From 4facdf9db37c12ff655c91270d9030e2ed805ca2 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Mon, 4 Oct 2010 15:03:36 -0700 Subject: [PATCH 2/6] UBUNTU: SAUCE: AppArmor: basic networking rules Base support for network mediation. Signed-off-by: John Johansen --- security/apparmor/.gitignore | 2 +- security/apparmor/Makefile | 42 +++++++++- security/apparmor/apparmorfs.c | 1 + security/apparmor/include/audit.h | 4 + security/apparmor/include/net.h | 44 ++++++++++ security/apparmor/include/policy.h | 3 + security/apparmor/lsm.c | 112 +++++++++++++++++++++++++ security/apparmor/net.c | 162 ++++++++++++++++++++++++++++++++++++ security/apparmor/policy.c | 1 + security/apparmor/policy_unpack.c | 46 ++++++++++ 10 files changed, 414 insertions(+), 3 deletions(-) create mode 100644 security/apparmor/include/net.h create mode 100644 security/apparmor/net.c diff --git a/security/apparmor/.gitignore b/security/apparmor/.gitignore index 4d995ae..d5b291e 100644 --- a/security/apparmor/.gitignore +++ b/security/apparmor/.gitignore @@ -1,6 +1,6 @@ # # Generated include files # -af_names.h +net_names.h capability_names.h rlim_names.h diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile index 806bd19..19daa85 100644 --- a/security/apparmor/Makefile +++ b/security/apparmor/Makefile @@ -4,9 +4,9 @@ obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o apparmor-y := apparmorfs.o audit.o capability.o context.o ipc.o lib.o match.o \ path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \ - resource.o sid.o file.o + resource.o sid.o file.o net.o -clean-files := capability_names.h rlim_names.h +clean-files := capability_names.h rlim_names.h net_names.h # Build a lower case string table of capability names @@ -20,6 +20,38 @@ cmd_make-caps = echo "static const char *const capability_names[] = {" > $@ ;\ -e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/[\2] = "\L\1",/p';\ echo "};" >> $@ +# Build a lower case string table of address family names +# Transform lines from +# define AF_LOCAL 1 /* POSIX name for AF_UNIX */ +# #define AF_INET 2 /* Internet IP Protocol */ +# to +# [1] = "local", +# [2] = "inet", +# +# and build the securityfs entries for the mapping. +# Transforms lines from +# #define AF_INET 2 /* Internet IP Protocol */ +# to +# #define AA_FS_AF_MASK "local inet" +quiet_cmd_make-af = GEN $@ +cmd_make-af = echo "static const char *address_family_names[] = {" > $@ ;\ + sed $< >>$@ -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e \ + 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\ + echo "};" >> $@ ;\ + echo -n '\#define AA_FS_AF_MASK "' >> $@ ;\ + sed -r -n 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/\L\1/p'\ + $< | tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@ + +# Build a lower case string table of sock type names +# Transform lines from +# SOCK_STREAM = 1, +# to +# [1] = "stream", +quiet_cmd_make-sock = GEN $@ +cmd_make-sock = echo "static const char *sock_type_names[] = {" >> $@ ;\ + sed $^ >>$@ -r -n \ + -e 's/^\tSOCK_([A-Z0-9_]+)[\t]+=[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\ + echo "};" >> $@ # Build a lower case string table of rlimit names. # Transforms lines from @@ -56,6 +88,7 @@ cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \ tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@ $(obj)/capability.o : $(obj)/capability_names.h +$(obj)/net.o : $(obj)/net_names.h $(obj)/resource.o : $(obj)/rlim_names.h $(obj)/capability_names.h : $(srctree)/include/linux/capability.h \ $(src)/Makefile @@ -63,3 +96,8 @@ $(obj)/capability_names.h : $(srctree)/include/linux/capability.h \ $(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h \ $(src)/Makefile $(call cmd,make-rlim) +$(obj)/net_names.h : $(srctree)/include/linux/socket.h \ + $(srctree)/include/linux/net.h \ + $(src)/Makefile + $(call cmd,make-af) + $(call cmd,make-sock) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 42b7c9f..114fb23 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -429,6 +429,7 @@ static struct aa_fs_entry aa_fs_entry_domain[] = { static struct aa_fs_entry