From 09c50b4a52c01a1f450b8eec819089e228655bfb Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 20 Feb 2009 16:33:02 -0500 Subject: selinux: Fix the NetLabel glue code for setsockopt() At some point we (okay, I) managed to break the ability for users to use the setsockopt() syscall to set IPv4 options when NetLabel was not active on the socket in question. The problem was noticed by someone trying to use the "-R" (record route) option of ping: # ping -R 10.0.0.1 ping: record route: No message of desired type The solution is relatively simple, we catch the unlabeled socket case and clear the error code, allowing the operation to succeed. Please note that we still deny users the ability to override IPv4 options on socket's which have NetLabel labeling active; this is done to ensure the labeling remains intact. Signed-off-by: Paul Moore Signed-off-by: James Morris --- security/selinux/netlabel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'security') diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index f58701a7b728..3f4b26647386 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -490,8 +490,10 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, lock_sock(sk); rc = netlbl_sock_getattr(sk, &secattr); release_sock(sk); - if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + if (rc == 0) rc = -EACCES; + else if (rc == -ENOMSG) + rc = 0; netlbl_secattr_destroy(&secattr); } -- cgit v1.2.2 From d7f59dc4642ce2fc7b79fcd4ec02ffce7f21eb02 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 27 Feb 2009 15:00:03 -0500 Subject: selinux: Fix a panic in selinux_netlbl_inode_permission() Rick McNeal from LSI identified a panic in selinux_netlbl_inode_permission() caused by a certain sequence of SUNRPC operations. The problem appears to be due to the lack of NULL pointer checking in the function; this patch adds the pointer checks so the function will exit safely in the cases where the socket is not completely initialized. Signed-off-by: Paul Moore Signed-off-by: James Morris --- security/selinux/netlabel.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 3f4b26647386..350794ab9b42 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -386,11 +386,12 @@ int selinux_netlbl_inode_permission(struct inode *inode, int mask) if (!S_ISSOCK(inode->i_mode) || ((mask & (MAY_WRITE | MAY_APPEND)) == 0)) return 0; - sock = SOCKET_I(inode); sk = sock->sk; + if (sk == NULL) + return 0; sksec = sk->sk_security; - if (sksec->nlbl_state != NLBL_REQUIRE) + if (sksec == NULL || sksec->nlbl_state != NLBL_REQUIRE) return 0; local_bh_disable(); -- cgit v1.2.2 From 211a40c0870457b29100cffea0180fa5083caf96 Mon Sep 17 00:00:00 2001 From: etienne Date: Wed, 4 Mar 2009 07:33:51 +0100 Subject: smack: fixes for unlabeled host support The following patch (against 2.6.29rc5) fixes a few issues in the smack/netlabel "unlabeled host support" functionnality that was added in 2.6.29rc. It should go in before -final. 1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label), preventing 'tagged' tasks to access Internet (many systems drop packets with IP options) 2) netmasks were not handled correctly, they were stored in a way _not equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24, /32 masks but not other masks) 3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not done), so there could have been different list entries for the same IP prefix; if those entries had different labels, well ... 4) they were not sorted 1) 2) 3) are bugs, 4) is a more cosmetic issue. The patch : -creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr, -sorted by netmask length -use the new sorted nature of smack_netlbladdrs list to simplify smack_host_label : the first match _will_ be the more specific -corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show Signed-off-by: Acked-by: Casey Schaufler Reviewed-by: Paul Moore Signed-off-by: James Morris --- security/smack/smack_lsm.c | 43 ++++++------------------------- security/smack/smackfs.c | 64 +++++++++++++++++++++++++++++++++++----------- 2 files changed, 57 insertions(+), 50 deletions(-) (limited to 'security') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 0278bc083044..e7ded1326b0f 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1498,58 +1498,31 @@ static int smack_socket_post_create(struct socket *sock, int family, * looks for host based access restrictions * * This version will only be appropriate for really small - * sets of single label hosts. Because of the masking - * it cannot shortcut out on the first match. There are - * numerious ways to address the problem, but none of them - * have been applied here. + * sets of single label hosts. * * Returns the label of the far