kernel/linux.git/security/selinux, branch v4.4.123

selinux: check for address length in selinux_socket_bind()

2018-03-22T08:23:20+00:00

[ Upstream commit e2f586bd83177d22072b275edd4b8b872daba924 ] KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of uninitialized memory in selinux_socket_bind(): ================================================================== BUG: KMSAN: use of unitialized memory inter: 0 CPU: 3 PID: 1074 Comm: packet2 Tainted: G B 4.8.0-rc6+ #1916 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 0000000000000000 ffff8800882ffb08 ffffffff825759c8 ffff8800882ffa48 ffffffff818bf551 ffffffff85bab870 0000000000000092 ffffffff85bab550 0000000000000000 0000000000000092 00000000bb0009bb 0000000000000002 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x238/0x290 lib/dump_stack.c:51 [] kmsan_report+0x276/0x2e0 mm/kmsan/kmsan.c:1008 [] __msan_warning+0x5b/0xb0 mm/kmsan/kmsan_instr.c:424 [] selinux_socket_bind+0xf41/0x1080 security/selinux/hooks.c:4288 [] security_socket_bind+0x1ec/0x240 security/security.c:1240 [] SYSC_bind+0x358/0x5f0 net/socket.c:1366 [] SyS_bind+0x82/0xa0 net/socket.c:1356 [] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [] entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.o:? chained origin: 00000000ba6009bb [] save_stack_trace+0x27/0x50 arch/x86/kernel/stacktrace.c:67 [< inline >] kmsan_save_stack_with_flags mm/kmsan/kmsan.c:322 [< inline >] kmsan_save_stack mm/kmsan/kmsan.c:337 [] kmsan_internal_chain_origin+0x118/0x1e0 mm/kmsan/kmsan.c:530 [] __msan_set_alloca_origin4+0xc3/0x130 mm/kmsan/kmsan_instr.c:380 [] SYSC_bind+0x129/0x5f0 net/socket.c:1356 [] SyS_bind+0x82/0xa0 net/socket.c:1356 [] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [] return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.o:? origin description: ----address@SYSC_bind (origin=00000000b8c00900) ================================================================== (the line numbers are relative to 4.8-rc6, but the bug persists upstream) , when I run the following program as root: ======================================================= #include #include #include int main(int argc, char *argv[]) { struct sockaddr addr; int size = 0; if (argc > 1) { size = atoi(argv[1]); } memset(&addr, 0, sizeof(addr)); int fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP); bind(fd, &addr, size); return 0; } ======================================================= (for different values of |size| other error reports are printed). This happens because bind() unconditionally copies |size| bytes of |addr| to the kernel, leaving the rest uninitialized. Then security_socket_bind() reads the IP address bytes, including the uninitialized ones, to determine the port, or e.g. pass them further to sel_netnode_find(), which uses them to calculate a hash. Signed-off-by: Alexander Potapenko Acked-by: Eric Dumazet [PM: fixed some whitespace damage] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

selinux: skip bounded transition processing if the policy isn't loaded

2018-02-25T10:03:36+00:00

commit 4b14752ec4e0d87126e636384cf37c8dd9df157c upstream. We can't do anything reasonable in security_bounded_transition() if we don't have a policy loaded, and in fact we could run into problems with some of the code inside expecting a policy. Fix these problems like we do many others in security/selinux/ss/services.c by checking to see if the policy is loaded (ss_initialized) and returning quickly if it isn't. Reported-by: syzbot Signed-off-by: Paul Moore Acked-by: Stephen Smalley Reviewed-by: James Morris Signed-off-by: Greg Kroah-Hartman

selinux: ensure the context is NUL terminated in security_context_to_sid_core()

2018-02-25T10:03:36+00:00

commit ef28df55ac27e1e5cd122e19fa311d886d47a756 upstream. The syzbot/syzkaller automated tests found a problem in security_context_to_sid_core() during early boot (before we load the SELinux policy) where we could potentially feed context strings without NUL terminators into the strcmp() function. We already guard against this during normal operation (after the SELinux policy has been loaded) by making a copy of the context strings and explicitly adding a NUL terminator to the end. The patch extends this protection to the early boot case (no loaded policy) by moving the context copy earlier in security_context_to_sid_core(). Reported-by: syzbot Signed-off-by: Paul Moore Reviewed-By: William Roberts Signed-off-by: Greg Kroah-Hartman

