(current->audit_context) && !entryexit) + audit_syscall_entry(current, audit_arch(), regs->regs[2], + regs->regs[4], regs->regs[5], + regs->regs[6], regs->regs[7]); } diff --git a/arch/ppc64/kernel/ptrace.c b/arch/ppc64/kernel/ptrace.c index 354a287c67..3c76333ec3 100644 --- a/arch/ppc64/kernel/ptrace.c +++ b/arch/ppc64/kernel/ptrace.c @@ -304,14 +304,17 @@ static void do_syscall_trace(void) void do_syscall_trace_enter(struct pt_regs *regs) { + if (test_thread_flag(TIF_SYSCALL_TRACE) + && (current->ptrace & PT_PTRACED)) + do_syscall_trace(); + if (unlikely(current->audit_context)) - audit_syscall_entry(current, regs->gpr[0], + audit_syscall_entry(current, + test_thread_flag(TIF_32BIT)?AUDIT_ARCH_PPC:AUDIT_ARCH_PPC64, + regs->gpr[0], regs->gpr[3], regs->gpr[4], regs->gpr[5], regs->gpr[6]); - if (test_thread_flag(TIF_SYSCALL_TRACE) - && (current->ptrace & PT_PTRACED)) - do_syscall_trace(); } void do_syscall_trace_leave(struct pt_regs *regs) @@ -319,7 +322,9 @@ void do_syscall_trace_leave(struct pt_regs *regs) secure_computing(regs->gpr[0]); if (unlikely(current->audit_context)) - audit_syscall_exit(current, regs->result); + audit_syscall_exit(current, + (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS, + regs->result); if ((test_thread_flag(TIF_SYSCALL_TRACE) || test_thread_flag(TIF_SINGLESTEP)) diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 647233c02f..2d546c67f7 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -711,18 +711,13 @@ out: asmlinkage void syscall_trace(struct pt_regs *regs, int entryexit) { - if (unlikely(current->audit_context)) { - if (!entryexit) - audit_syscall_entry(current, regs->gprs[2], - regs->orig_gpr2, regs->gprs[3], - regs->gprs[4], regs->gprs[5]); - else - audit_syscall_exit(current, regs->gprs[2]); - } + if (unlikely(current->audit_context) && entryexit) + audit_syscall_exit(current, AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]); + if (!test_thread_flag(TIF_SYSCALL_TRACE)) - return; + goto out; if (!(current->ptrace & PT_PTRACED)) - return; + goto out; ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); @@ -735,4 +730,10 @@ syscall_trace(struct pt_regs *regs, int entryexit) send_sig(current->exit_code, current, 1); current->exit_code = 0; } + out: + if (unlikely(current->audit_context) && !entryexit) + audit_syscall_entry(current, + 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/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c index c701167500..ecbccbbf5c 100644 --- a/arch/x86_64/kernel/ptrace.c +++ b/arch/x86_64/kernel/ptrace.c @@ -629,25 +629,28 @@ static void syscall_trace(struct pt_regs *regs) } } +#define audit_arch() (test_thread_flag(TIF_IA32) ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64) + asmlinkage void syscall_trace_enter(struct pt_regs *regs) { /* do the secure computing check first */ secure_computing(regs->orig_rax); + if (test_thread_flag(TIF_SYSCALL_TRACE) + && (current->ptrace & PT_PTRACED)) + syscall_trace(regs); + if (unlikely(current->audit_context)) - audit_syscall_entry(current, regs->orig_rax, + audit_syscall_entry(current, audit_arch(), regs->orig_rax, regs->rdi, regs->rsi, regs->rdx, regs->r10); - if (test_thread_flag(TIF_SYSCALL_TRACE) - && (current->ptrace & PT_PTRACED)) - syscall_trace(regs); } asmlinkage void syscall_trace_leave(struct pt_regs *regs) { if (unlikely(current->audit_context)) - audit_syscall_exit(current, regs->rax); + audit_syscall_exit(current, 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 9b77992c48..fad0c1dc21 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -24,6 +24,9 @@ #ifndef _LINUX_AUDIT_H_ #define _LINUX_AUDIT_H_ +#include +#include + /* Request and reply types */ #define AUDIT_GET 1000 /* Get status */ #define AUDIT_SET 1001 /* Set status (enable/disable/auditd) */ @@ -67,6 +70,7 @@ #define AUDIT_FSGID 8 #define AUDIT_LOGINUID 9 #define AUDIT_PERS 10 +#define AUDIT_ARCH 11 /* These are ONLY useful when checking * at syscall exit time (AUDIT_AT_EXIT). */ @@ -96,6 +100,38 @@ #define AUDIT_FAIL_PRINTK 1 #define AUDIT_FAIL_PANIC 2 +/* distinguish syscall tables */ +#define __AUDIT_ARCH_64BIT 0x80000000 +#define __AUDIT_ARCH_LE 0x40000000 +#define AUDIT_ARCH_ALPHA (EM_ALPHA|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_ARM (EM_ARM|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_ARMEB (EM_ARM) +#define AUDIT_ARCH_CRIS (EM_CRIS|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_FRV (EM_FRV) +#define AUDIT_ARCH_H8300 (EM_H8_300) +#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_IA64 (EM_IA_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_M32R (EM_M32R) +#define AUDIT_ARCH_M68K (EM_68K) +#define AUDIT_ARCH_MIPS (EM_MIPS) +#define AUDIT_ARCH_MIPSEL (EM_MIPS|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_MIPS64 (EM_MIPS|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_MIPSEL64 (EM_MIPS|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_PARISC (EM_PARISC) +#define AUDIT_ARCH_PARISC64 (EM_PARISC|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_PPC (EM_PPC) +#define AUDIT_ARCH_PPC64 (EM_PPC64|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_S390 (EM_S390) +#define AUDIT_ARCH_S390X (EM_S390|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_SH (EM_SH) +#define AUDIT_ARCH_SHEL (EM_SH|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_SH64 (EM_SH|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_SHEL64 (EM_SH|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_SPARC (EM_SPARC) +#define AUDIT_ARCH_SPARC64 (EM_SPARC64|__AUDIT_ARCH_64BIT) +#define AUDIT_ARCH_V850 (EM_V850|__AUDIT_ARCH_LE) +#define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) + #ifndef __KERNEL__ struct audit_message { struct nlmsghdr nlh; @@ -129,15 +165,19 @@ struct audit_buffer; struct audit_context; struct inode; +#define AUDITSC_INVALID 0 +#define AUDITSC_SUCCESS 1 +#define AUDITSC_FAILURE 2 +#define AUDITSC_RESULT(x) ( ((long)(x))<0?AUDITSC_FAILURE:AUDITSC_SUCCESS ) #ifdef CONFIG_AUDITSYSCALL /* These are defined in auditsc.c */ /* 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, +extern void audit_syscall_entry(struct task_struct *task, 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 return_code); +extern void audit_syscall_exit(struct task_struct *task, 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); @@ -153,8 +193,8 @@ extern int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mo #else #define audit_alloc(t) ({ 0; }) #define audit_free(t) do { ; } while (0) -#define audit_syscall_entry(t,a,b,c,d,e) do { ; } while (0) -#define audit_syscall_exit(t,r) 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_getname(n) do { ; } while (0) #define audit_putname(n) do { ; } while (0) #define audit_inode(n,i) do { ; } while (0) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 00e87ffff1..77e92592de 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -123,7 +123,7 @@ struct audit_context { int major; /* syscall number */ unsigned long argv[4]; /* syscall arguments */ int return_valid; /* return code is valid */ - int return_code;/* syscall return code */ + long return_code;/* syscall return code */ int auditable; /* 1 if record should be written */ int name_count; struct audit_names names[AUDIT_NAMES]; @@ -135,6 +135,7 @@ struct audit_context { uid_t uid, euid, suid, fsuid; gid_t gid, egid, sgid, fsgid; unsigned long personality; + int arch; #if AUDIT_DEBUG int put_count; @@ -348,6 +349,10 @@ static int audit_filter_rules(struct task_struct *tsk, case AUDIT_PERS: result = (tsk->personality == value); break; + case AUDIT_ARCH: + if (ctx) + result = (ctx->arch == value); + break; case AUDIT_EXIT: if (ctx && ctx->return_valid) @@ -355,7 +360,7 @@ static int audit_filter_rules(struct task_struct *tsk, break; case AUDIT_SUCCESS: if (ctx && ctx->return_valid) - result = (ctx->return_code >= 0); + result = (ctx->return_valid == AUDITSC_SUCCESS); break; case AUDIT_DEVMAJOR: if (ctx) { @@ -648,8 +653,11 @@ static void audit_log_exit(struct audit_context *context) audit_log_format(ab, "syscall=%d", context->major); if (context->personality != PER_LINUX) audit_log_format(ab, " per=%lx", context->personality); + audit_log_format(ab, " arch=%x", context->arch); if (context->return_valid) - audit_log_format(ab, " exit=%d", context->return_code); + audit_log_format(ab, " success=%s exit=%ld", + (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", + context->return_code); audit_log_format(ab, " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" " pid=%d loginuid=%d uid=%d gid=%d" @@ -773,7 +781,7 @@ static inline unsigned int audit_serial(void) * then the record will be written at syscall exit time (otherwise, it * will only be written if another part of the kernel requests that it * be written). */ -void audit_syscall_entry(struct task_struct *tsk, int major, +void audit_syscall_entry(struct task_struct *tsk, int arch, int major, unsigned long a1, unsigned long a2, unsigned long a3, unsigned long a4) { @@ -827,6 +835,7 @@ void audit_syscall_entry(struct task_struct *tsk, int major, if (!audit_enabled) return; + context->arch = arch; context->major = major; context->argv[0] = a1; context->argv[1] = a2; @@ -850,13 +859,13 @@ void audit_syscall_entry(struct task_struct *tsk, int major, * filtering, or because some other part of the kernel write an audit * 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 return_code) +void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) { struct audit_context *context; get_task_struct(tsk); task_lock(tsk); - context = audit_get_context(tsk, 1, return_code); + context = audit_get_context(tsk, valid, return_code); task_unlock(tsk); /* Not having a context here is ok, since the parent may have @@ -869,6 +878,7 @@ void audit_syscall_exit(struct task_struct *tsk, int return_code) context->in_syscall = 0; context->auditable = 0; + if (context->previous) { struct audit_context *new_context = context->previous; context->previous = NULL; -- 2.39.5