kernel/linux.git/security/selinux/hooks.c, branch linux-4.4.y

selinux: initialize proto variable in selinux_ip_postroute_compat()

2022-01-05T11:30:27+00:00

commit 732bc2ff080c447f8524f40c970c481f5da6eed3 upstream. Clang static analysis reports this warning hooks.c:5765:6: warning: 4th function call argument is an uninitialized value if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ selinux_parse_skb() can return ok without setting proto. The later call to selinux_xfrm_postroute_last() does an early check of proto and can return ok if the garbage proto value matches. So initialize proto. Cc: stable@vger.kernel.org Fixes: eef9b41622f2 ("selinux: cleanup selinux_xfrm_sock_rcv_skb() and selinux_xfrm_postroute_last()") Signed-off-by: Tom Rix [PM: typo/spelling and checkpatch.pl description fixes] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

binder: use cred instead of task for selinux checks

2021-11-26T10:58:33+00:00

commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn Signed-off-by: Todd Kjos Acked-by: Casey Schaufler Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: properly handle multiple messages in selinux_netlink_send()

2020-05-05T17:13:25+00:00

commit fb73974172ffaaf57a7c42f35424d9aece1a5af6 upstream. Fix the SELinux netlink_send hook to properly handle multiple netlink messages in a single sk_buff; each message is parsed and subject to SELinux access control. Prior to this patch, SELinux only inspected the first message in the sk_buff. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov Reviewed-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: never allow relabeling on context mounts

2019-05-16T17:45:03+00:00

commit a83d6ddaebe541570291205cb538e35ad4ff94f9 upstream. In the SECURITY_FS_USE_MNTPOINT case we never want to allow relabeling files/directories, so we should never set the SBLABEL_MNT flag. The 'special handling' in selinux_is_sblabel_mnt() is only intended for when the behavior is set to SECURITY_FS_USE_GENFS. While there, make the logic in selinux_is_sblabel_mnt() more explicit and add a BUILD_BUG_ON() to make sure that introducing a new SECURITY_FS_USE_* forces a review of the logic. Fixes: d5f3a5f6e7e7 ("selinux: add security in-core xattr support for pstore and debugfs") Signed-off-by: Ondrej Mosnacek Reviewed-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: do not check open permission on sockets

2018-04-13T17:50:10+00:00

[ Upstream commit ccb544781d34afdb73a9a73ae53035d824d193bf ] open permission is currently only defined for files in the kernel (COMMON_FILE_PERMS rather than COMMON_FILE_SOCK_PERMS). Construction of an artificial test case that tries to open a socket via /proc/pid/fd will generate a recvfrom avc denial because recvfrom and open happen to map to the same permission bit in socket vs file classes. open of a socket via /proc/pid/fd is not supported by the kernel regardless and will ultimately return ENXIO. But we hit the permission check first and can thus produce these odd/misleading denials. Omit the open check when operating on a socket. Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

selinux: Remove redundant check for unknown labeling behavior

2018-04-08T09:51:58+00:00

commit 270e8573145a26de924e2dc644596332d400445b upstream. The check is already performed in ocontext_read() when the policy is loaded. Removing the array also fixes the following warning when building with clang: security/selinux/hooks.c:338:20: error: variable 'labeling_behaviors' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] Signed-off-by: Matthias Kaehlcke Acked-by: Stephen Smalley Signed-off-by: Paul Moore [natechancellor: inode_doinit_with_dentry still present] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

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: 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 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 ...