Re: [PATCH 3/3] audit: drop audit_cmd_lock in AUDIT_USER family of cases
On Wed, 4 Dec 2013 21:45:56 -0500 Richard Guy Briggs wrote: > We do not need to hold the audit_cmd_mutex for this family of cases. The > possible exception to this is the call to audit_filter_user(), so drop the > lock > immediately after. To help in fixing the race we are trying to avoid, make > sure that nothing called by audit_filter_user() calls audit_log_start(). In > particular, watch out for *_audit_rule_match(). > > This fix will take care of systemd and anything USING audit. It still means > that we could race with something configuring audit and auditd shutting down. > > Signed-off-by: Richard Guy Briggs > Signed-off-by: Richard Guy Briggs When I have tested a patch with my reproducer, a hangup by this problem doesn't occur. reproducer # auditctl -a exit,always -S all # reboot / So, this fix looks good to me. Please add: Reported-by: toshi.okaj...@jp.fujitsu.com Tested-by: toshi.okaj...@jp.fujitsu.com Thanks. > --- > kernel/audit.c |2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/kernel/audit.c b/kernel/audit.c > index 4689012..4cbc945 100644 > --- a/kernel/audit.c > +++ b/kernel/audit.c > @@ -713,6 +713,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct > nlmsghdr *nlh) > if (err) > break; > } > + mutex_unlock(_cmd_mutex); > audit_log_common_recv_msg(, msg_type); > if (msg_type != AUDIT_USER_TTY) > audit_log_format(ab, " msg='%.1024s'", > @@ -729,6 +730,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct > nlmsghdr *nlh) > } > audit_set_pid(ab, NETLINK_CB(skb).portid); > audit_log_end(ab); > + mutex_lock(_cmd_mutex); > } > break; > case AUDIT_ADD_RULE: > -- > 1.7.1 > -- Toshiyuki Okajima -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] audit: drop audit_cmd_lock in AUDIT_USER family of cases
On Wed, 4 Dec 2013 21:45:56 -0500 Richard Guy Briggs r...@redhat.com wrote: We do not need to hold the audit_cmd_mutex for this family of cases. The possible exception to this is the call to audit_filter_user(), so drop the lock immediately after. To help in fixing the race we are trying to avoid, make sure that nothing called by audit_filter_user() calls audit_log_start(). In particular, watch out for *_audit_rule_match(). This fix will take care of systemd and anything USING audit. It still means that we could race with something configuring audit and auditd shutting down. Signed-off-by: Richard Guy Briggs r...@tricolour.ca Signed-off-by: Richard Guy Briggs r...@redhat.com When I have tested a patch with my reproducer, a hangup by this problem doesn't occur. reproducer # auditctl -a exit,always -S all # reboot / So, this fix looks good to me. Please add: Reported-by: toshi.okaj...@jp.fujitsu.com Tested-by: toshi.okaj...@jp.fujitsu.com Thanks. --- kernel/audit.c |2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 4689012..4cbc945 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -713,6 +713,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } + mutex_unlock(audit_cmd_mutex); audit_log_common_recv_msg(ab, msg_type); if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, msg='%.1024s', @@ -729,6 +730,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } audit_set_pid(ab, NETLINK_CB(skb).portid); audit_log_end(ab); + mutex_lock(audit_cmd_mutex); } break; case AUDIT_ADD_RULE: -- 1.7.1 -- Toshiyuki Okajima toshi.okaj...@jp.fujitsu.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] audit: drop audit_cmd_lock in AUDIT_USER family of cases
We do not need to hold the audit_cmd_mutex for this family of cases. The possible exception to this is the call to audit_filter_user(), so drop the lock immediately after. To help in fixing the race we are trying to avoid, make sure that nothing called by audit_filter_user() calls audit_log_start(). In particular, watch out for *_audit_rule_match(). This fix will take care of systemd and anything USING audit. It still means that we could race with something configuring audit and auditd shutting down. Signed-off-by: Richard Guy Briggs Signed-off-by: Richard Guy Briggs --- kernel/audit.c |2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 4689012..4cbc945 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -713,6 +713,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } + mutex_unlock(_cmd_mutex); audit_log_common_recv_msg(, msg_type); if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, " msg='%.1024s'", @@ -729,6 +730,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } audit_set_pid(ab, NETLINK_CB(skb).portid); audit_log_end(ab); + mutex_lock(_cmd_mutex); } break; case AUDIT_ADD_RULE: -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] audit: drop audit_cmd_lock in AUDIT_USER family of cases
We do not need to hold the audit_cmd_mutex for this family of cases. The possible exception to this is the call to audit_filter_user(), so drop the lock immediately after. To help in fixing the race we are trying to avoid, make sure that nothing called by audit_filter_user() calls audit_log_start(). In particular, watch out for *_audit_rule_match(). This fix will take care of systemd and anything USING audit. It still means that we could race with something configuring audit and auditd shutting down. Signed-off-by: Richard Guy Briggs r...@tricolour.ca Signed-off-by: Richard Guy Briggs r...@redhat.com --- kernel/audit.c |2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 4689012..4cbc945 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -713,6 +713,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } + mutex_unlock(audit_cmd_mutex); audit_log_common_recv_msg(ab, msg_type); if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, msg='%.1024s', @@ -729,6 +730,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } audit_set_pid(ab, NETLINK_CB(skb).portid); audit_log_end(ab); + mutex_lock(audit_cmd_mutex); } break; case AUDIT_ADD_RULE: -- 1.7.1 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