selinux: general protection fault in sock_has_perm

2018-02-03T16:04:30+00:00

In the absence of commit a4298e4522d6 ("net: add SOCK_RCU_FREE socket flag") and all the associated infrastructure changes to take advantage of a RCU grace period before freeing, there is a heightened possibility that a security check is performed while an ill-timed setsockopt call races in from user space. It then is prudent to null check sk_security, and if the case, reject the permissions. Because of the nature of this problem, hard to duplicate, no clear path, this patch is a simplified band-aid for stable trees lacking the infrastructure for the series of commits leading up to providing a suitable RCU grace period. This adjustment is orthogonal to infrastructure improvements that may nullify the needed check, but could be added as good code hygiene in all trees. general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 14233 Comm: syz-executor2 Not tainted 4.4.112-g5f6325b #28 task: ffff8801d1095f00 task.stack: ffff8800b5950000 RIP: 0010:[] [] sock_has_perm+0x1fe/0x3e0 security/selinux/hooks.c:4069 RSP: 0018:ffff8800b5957ce0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 1ffff10016b2af9f RCX: ffffffff81b69b51 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000010 RBP: ffff8800b5957de0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 1ffff10016b2af68 R12: ffff8800b5957db8 R13: 0000000000000000 R14: ffff8800b7259f40 R15: 00000000000000d7 FS: 00007f72f5ae2700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000a2fa38 CR3: 00000001d7980000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff81b69a1f ffff8800b5957d58 00008000b5957d30 0000000041b58ab3 ffffffff83fc82f2 ffffffff81b69980 0000000000000246 ffff8801d1096770 ffff8801d3165668 ffffffff8157844b ffff8801d1095f00 ffff880000000001 Call Trace: [] selinux_socket_setsockopt+0x4d/0x80 security/selinux/hooks.c:4338 [] security_socket_setsockopt+0x7d/0xb0 security/security.c:1257 [] SYSC_setsockopt net/socket.c:1757 [inline] [] SyS_setsockopt+0xe8/0x250 net/socket.c:1746 [] entry_SYSCALL_64_fastpath+0x16/0x92 Code: c2 42 9b b6 81 be 01 00 00 00 48 c7 c7 a0 cb 2b 84 e8 f7 2f 6d ff 49 8d 7d 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 83 01 00 00 41 8b 75 10 31 RIP [] sock_has_perm+0x1fe/0x3e0 security/selinux/hooks.c:4069 RSP ---[ end trace 7b5aaf788fef6174 ]--- Signed-off-by: Mark Salyzyn Acked-by: Paul Moore Cc: Eric Dumazet Cc: Stephen Smalley Cc: selinux@tycho.nsa.gov Cc: linux-security-module@vger.kernel.org Cc: Eric Paris Cc: Serge E. Hallyn Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

selinux: fix off-by-one in setprocattr

2017-02-14T23:22:50+00:00

commit 0c461cb727d146c9ef2d3e86214f498b78b7d125 upstream. SELinux tries to support setting/clearing of /proc/pid/attr attributes from the shell by ignoring terminating newlines and treating an attribute value that begins with a NUL or newline as an attempt to clear the attribute. However, the test for clearing attributes has always been wrong; it has an off-by-one error, and this could further lead to reading past the end of the allocated buffer since commit bb646cdb12e75d82258c2f2e7746d5952d3e321a ("proc_pid_attr_write(): switch to memdup_user()"). Fix the off-by-one error. Even with this fix, setting and clearing /proc/pid/attr attributes from the shell is not straightforward since the interface does not support multiple write() calls (so shells that write the value and newline separately will set and then immediately clear the attribute, requiring use of echo -n to set the attribute), whereas trying to use echo -n "" to clear the attribute causes the shell to skip the write() call altogether since POSIX says that a zero-length write causes no side effects. Thus, one must use echo -n to set and echo without -n to clear, as in the following example: $ echo -n unconfined_u:object_r:user_home_t:s0 > /proc/$$/attr/fscreate $ cat /proc/$$/attr/fscreate unconfined_u:object_r:user_home_t:s0 $ echo "" > /proc/$$/attr/fscreate $ cat /proc/$$/attr/fscreate Note the use of /proc/$$ rather than /proc/self, as otherwise the cat command will read its own attribute value, not that of the shell. There are no users of this facility to my knowledge; possibly we should just get rid of it. UPDATE: Upon further investigation it appears that a local process with the process:setfscreate permission can cause a kernel panic as a result of this bug. This patch fixes CVE-2017-2618. Signed-off-by: Stephen Smalley [PM: added the update about CVE-2017-2618 to the commit description] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman Signed-off-by: James Morris

Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/selinux into for-linus2

2015-11-26T04:04:19+00:00

selinux: fix bug in conditional rules handling

2015-11-24T18:44:32+00:00

commit fa1aa143ac4a ("selinux: extended permissions for ioctls") introduced a bug into the handling of conditional rules, skipping the processing entirely when the caller does not provide an extended permissions (xperms) structure. Access checks from userspace using /sys/fs/selinux/access do not include such a structure since that interface does not presently expose extended permission information. As a result, conditional rules were being ignored entirely on userspace access requests, producing denials when access was allowed by conditional rules in the policy. Fix the bug by only skipping computation of extended permissions in this situation, not the entire conditional rules processing. Reported-by: Laurent Bigonville Signed-off-by: Stephen Smalley [PM: fixed long lines in patch description] Cc: stable@vger.kernel.org # 4.3 Signed-off-by: Paul Moore

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-11-11T02:11:41+00:00

Pull networking fixes from David Miller: 1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet. 2) Several spots need to get to the original listner for SYN-ACK packets, most spots got this ok but some were not. Whilst covering the remaining cases, create a helper to do this. From Eric Dumazet. 3) Missiing check of return value from alloc_netdev() in CAIF SPI code, from Rasmus Villemoes. 4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich. 5) Use after free in mvneta driver, from Justin Maggard. 6) Fix race on dst->flags access in dst_release(), from Eric Dumazet. 7) Add missing ZLIB_INFLATE dependency for new qed driver. From Arnd Bergmann. 8) Fix multicast getsockopt deadlock, from WANG Cong. 9) Fix deadlock in btusb, from Kuba Pawlak. 10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6 counter state. From Sabrina Dubroca. 11) Fix packet_bind() race, which can cause lost notifications, from Francesco Ruggeri. 12) Fix MAC restoration in qlcnic driver during bonding mode changes, from Jarod Wilson. 13) Revert bridging forward delay change which broke libvirt and other userspace things, from Vlad Yasevich. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits) Revert "bridge: Allow forward delay to be cfgd when STP enabled" bpf_trace: Make dependent on PERF_EVENTS qed: select ZLIB_INFLATE net: fix a race in dst_release() net: mvneta: Fix memory use after free. net: Documentation: Fix default value tcp_limit_output_bytes macvtap: Resolve possible __might_sleep warning in macvtap_do_read() mvneta: add FIXED_PHY dependency net: caif: check return value of alloc_netdev net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA drivers: net: xgene: fix RGMII 10/100Mb mode netfilter: nft_meta: use skb_to_full_sk() helper net_sched: em_meta: use skb_to_full_sk() helper sched: cls_flow: use skb_to_full_sk() helper netfilter: xt_owner: use skb_to_full_sk() helper smack: use skb_to_full_sk() helper net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid() bpf: doc: correct arch list for supported eBPF JIT dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put" bonding: fix panic on non-ARPHRD_ETHER enslave failure ...

net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()

2015-11-09T01:56:38+00:00

Generalize selinux_skb_sk() added in commit 212cd0895330 ("selinux: fix random read in selinux_ip_postroute_compat()") so that we can use it other contexts. Use it right away in selinux_netlbl_skbuff_setsid() Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2015-11-05T23:32:38+00:00

Pull security subsystem update from James Morris: "This is mostly maintenance updates across the subsystem, with a notable update for TPM 2.0, and addition of Jarkko Sakkinen as a maintainer of that" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits) apparmor: clarify CRYPTO dependency selinux: Use a kmem_cache for allocation struct file_security_struct selinux: ioctl_has_perm should be static selinux: use sprintf return value selinux: use kstrdup() in security_get_bools() selinux: use kmemdup in security_sid_to_context_core() selinux: remove pointless cast in selinux_inode_setsecurity() selinux: introduce security_context_str_to_sid selinux: do not check open perm on ftruncate call selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default KEYS: Merge the type-specific data with the payload data KEYS: Provide a script to extract a module signature KEYS: Provide a script to extract the sys cert list from a vmlinux file keys: Be more consistent in selection of union members used certs: add .gitignore to stop git nagging about x509_certificate_list KEYS: use kvfree() in add_key Smack: limited capability for changing process label TPM: remove unnecessary little endian conversion vTPM: support little endian guests char: Drop owner assignment from i2c_driver ...