From 50397bd1e471391d27f64efad9271459c913de87 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Mon, 7 Jan 2008 18:14:19 -0500 Subject: [AUDIT] clean up audit_receive_msg() generally clean up audit_receive_msg() don't free random memory if selinux_sid_to_string fails for some reason. Move generic auditing to a helper function Signed-off-by: Eric Paris diff --git a/kernel/audit.c b/kernel/audit.c index 7e29372..549b2f5 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -152,8 +152,10 @@ struct audit_buffer { static void audit_set_pid(struct audit_buffer *ab, pid_t pid) { - struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); - nlh->nlmsg_pid = pid; + if (ab) { + struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); + nlh->nlmsg_pid = pid; + } } void audit_panic(const char *message) @@ -511,6 +513,33 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) return err; } +static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, + u32 pid, u32 uid, uid_t auid, u32 sid) +{ + int rc = 0; + char *ctx = NULL; + u32 len; + + if (!audit_enabled) { + *ab = NULL; + return rc; + } + + *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); + audit_log_format(*ab, "user pid=%d uid=%u auid=%u", + pid, uid, auid); + if (sid) { + rc = selinux_sid_to_string(sid, &ctx, &len); + if (rc) + audit_log_format(*ab, " ssid=%u", sid); + else + audit_log_format(*ab, " subj=%s", ctx); + kfree(ctx); + } + + return rc; +} + static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { u32 uid, pid, seq, sid; @@ -521,7 +550,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) u16 msg_type = nlh->nlmsg_type; uid_t loginuid; /* loginuid of sender */ struct audit_sig_info *sig_data; - char *ctx; + char *ctx = NULL; u32 len; err = audit_netlink_ok(skb, msg_type); @@ -602,36 +631,22 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } - ab = audit_log_start(NULL, GFP_KERNEL, msg_type); - if (ab) { - audit_log_format(ab, - "user pid=%d uid=%u auid=%u", - pid, uid, loginuid); - if (sid) { - if (selinux_sid_to_string( - sid, &ctx, &len)) { - audit_log_format(ab, - " ssid=%u", sid); - /* Maybe call audit_panic? */ - } else - audit_log_format(ab, - " subj=%s", ctx); - kfree(ctx); - } - if (msg_type != AUDIT_USER_TTY) - audit_log_format(ab, " msg='%.1024s'", - (char *)data); - else { - int size; - - audit_log_format(ab, " msg="); - size = nlmsg_len(nlh); - audit_log_n_untrustedstring(ab, size, - data); - } - audit_set_pid(ab, pid); - audit_log_end(ab); + audit_log_common_recv_msg(&ab, msg_type, pid, uid, + loginuid, sid); + + if (msg_type != AUDIT_USER_TTY) + audit_log_format(ab, " msg='%.1024s'", + (char *)data); + else { + int size; + + audit_log_format(ab, " msg="); + size = nlmsg_len(nlh); + audit_log_n_untrustedstring(ab, size, + data); } + audit_set_pid(ab, pid); + audit_log_end(ab); } break; case AUDIT_ADD: @@ -639,27 +654,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (nlmsg_len(nlh) < sizeof(struct audit_rule)) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { - ab = audit_log_start(NULL, GFP_KERNEL, - AUDIT_CONFIG_CHANGE); - if (ab) { - audit_log_format(ab, - "pid=%d uid=%u auid=%u", - pid, uid, loginuid); - if (sid) { - if (selinux_sid_to_string( - sid, &ctx, &len)) { - audit_log_format(ab, - " ssid=%u", sid); - /* Maybe call audit_panic? */ - } else - audit_log_format(ab, - " subj=%s", ctx); - kfree(ctx); - } - audit_log_format(ab, " audit_enabled=%d res=0", - audit_enabled); - audit_log_end(ab); - } + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + + audit_log_format(ab, " audit_enabled=%d res=0", + audit_enabled); + audit_log_end(ab); return -EPERM; } /* fallthrough */ @@ -673,27 +673,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { - ab = audit_log_start(NULL, GFP_KERNEL, - AUDIT_CONFIG_CHANGE); - if (ab) { - audit_log_format(ab, - "pid=%d uid=%u auid=%u", - pid, uid, loginuid); - if (sid) { - if (selinux_sid_to_string( - sid, &ctx, &len)) { - audit_log_format(ab, - " ssid=%u", sid); - /* Maybe call audit_panic? */ - } else - audit_log_format(ab, - " subj=%s", ctx); - kfree(ctx); - } - audit_log_format(ab, " audit_enabled=%d res=0", - audit_enabled); - audit_log_end(ab); - } + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + + audit_log_format(ab, " audit_enabled=%d res=0", + audit_enabled); + audit_log_end(ab); return -EPERM; } /* fallthrough */ @@ -704,19 +689,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) break; case AUDIT_TRIM: audit_trim_trees(); - ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - if (!ab) - break; - audit_log_format(ab, "auid=%u", loginuid); - if (sid) { - u32 len; - ctx = NULL; - if (selinux_sid_to_string(sid, &ctx, &len)) - audit_log_format(ab, " ssid=%u", sid); - else - audit_log_format(ab, " subj=%s", ctx); - kfree(ctx); - } + + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + audit_log_format(ab, " op=trim res=1"); audit_log_end(ab); break; @@ -746,22 +722,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* OK, here comes... */ err = audit_tag_tree(old, new); - ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - if (!ab) { - kfree(old); - kfree(new); - break; - } - audit_log_format(ab, "auid=%u", loginuid); - if (sid) { - u32 len; - ctx = NULL; - if (selinux_sid_to_string(sid, &ctx, &len)) - audit_log_format(ab, " ssid=%u", sid); - else - audit_log_format(ab, " subj=%s", ctx); - kfree(ctx); - } + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + audit_log_format(ab, " op=make_equiv old="); audit_log_untrustedstring(ab, old); audit_log_format(ab, " new="); -- cgit v0.10.2