aa_fs_entry_features[] = { AA_FS_DIR("domain", aa_fs_entry_domain), AA_FS_DIR("file", aa_fs_entry_file), + AA_FS_DIR("network", aa_fs_entry_network), AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK), AA_FS_DIR("rlimit", aa_fs_entry_rlimit), { } diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h index 4b7e189..17734f9 100644 --- a/security/apparmor/include/audit.h +++ b/security/apparmor/include/audit.h @@ -127,6 +127,10 @@ struct apparmor_audit_data { u32 denied; uid_t ouid; } fs; + struct { + int type, protocol; + struct sock *sk; + } net; }; }; diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h new file mode 100644 index 0000000..cb8a121 --- /dev/null +++ b/security/apparmor/include/net.h @@ -0,0 +1,44 @@ +/* + * AppArmor security module + * + * This file contains AppArmor network mediation definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2012 Canonical Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + */ + +#ifndef __AA_NET_H +#define __AA_NET_H + +#include + +#include "apparmorfs.h" + +/* struct aa_net - network confinement data + * @allowed: basic network families permissions + * @audit_network: which network permissions to force audit + * @quiet_network: which network permissions to quiet rejects + */ +struct aa_net { + u16 allow[AF_MAX]; + u16 audit[AF_MAX]; + u16 quiet[AF_MAX]; +}; + +extern struct aa_fs_entry aa_fs_entry_network[]; + +extern int aa_net_perm(int op, struct aa_profile *profile, u16 family, + int type, int protocol, struct sock *sk); +extern int aa_revalidate_sk(int op, struct sock *sk); + +static inline void aa_free_net_rules(struct aa_net *new) +{ + /* NOP */ +} + +#endif /* __AA_NET_H */ diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index bda4569..eb13a73 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -27,6 +27,7 @@ #include "capability.h" #include "domain.h" #include "file.h" +#include "net.h" #include "resource.h" extern const char *const profile_mode_names[]; @@ -157,6 +158,7 @@ struct aa_policydb { * @policy: general match rules governing policy * @file: The set of rules governing basic file access and domain transitions * @caps: capabilities for the profile + * @net: network controls for the profile * @rlimits: rlimits for the profile * * The AppArmor profile contains the basic confinement data. Each profile @@ -194,6 +196,7 @@ struct aa_profile { struct aa_policydb policy; struct aa_file_rules file; struct aa_caps caps; + struct aa_net net; struct aa_rlimit rlimits; }; diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 8ea39aa..f628734 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -32,6 +32,7 @@ #include "include/context.h" #include "include/file.h" #include "include/ipc.h" +#include "include/net.h" #include "include/path.h" #include "include/policy.h" #include "include/procattr.h" @@ -614,6 +615,104 @@ static int apparmor_task_setrlimit(struct task_struct *task, return error; } +static int apparmor_socket_create(int family, int type, int protocol, int kern) +{ + struct aa_profile *profile; + int error = 0; + + if (kern) + return 0; + + profile = __aa_current_profile(); + if (!unconfined(profile)) + error = aa_net_perm(OP_CREATE, profile, family, type, protocol, + NULL); + return error; +} + +static int apparmor_socket_bind(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_BIND, sk); +} + +static int apparmor_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_CONNECT, sk); +} + +static int apparmor_socket_listen(struct socket *sock, int backlog) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_LISTEN, sk); +} + +static int apparmor_socket_accept(struct socket *sock, struct socket *newsock) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_ACCEPT, sk); +} + +static int apparmor_socket_sendmsg(struct socket *sock, + struct msghdr *msg, int size) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_SENDMSG, sk); +} + +static int apparmor_socket_recvmsg(struct socket *sock, + struct msghdr *msg, int size, int flags) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_RECVMSG, sk); +} + +static int apparmor_socket_getsockname(struct socket *sock) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_GETSOCKNAME, sk); +} + +static int apparmor_socket_getpeername(struct socket *sock) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_GETPEERNAME, sk); +} + +static int apparmor_socket_getsockopt(struct socket *sock, int level, + int optname) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_GETSOCKOPT, sk); +} + +static int apparmor_socket_setsockopt(struct socket *sock, int level, + int optname) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_SETSOCKOPT, sk); +} + +static int apparmor_socket_shutdown(struct socket *sock, int how) +{ + struct sock *sk = sock->sk; + + return aa_revalidate_sk(OP_SOCK_SHUTDOWN, sk); +} + static struct security_operations apparmor_ops = { .name = "apparmor", @@ -646,6 +745,19 @@ static struct security_operations apparmor_ops = { .getprocattr = apparmor_getprocattr, .setprocattr = apparmor_setprocattr, + .socket_create = apparmor_socket_create, + .socket_bind = apparmor_socket_bind, + .socket_connect = apparmor_socket_connect, + .socket_listen = apparmor_socket_listen, + .socket_accept = apparmor_socket_accept, + .socket_sendmsg = apparmor_socket_sendmsg, + .socket_recvmsg = apparmor_socket_recvmsg, + .socket_getsockname = apparmor_socket_getsockname, + .socket_getpeername = apparmor_socket_getpeername, + .socket_getsockopt = apparmor_socket_getsockopt, + .socket_setsockopt = apparmor_socket_setsockopt, + .socket_shutdown = apparmor_socket_shutdown, + .cred_alloc_blank = apparmor_cred_alloc_blank, .cred_free = apparmor_cred_free, .cred_prepare = apparmor_cred_prepare, diff --git a/security/apparmor/net.c b/security/apparmor/net.c new file mode 100644 index 0000000..003dd18 --- /dev/null +++ b/security/apparmor/net.c @@ -0,0 +1,162 @@ +/* + * AppArmor security module + * + * This file contains AppArmor network mediation + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2012 Canonical Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + */ + +#include "include/apparmor.h" +#include "include/audit.h" +#include "include/context.h" +#include "include/net.h" +#include "include/policy.h" + +#include "net_names.h" + +struct aa_fs_entry aa_fs_entry_network[] = { + AA_FS_FILE_STRING("af_mask", AA_FS_AF_MASK), + { } +}; + +/* audit callback for net specific fields */ +static void audit_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + + audit_log_format(ab, " family="); + if (address_family_names[sa->u.net->family]) { + audit_log_string(ab, address_family_names[sa->u.net->family]); + } else { + audit_log_format(ab, "\"unknown(%d)\"", sa->u.net->family); + } + audit_log_format(ab, " sock_type="); + if (sock_type_names[sa->aad->net.type]) { + audit_log_string(ab, sock_type_names[sa->aad->net.type]); + } else { + audit_log_format(ab, "\"unknown(%d)\"", sa->aad->net.type); + } + audit_log_format(ab, " protocol=%d", sa->aad->net.protocol); +} + +/** + * audit_net - audit network access + * @profile: profile being enforced (NOT NULL) + * @op: operation being checked + * @family: network family + * @type: network type + * @protocol: network protocol + * @sk: socket auditing is being applied to + * @error: error code for failure else 0 + * + * Returns: %0 or sa->error else other errorcode on failure + */ +static int audit_net(struct aa_profile *profile, int op, u16 family, int type, + int protocol, struct sock *sk, int error) +{ + int audit_type = AUDIT_APPARMOR_AUTO; + struct common_audit_data sa; + struct apparmor_audit_data aad = { }; + struct lsm_network_audit net = { }; + if (sk) { + sa.type = LSM_AUDIT_DATA_NET; + } else { + sa.type = LSM_AUDIT_DATA_NONE; + } + /* todo fill in socket addr info */ + sa.aad = &aad; + sa.u.net = &net; + sa.aad->op = op, + sa.u.net->family = family; + sa.u.net->sk = sk; + sa.aad->net.type = type; + sa.aad->net.protocol = protocol; + sa.aad->error = error; + + if (likely(!sa.aad->error)) { + u16 audit_mask = profile->net.audit[sa.u.net->family]; + if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && + !(1 << sa.aad->net.type & audit_mask))) + return 0; + audit_type = AUDIT_APPARMOR_AUDIT; + } else { + u16 quiet_mask = profile->net.quiet[sa.u.net->family]; + u16 kill_mask = 0; + u16 denied = (1 << sa.aad->net.type) & ~quiet_mask; + + if (denied & kill_mask) + audit_type = AUDIT_APPARMOR_KILL; + + if ((denied & quiet_mask) && + AUDIT_MODE(profile) != AUDIT_NOQUIET && + AUDIT_MODE(profile) != AUDIT_ALL) + return COMPLAIN_MODE(profile) ? 0 : sa.aad->error; + } + + return aa_audit(audit_type, profile, GFP_KERNEL, &sa, audit_cb); +} + +/** + * aa_net_perm - very course network access check + * @op: operation being checked + * @profile: profile being enforced (NOT NULL) + * @family: network family + * @type: network type + * @protocol: network protocol + * + * Returns: %0 else error if permission denied + */ +int aa_net_perm(int op, struct aa_profile *profile, u16 family, int type, + int protocol, struct sock *sk) +{ + u16 family_mask; + int error; + + if ((family < 0) || (family >= AF_MAX)) + return -EINVAL; + + if ((type < 0) || (type >= SOCK_MAX)) + return -EINVAL; + + /* unix domain and netlink sockets are handled by ipc */ + if (family == AF_UNIX || family == AF_NETLINK) + return 0; + + family_mask = profile->net.allow[family]; + + error = (family_mask & (1 << type)) ? 0 : -EACCES; + + return audit_net(profile, op, family, type, protocol, sk, error); +} + +/** + * aa_revalidate_sk - Revalidate access to a sock + * @op: operation being checked + * @sk: sock being revalidated (NOT NULL) + * + * Returns: %0 else error if permission denied + */ +int aa_revalidate_sk(int op, struct sock *sk) +{ + struct aa_profile *profile; + int error = 0; + + /* aa_revalidate_sk should not be called from interrupt context + * don't mediate these calls as they are not task related + */ + if (in_interrupt()) + return 0; + + profile = __aa_current_profile(); + if (!unconfined(profile)) + error = aa_net_perm(op, profile, sk->sk_family, sk->sk_type, + sk->sk_protocol, sk); + + return error; +} diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index cf5fd22..27c8161 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -745,6 +745,7 @@ static void free_profile(struct aa_profile *profile) aa_free_file_rules(&profile->file); aa_free_cap_rules(&profile->caps); + aa_free_net_rules(&profile->net); aa_free_rlimit_rules(&profile->rlimits); aa_free_sid(profile->sid); diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 329b1fd..1b90dfa 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -193,6 +193,19 @@ fail: return 0; } +static bool unpack_u16(struct aa_ext *e, u16 *data, const char *name) +{ + if (unpack_nameX(e, AA_U16, name)) { + if (!inbounds(e, sizeof(u16))) + return 0; + if (data) + *data = le16_to_cpu(get_unaligned((u16 *) e->pos)); + e->pos += sizeof(u16); + return 1; + } + return 0; +} + static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name) { if (unpack_nameX(e, AA_U32, name)) { @@ -471,6 +484,7 @@ static struct aa_profile *unpack_profile(struct aa_ext *e) { struct aa_profile *profile = NULL; const char *name = NULL; + size_t size = 0; int i, error = -EPROTO; kernel_cap_t tmpcap; u32 tmp; @@ -564,6 +578,38 @@ static struct aa_profile *unpack_profile(struct aa_ext *e) if (!unpack_rlimits(e, profile)) goto fail; + size = unpack_array(e, "net_allowed_af"); + if (size) { + + for (i = 0; i < size; i++) { + /* discard extraneous rules that this kernel will + * never request + */ + if (i >= AF_MAX) { + u16 tmp; + if (!unpack_u16(e, &tmp, NULL) || + !unpack_u16(e, &tmp, NULL) || + !unpack_u16(e, &tmp, NULL)) + goto fail; + continue; + } + if (!unpack_u16(e, &profile->net.allow[i], NULL)) + goto fail; + if (!unpack_u16(e, &profile->net.audit[i], NULL)) + goto fail; + if (!unpack_u16(e, &profile->net.quiet[i], NULL)) + goto fail; + } + if (!unpack_nameX(e, AA_ARRAYEND, NULL)) + goto fail; + } + /* + * allow unix domain and netlink sockets they are handled + * by IPC + */ + profile->net.allow[AF_UNIX] = 0xffff; + profile->net.allow[AF_NETLINK] = 0xffff; + if (unpack_nameX(e, AA_STRUCT, "policydb")) { /* generic policy dfa - optional and may be NULL */ profile->policy.dfa = unpack_dfa(e); -- 1.7.10.4