linux/security, branch v3.4.80

SELinux: Fix memory leak upon loading policy

2014-02-13T19:51:07Z

commit 8ed814602876bec9bad2649ca17f34b499357a1c upstream. Hello. I got below leak with linux-3.10.0-54.0.1.el7.x86_64 . [ 681.903890] kmemleak: 5538 new suspected memory leaks (see /sys/kernel/debug/kmemleak) Below is a patch, but I don't know whether we need special handing for undoing ebitmap_set_bit() call. ---------- >>From fe97527a90fe95e2239dfbaa7558f0ed559c0992 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 6 Jan 2014 16:30:21 +0900 Subject: SELinux: Fix memory leak upon loading policy Commit 2463c26d "SELinux: put name based create rules in a hashtable" did not check return value from hashtab_insert() in filename_trans_read(). It leaks memory if hashtab_insert() returns error. unreferenced object 0xffff88005c9160d0 (size 8): comm "systemd", pid 1, jiffies 4294688674 (age 235.265s) hex dump (first 8 bytes): 57 0b 00 00 6b 6b 6b a5 W...kkk. backtrace: [] kmemleak_alloc+0x4e/0xb0 [] kmem_cache_alloc_trace+0x12e/0x360 [] policydb_read+0xd1d/0xf70 [] security_load_policy+0x6c/0x500 [] sel_write_load+0xac/0x750 [] vfs_write+0xc0/0x1f0 [] SyS_write+0x4c/0xa0 [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff However, we should not return EEXIST error to the caller, or the systemd will show below message and the boot sequence freezes. systemd[1]: Failed to load SELinux policy. Freezing. Signed-off-by: Tetsuo Handa Acked-by: Eric Paris Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

SELinux: Fix possible NULL pointer dereference in selinux_inode_permission()

2014-01-29T13:10:42Z

commit 3dc91d4338d698ce77832985f9cb183d8eeaf6be upstream. While running stress tests on adding and deleting ftrace instances I hit this bug: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: selinux_inode_permission+0x85/0x160 PGD 63681067 PUD 7ddbe067 PMD 0 Oops: 0000 [#1] PREEMPT CPU: 0 PID: 5634 Comm: ftrace-test-mki Not tainted 3.13.0-rc4-test-00033-gd2a6dde-dirty #20 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006 task: ffff880078375800 ti: ffff88007ddb0000 task.ti: ffff88007ddb0000 RIP: 0010:[] [] selinux_inode_permission+0x85/0x160 RSP: 0018:ffff88007ddb1c48 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000800000 RCX: ffff88006dd43840 RDX: 0000000000000001 RSI: 0000000000000081 RDI: ffff88006ee46000 RBP: ffff88007ddb1c88 R08: 0000000000000000 R09: ffff88007ddb1c54 R10: 6e6576652f6f6f66 R11: 0000000000000003 R12: 0000000000000000 R13: 0000000000000081 R14: ffff88006ee46000 R15: 0000000000000000 FS: 00007f217b5b6700(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M CR2: 0000000000000020 CR3: 000000006a0fe000 CR4: 00000000000007f0 Call Trace: security_inode_permission+0x1c/0x30 __inode_permission+0x41/0xa0 inode_permission+0x18/0x50 link_path_walk+0x66/0x920 path_openat+0xa6/0x6c0 do_filp_open+0x43/0xa0 do_sys_open+0x146/0x240 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b Code: 84 a1 00 00 00 81 e3 00 20 00 00 89 d8 83 c8 02 40 f6 c6 04 0f 45 d8 40 f6 c6 08 74 71 80 cf 02 49 8b 46 38 4c 8d 4d cc 45 31 c0 <0f> b7 50 20 8b 70 1c 48 8b 41 70 89 d9 8b 78 04 e8 36 cf ff ff RIP selinux_inode_permission+0x85/0x160 CR2: 0000000000000020 Investigating, I found that the inode->i_security was NULL, and the dereference of it caused the oops. in selinux_inode_permission(): isec = inode->i_security; rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); Note, the crash came from stressing the deletion and reading of debugfs files. I was not able to recreate this via normal files. But I'm not sure they are safe. It may just be that the race window is much harder to hit. What seems to have happened (and what I have traced), is the file is being opened at the same time the file or directory is being deleted. As the dentry and inode locks are not held during the path walk, nor is the inodes ref counts being incremented, there is nothing saving these structures from being discarded except for an rcu_read_lock(). The rcu_read_lock() protects against freeing of the inode, but it does not protect freeing of the inode_security_struct. Now if the freeing of the i_security happens with a call_rcu(), and the i_security field of the inode is not changed (it gets freed as the inode gets freed) then there will be no issue here. (Linus Torvalds suggested not setting the field to NULL such that we do not need to check if it is NULL in the permission check). Note, this is a hack, but it fixes the problem at hand. A real fix is to restructure the destroy_inode() to call all the destructor handlers from the RCU callback. But that is a major job to do, and requires a lot of work. For now, we just band-aid this bug with this fix (it works), and work on a more maintainable solution in the future. Link: http://lkml.kernel.org/r/20140109101932.0508dec7@gandalf.local.home Link: http://lkml.kernel.org/r/20140109182756.17abaaa8@gandalf.local.home Signed-off-by: Steven Rostedt Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute()

