[PATCH] seccomp: remove duplicated failure logging

From: Kees Cook
Date: Mon Feb 27 2012 - 14:25:31 EST


This consolidates the seccomp filter error logging path and adds more
details to the audit log.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

---
To be applied on top of Will Drewry's seccomp series, specifically
"[PATCH v11 06/12] seccomp: add system call filtering using BPF".

v2:
- drop compat (really arch) for now.
---
include/linux/audit.h | 8 ++++----
kernel/auditsc.c | 5 +++--
kernel/seccomp.c | 15 +--------------
3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 9ff7a2c..5aac29b 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -463,7 +463,7 @@ extern void audit_putname(const char *name);
extern void __audit_inode(const char *name, const struct dentry *dentry);
extern void __audit_inode_child(const struct dentry *dentry,
const struct inode *parent);
-extern void __audit_seccomp(unsigned long syscall);
+extern void __audit_seccomp(unsigned long syscall, long signr);
extern void __audit_ptrace(struct task_struct *t);

static inline int audit_dummy_context(void)
@@ -508,10 +508,10 @@ static inline void audit_inode_child(const struct dentry *dentry,
}
void audit_core_dumps(long signr);

-static inline void audit_seccomp(unsigned long syscall)
+static inline void audit_seccomp(unsigned long syscall, long signr)
{
if (unlikely(!audit_dummy_context()))
- __audit_seccomp(syscall);
+ __audit_seccomp(syscall, signr);
}

static inline void audit_ptrace(struct task_struct *t)
@@ -634,7 +634,7 @@ extern int audit_signals;
#define audit_inode(n,d) do { (void)(d); } while (0)
#define audit_inode_child(i,p) do { ; } while (0)
#define audit_core_dumps(i) do { ; } while (0)
-#define audit_seccomp(i) do { ; } while (0)
+#define audit_seccomp(i, s) do { ; } while (0)
#define auditsc_get_stamp(c,t,s) (0)
#define audit_get_loginuid(t) (-1)
#define audit_get_sessionid(t) (-1)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index af1de0f..2150339 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2710,13 +2710,14 @@ void audit_core_dumps(long signr)
audit_log_end(ab);
}

-void __audit_seccomp(unsigned long syscall)
+void __audit_seccomp(unsigned long syscall, long signr)
{
struct audit_buffer *ab;

ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
- audit_log_abend(ab, "seccomp", SIGKILL);
+ audit_log_abend(ab, "seccomp", signr);
audit_log_format(ab, " syscall=%ld", syscall);
+ audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
audit_log_end(ab);
}

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 5aabc3c..40af83f 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -57,18 +57,6 @@ struct seccomp_filter {
struct sock_filter insns[];
};

-static void seccomp_filter_log_failure(int syscall)
-{
- int compat = 0;
-#ifdef CONFIG_COMPAT
- compat = is_compat_task();
-#endif
- pr_info("%s[%d]: %ssystem call %d blocked at 0x%lx\n",
- current->comm, task_pid_nr(current),
- (compat ? "compat " : ""),
- syscall, KSTK_EIP(current));
-}
-
/**
* get_u32 - returns a u32 offset into data
* @data: a unsigned 64 bit value
@@ -378,7 +366,6 @@ int __secure_computing_int(int this_syscall)
default:
break;
}
- seccomp_filter_log_failure(this_syscall);
exit_code = SIGSYS;
break;
}
@@ -390,7 +377,7 @@ int __secure_computing_int(int this_syscall)
#ifdef SECCOMP_DEBUG
dump_stack();
#endif
- audit_seccomp(this_syscall);
+ audit_seccomp(this_syscall, exit_code);
do_exit(exit_code);
return -1; /* never reached */
}
--
1.7.0.4

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