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| author | Kees Cook <kees.cook@canonical.com> | 2010-02-03 15:36:43 -0800 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2010-02-04 14:20:12 +1100 |
| commit | 002345925e6c45861f60db6f4fc6236713fd8847 (patch) | |
| tree | d7849eafe1755116597166bbebf43e2bee86cb76 /kernel/printk.c | |
| parent | 0719aaf5ead7555b7b7a4a080ebf2826a871384e (diff) | |
| download | lwn-002345925e6c45861f60db6f4fc6236713fd8847.tar.gz lwn-002345925e6c45861f60db6f4fc6236713fd8847.zip | |
syslog: distinguish between /proc/kmsg and syscalls
This allows the LSM to distinguish between syslog functions originating
from /proc/kmsg access and direct syscalls. By default, the commoncaps
will now no longer require CAP_SYS_ADMIN to read an opened /proc/kmsg
file descriptor. For example the kernel syslog reader can now drop
privileges after opening /proc/kmsg, instead of staying privileged with
CAP_SYS_ADMIN. MAC systems that implement security_syslog have unchanged
behavior.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'kernel/printk.c')
| -rw-r--r-- | kernel/printk.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index 17463ca2e229..809cf9a258a0 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -35,6 +35,7 @@ #include <linux/kexec.h> #include <linux/ratelimit.h> #include <linux/kmsg_dump.h> +#include <linux/syslog.h> #include <asm/uaccess.h> @@ -273,14 +274,14 @@ static inline void boot_delay_msec(void) * 9 -- Return number of unread characters in the log buffer * 10 -- Return size of the log buffer */ -int do_syslog(int type, char __user *buf, int len) +int do_syslog(int type, char __user *buf, int len, bool from_file) { unsigned i, j, limit, count; int do_clear = 0; char c; int error = 0; - error = security_syslog(type); + error = security_syslog(type, from_file); if (error) return error; @@ -417,7 +418,7 @@ out: SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len) { - return do_syslog(type, buf, len); + return do_syslog(type, buf, len, SYSLOG_FROM_CALL); } /* |