2014-01-08T17:42:12Z

commit c0828e50485932b7e019df377a6b0a8d1ebd3080 upstream. Due to difficulty in arriving at the proper security label for TCP SYN-ACK packets in selinux_ip_postroute(), we need to check packets while/before they are undergoing XFRM transforms instead of waiting until afterwards so that we can determine the correct security label. Reported-by: Janak Desai Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: look for IPsec labels on both inbound and outbound packets

2014-01-08T17:42:12Z

commit 817eff718dca4e54d5721211ddde0914428fbb7c upstream. Previously selinux_skb_peerlbl_sid() would only check for labeled IPsec security labels on inbound packets, this patch enables it to check both inbound and outbound traffic for labeled IPsec security labels. Reported-by: Janak Desai Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock()

2014-01-08T17:42:10Z

commit c0c1439541f5305b57a83d599af32b74182933fe upstream. selinux_setprocattr() does ptrace_parent(p) under task_lock(p), but task_struct->alloc_lock doesn't pin ->parent or ->ptrace, this looks confusing and triggers the "suspicious RCU usage" warning because ptrace_parent() does rcu_dereference_check(). And in theory this is wrong, spin_lock()->preempt_disable() doesn't necessarily imply rcu_read_lock() we need to access the ->parent. Reported-by: Evan McNabb Signed-off-by: Oleg Nesterov Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: fix broken peer recv check

2014-01-08T17:42:10Z

commit 46d01d63221c3508421dd72ff9c879f61053cffc upstream. Fix a broken networking check. Return an error if peer recv fails. If secmark is active and the packet recv succeeds the peer recv error is ignored. Signed-off-by: Chad Hanson Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute()

2013-12-20T15:34:20Z

commit 446b802437f285de68ffb8d6fac3c44c3cab5b04 upstream. In selinux_ip_postroute() we perform access checks based on the packet's security label. For locally generated traffic we get the packet's security label from the associated socket; this works in all cases except for TCP SYN-ACK packets. In the case of SYN-ACK packet's the correct security label is stored in the connection's request_sock, not the server's socket. Unfortunately, at the point in time when selinux_ip_postroute() is called we can't query the request_sock directly, we need to recreate the label using the same logic that originally labeled the associated request_sock. See the inline comments for more explanation. Reported-by: Janak Desai Tested-by: Janak Desai Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output()

2013-12-20T15:34:20Z

commit 47180068276a04ed31d24fe04c673138208b07a9 upstream. In selinux_ip_output() we always label packets based on the parent socket. While this approach works in almost all cases, it doesn't work in the case of TCP SYN-ACK packets when the correct label is not the label of the parent socket, but rather the label of the larval socket represented by the request_sock struct. Unfortunately, since the request_sock isn't queued on the parent socket until *after* the SYN-ACK packet is sent, we can't lookup the request_sock to determine the correct label for the packet; at this point in time the best we can do is simply pass/NF_ACCEPT the packet. It must be said that simply passing the packet without any explicit labeling action, while far from ideal, is not terrible as the SYN-ACK packet will inherit any IP option based labeling from the initial connection request so the label *should* be correct and all our access controls remain in place so we shouldn't have to worry about information leaks. Reported-by: Janak Desai Tested-by: Janak Desai Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: correct locking in selinux_netlbl_socket_connect)

2013-12-04T18:50:32Z

commit 42d64e1add3a1ce8a787116036163b8724362145 upstream. The SELinux/NetLabel glue code has a locking bug that affects systems with NetLabel enabled, see the kernel error message below. This patch corrects this problem by converting the bottom half socket lock to a more conventional, and correct for this call-path, lock_sock() call. =============================== [ INFO: suspicious RCU usage. ] 3.11.0-rc3+ #19 Not tainted ------------------------------- net/ipv4/cipso_ipv4.c:1928 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ping/731: #0: (slock-AF_INET/1){+.-...}, at: [...] selinux_netlbl_socket_connect #1: (rcu_read_lock){.+.+..}, at: [<...>] netlbl_conn_setattr stack backtrace: CPU: 1 PID: 731 Comm: ping Not tainted 3.11.0-rc3+ #19 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000001 ffff88006f659d28 ffffffff81726b6a ffff88003732c500 ffff88006f659d58 ffffffff810e4457 ffff88006b845a00 0000000000000000 000000000000000c ffff880075aa2f50 ffff88006f659d90 ffffffff8169bec7 Call Trace: [] dump_stack+0x54/0x74 [] lockdep_rcu_suspicious+0xe7/0x120 [] cipso_v4_sock_setattr+0x187/0x1a0 [] netlbl_conn_setattr+0x187/0x190 [] ? netlbl_conn_setattr+0x5/0x190 [] selinux_netlbl_socket_connect+0xae/0xc0 [] selinux_socket_connect+0x135/0x170 [] ? might_fault+0x57/0xb0 [] security_socket_connect+0x16/0x20 [] SYSC_connect+0x73/0x130 [] ? sysret_check+0x22/0x5d [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] SyS_connect+0xe/0x10 [] system_call_fastpath+0x16/0x1b Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

Revert "ima: policy for RAMFS"

2013-11-29T18:50:34Z

commit 08de59eb144d7c41351a467442f898d720f0f15f upstream. This reverts commit 4c2c392763a682354fac65b6a569adec4e4b5387. Everything in the initramfs should be measured and appraised, but until the initramfs has extended attribute support, at least measured. Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman