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authorEric Paris <eparis@redhat.com>2010-11-15 18:36:29 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-11-15 15:40:01 -0800
commit12b3052c3ee8f508b2c7ee4ddd63ed03423409d8 (patch)
treeb97d0f209f363cfad94ce9d075312274e349da89 /kernel/printk.c
parent6800e4c0ea3e96cf78953b8b5743381cb1bb9e37 (diff)
downloadlinux-12b3052c3ee8f508b2c7ee4ddd63ed03423409d8.tar.bz2
capabilities/syslog: open code cap_syslog logic to fix build failure
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build failure when CONFIG_PRINTK=n. This is because the capabilities code which used the new option was built even though the variable in question didn't exist. The patch here fixes this by moving the capabilities checks out of the LSM and into the caller. All (known) LSMs should have been calling the capabilities hook already so it actually makes the code organization better to eliminate the hook altogether. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/printk.c')
-rw-r--r--kernel/printk.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index 38e7d5868d60..9a2264fc42ca 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -274,7 +274,20 @@ 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_SYS_ADMIN))
+ return -EPERM;
+ if ((type != SYSLOG_ACTION_READ_ALL &&
+ type != SYSLOG_ACTION_SIZE_BUFFER) &&
+ !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ }
+
+ error = security_syslog(type);
if (error)
return error;