Commit dd099793 authored Mar 07, 2012 by Nick Kralevich Committed by Greg Kroah-Hartman Mar 08, 2012

staging: android: ram_console: honor dmesg_restrict



The Linux kernel has a setting called dmesg_restrict. When true,
only processes with CAP_SYSLOG can view the kernel dmesg logs. This
helps prevent leaking of kernel information into user space.

On Android, it's possible to bypass these restrictions by viewing
/proc/last_kmsg.

This change makes /proc/last_kmsg require the same permissions as
dmesg.

CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Nick Kralevich <nnk@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3a21138d

drivers/staging/android/ram_console.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -99,6 +99,9 @@ static ssize_t ram_console_read_old(struct file file, char __user buf,
		char *str;
		int ret;

		if (dmesg_restrict && !capable(CAP_SYSLOG))
		return -EPERM;

		/* Main last_kmsg log */
		if (pos < old_log_size) {
		count = min(len, (size_t)(old_log_size - pos));