diff options
| -rw-r--r-- | Documentation/keys.txt | 16 | ||||
| -rw-r--r-- | security/Kconfig | 20 | ||||
| -rw-r--r-- | security/keys/proc.c | 7 |
3 files changed, 32 insertions, 11 deletions
diff --git a/Documentation/keys.txt b/Documentation/keys.txt index 3bbe157b45e4..70e83cf664ae 100644 --- a/Documentation/keys.txt +++ b/Documentation/keys.txt @@ -270,9 +270,17 @@ about the status of the key service: (*) /proc/keys - This lists all the keys on the system, giving information about their - type, description and permissions. The payload of the key is not available - this way: + This lists the keys that are currently viewable by the task reading the + file, giving information about their type, description and permissions. + It is not possible to view the payload of the key this way, though some + information about it may be given. + + The only keys included in the list are those that grant View permission to + the reading process whether or not it possesses them. Note that LSM + security checks are still performed, and may further filter out keys that + the current process is not authorised to view. + + The contents of the file look like this: SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY 00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4 @@ -300,7 +308,7 @@ about the status of the key service: (*) /proc/key-users This file lists the tracking data for each user that has at least one key - on the system. Such data includes quota information and statistics: + on the system. Such data includes quota information and statistics: [root@andromeda root]# cat /proc/key-users 0: 46 45/45 1/100 13/10000 diff --git a/security/Kconfig b/security/Kconfig index 34f593410d57..67785df264e5 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -22,16 +22,22 @@ config KEYS If you are unsure as to whether this is required, answer N. config KEYS_DEBUG_PROC_KEYS - bool "Enable the /proc/keys file by which all keys may be viewed" + bool "Enable the /proc/keys file by which keys may be viewed" depends on KEYS help - This option turns on support for the /proc/keys file through which - all the keys on the system can be listed. + This option turns on support for the /proc/keys file - through which + can be listed all the keys on the system that are viewable by the + reading process. - This option is a slight security risk in that it makes it possible - for anyone to see all the keys on the system. Normally the manager - pretends keys that are inaccessible to a process don't exist as far - as that process is concerned. + The only keys included in the list are those that grant View + permission to the reading process whether or not it possesses them. + Note that LSM security checks are still performed, and may further + filter out keys that the current process is not authorised to view. + + Only key attributes are listed here; key payloads are not included in + the resulting table. + + If you are unsure as to whether this is required, answer N. config SECURITY bool "Enable different security models" diff --git a/security/keys/proc.c b/security/keys/proc.c index 12b750e51fbf..686a9ee0c5de 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -137,6 +137,13 @@ static int proc_keys_show(struct seq_file *m, void *v) struct timespec now; unsigned long timo; char xbuf[12]; + int rc; + + /* check whether the current task is allowed to view the key (assuming + * non-possession) */ + rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW); + if (rc < 0) + return 0; now = current_kernel_time(); |