On 12/7/2015 1:25 PM, Jann Horn wrote:
It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.
Signed-off-by: Jann Horn <jann@xxxxxxxxx>
Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
security/smack/smack_lsm.c | 8 +++-----
security/yama/yama_lsm.c | 4 ++--
2 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index ff81026..7c57c7f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -398,12 +398,10 @@ static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
*/
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
- switch (mode) {
- case PTRACE_MODE_READ:
- return MAY_READ;
- case PTRACE_MODE_ATTACH:
+ if (mode & PTRACE_MODE_ATTACH)
return MAY_READWRITE;
- }
+ if (mode & PTRACE_MODE_READ)
+ return MAY_READ;
return 0;
}
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index d3c19c9..cb6ed10 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -281,7 +281,7 @@ static int yama_ptrace_access_check(struct task_struct *child,
int rc = 0;
/* require ptrace target be a child of ptracer on attach */
- if (mode == PTRACE_MODE_ATTACH) {
+ if (mode & PTRACE_MODE_ATTACH) {
switch (ptrace_scope) {
case YAMA_SCOPE_DISABLED:
/* No additional restrictions. */
@@ -307,7 +307,7 @@ static int yama_ptrace_access_check(struct task_struct *child,
}
}
- if (rc) {
+ if (rc && (mode & PTRACE_MODE_NOAUDIT) == 0) {
printk_ratelimited(KERN_NOTICE
"ptrace of pid %d was attempted by: %s (pid %d)\n",
child->pid, current->comm, current->pid);
--
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