end or NULL if it's not special. */ static char *smack_host_label(struct sockaddr_in *sip) { struct smk_netlbladdr *snp; - char *bestlabel = NULL; struct in_addr *siap = &sip->sin_addr; - struct in_addr *liap; - struct in_addr *miap; - struct in_addr bestmask; if (siap->s_addr == 0) return NULL; - bestmask.s_addr = 0; - for (snp = smack_netlbladdrs; snp != NULL; snp = snp->smk_next) { - liap = &snp->smk_host.sin_addr; - miap = &snp->smk_mask; - /* - * If the addresses match after applying the list entry mask - * the entry matches the address. If it doesn't move along to - * the next entry. - */ - if ((liap->s_addr & miap->s_addr) != - (siap->s_addr & miap->s_addr)) - continue; /* - * If the list entry mask identifies a single address - * it can't get any more specific. + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match */ - if (miap->s_addr == 0xffffffff) + if ((&snp->smk_host.sin_addr)->s_addr == + (siap->s_addr & (&snp->smk_mask)->s_addr)) { return snp->smk_label; - /* - * If the list entry mask is less specific than the best - * already found this entry is uninteresting. - */ - if ((miap->s_addr | bestmask.s_addr) == bestmask.s_addr) - continue; - /* - * This is better than any entry found so far. - */ - bestmask.s_addr = miap->s_addr; - bestlabel = snp->smk_label; + } } - return bestlabel; + return NULL; } /** diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 8e42800878f4..51f0efc50dab 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -650,10 +650,6 @@ static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos) return skp; } -/* -#define BEMASK 0x80000000 -*/ -#define BEMASK 0x00000001 #define BEBITS (sizeof(__be32) * 8) /* @@ -663,12 +659,10 @@ static int netlbladdr_seq_show(struct seq_file *s, void *v) { struct smk_netlbladdr *skp = (struct smk_netlbladdr *) v; unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr; - __be32 bebits; - int maskn = 0; + int maskn; + u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr); - for (bebits = BEMASK; bebits != 0; maskn++, bebits <<= 1) - if ((skp->smk_mask.s_addr & bebits) == 0) - break; + for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++); seq_printf(s, "%u.%u.%u.%u/%d %s\n", hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label); @@ -701,6 +695,42 @@ static int smk_open_netlbladdr(struct inode *inode, struct file *file) return seq_open(file, &netlbladdr_seq_ops); } +/** + * smk_netlbladdr_insert + * @new : netlabel to insert + * + * This helper insert netlabel in the smack_netlbladdrs list + * sorted by netmask length (longest to smallest) + */ +static void smk_netlbladdr_insert(struct smk_netlbladdr *new) +{ + struct smk_netlbladdr *m; + + if (smack_netlbladdrs == NULL) { + smack_netlbladdrs = new; + return; + } + + /* the comparison '>' is a bit hacky, but works */ + if (new->smk_mask.s_addr > smack_netlbladdrs->smk_mask.s_addr) { + new->smk_next = smack_netlbladdrs; + smack_netlbladdrs = new; + return; + } + for (m = smack_netlbladdrs; m != NULL; m = m->smk_next) { + if (m->smk_next == NULL) { + m->smk_next = new; + return; + } + if (new->smk_mask.s_addr > m->smk_next->smk_mask.s_addr) { + new->smk_next = m->smk_next; + m->smk_next = new; + return; + } + } +} + + /** * smk_write_netlbladdr - write() for /smack/netlabel * @filp: file pointer, not actually used @@ -724,8 +754,9 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, struct netlbl_audit audit_info; struct in_addr mask; unsigned int m; - __be32 bebits = BEMASK; + u32 mask_bits = (1<<31); __be32 nsa; + u32 temp_mask; /* * Must have privilege. @@ -761,10 +792,13 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, if (sp == NULL) return -EINVAL; - for (mask.s_addr = 0; m > 0; m--) { - mask.s_addr |= bebits; - bebits <<= 1; + for (temp_mask = 0; m > 0; m--) { + temp_mask |= mask_bits; + mask_bits >>= 1; } + mask.s_addr = cpu_to_be32(temp_mask); + + newname.sin_addr.s_addr &= mask.s_addr; /* * Only allow one writer at a time. Writes should be * quite rare and small in any case. @@ -772,6 +806,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, mutex_lock(&smk_netlbladdr_lock); nsa = newname.sin_addr.s_addr; + /* try to find if the prefix is already in the list */ for (skp = smack_netlbladdrs; skp != NULL; skp = skp->smk_next) if (skp->smk_host.sin_addr.s_addr == nsa && skp->smk_mask.s_addr == mask.s_addr) @@ -787,9 +822,8 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, rc = 0; skp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr; skp->smk_mask.s_addr = mask.s_addr; - skp->smk_next = smack_netlbladdrs; skp->smk_label = sp; - smack_netlbladdrs = skp; + smk_netlbladdr_insert(skp); } } else { rc = netlbl_cfg_unlbl_static_del(&init_net, NULL, -- cgit v1.2.2