diff options
Diffstat (limited to 'kernel/printk.c')
| -rw-r--r-- | kernel/printk.c | 45 |
1 files changed, 34 insertions, 11 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index b2ebaee8c377..f64b8997fc76 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -43,12 +43,6 @@ #include <asm/uaccess.h> /* - * for_each_console() allows you to iterate on each console - */ -#define for_each_console(con) \ - for (con = console_drivers; con != NULL; con = con->next) - -/* * Architectures can override it: */ void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...) @@ -261,6 +255,12 @@ static inline void boot_delay_msec(void) } #endif +#ifdef CONFIG_SECURITY_DMESG_RESTRICT +int dmesg_restrict = 1; +#else +int dmesg_restrict; +#endif + int do_syslog(int type, char __user *buf, int len, bool from_file) { unsigned i, j, limit, count; @@ -268,7 +268,20 @@ int do_syslog(int type, char __user *buf, int len, bool from_file) char c; int error = 0; - error = security_syslog(type, from_file); + /* + * If this is from /proc/kmsg we only do the capabilities checks + * at open time. + */ + if (type == SYSLOG_ACTION_OPEN || !from_file) { + if (dmesg_restrict && !capable(CAP_SYSLOG)) + goto warn; /* switch to return -EPERM after 2.6.39 */ + if ((type != SYSLOG_ACTION_READ_ALL && + type != SYSLOG_ACTION_SIZE_BUFFER) && + !capable(CAP_SYSLOG)) + goto warn; /* switch to return -EPERM after 2.6.39 */ + } + + error = security_syslog(type); if (error) return error; @@ -409,6 +422,12 @@ int do_syslog(int type, char __user *buf, int len, bool from_file) } out: return error; +warn: + /* remove after 2.6.39 */ + if (capable(CAP_SYS_ADMIN)) + WARN_ONCE(1, "Attempt to access syslog with CAP_SYS_ADMIN " + "but no CAP_SYSLOG (deprecated and denied).\n"); + return -EPERM; } SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len) @@ -1055,21 +1074,23 @@ static DEFINE_PER_CPU(int, printk_pending); void printk_tick(void) { - if (__get_cpu_var(printk_pending)) { - __get_cpu_var(printk_pending) = 0; + if (__this_cpu_read(printk_pending)) { + __this_cpu_write(printk_pending, 0); wake_up_interruptible(&log_wait); } } int printk_needs_cpu(int cpu) { - return per_cpu(printk_pending, cpu); + if (cpu_is_offline(cpu)) + printk_tick(); + return __this_cpu_read(printk_pending); } void wake_up_klogd(void) { if (waitqueue_active(&log_wait)) - __raw_get_cpu_var(printk_pending) = 1; + this_cpu_write(printk_pending, 1); } /** @@ -1338,6 +1359,7 @@ void register_console(struct console *newcon) spin_unlock_irqrestore(&logbuf_lock, flags); } release_console_sem(); + console_sysfs_notify(); /* * By unregistering the bootconsoles after we enable the real console @@ -1396,6 +1418,7 @@ int unregister_console(struct console *console) console_drivers->flags |= CON_CONSDEV; release_console_sem(); + console_sysfs_notify(); return res; } EXPORT_SYMBOL(unregister_console); |