user/sven/linux.git/security, branch v4.19.32

security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock

2019-03-23T19:10:06Z

commit 3815a245b50124f0865415dcb606a034e97494d4 upstream. In the case when we're reusing a superblock, selinux_sb_clone_mnt_opts() fails to set set_kern_flags, with the result that nfs_clone_sb_security() incorrectly clears NFS_CAP_SECURITY_LABEL. The result is that if you mount the same NFS filesystem twice, NFS security labels are turned off, even if they would work fine if you mounted the filesystem only once. ("fixes" may be not exactly the right tag, it may be more like "fixed-other-cases-but-missed-this-one".) Cc: Scott Mayhew Cc: stable@vger.kernel.org Fixes: 0b4d3452b8b4 "security/selinux: allow security_sb_clone_mnt_opts..." Signed-off-by: J. Bruce Fields Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: add the missing walk_size + len check in selinux_sctp_bind_connect

2019-03-23T19:10:06Z

commit 292c997a1970f8d1e1dfa354ed770a22f7b5a434 upstream. As does in __sctp_connect(), when checking addrs in a while loop, after get the addr len according to sa_family, it's necessary to do the check walk_size + af->sockaddr_len > addrs_size to make sure it won't access an out-of-bounds addr. The same thing is needed in selinux_sctp_bind_connect(), otherwise an out-of-bounds issue can be triggered: [14548.772313] BUG: KASAN: slab-out-of-bounds in selinux_sctp_bind_connect+0x1aa/0x1f0 [14548.927083] Call Trace: [14548.938072] dump_stack+0x9a/0xe9 [14548.953015] print_address_description+0x65/0x22e [14548.996524] kasan_report.cold.6+0x92/0x1a6 [14549.015335] selinux_sctp_bind_connect+0x1aa/0x1f0 [14549.036947] security_sctp_bind_connect+0x58/0x90 [14549.058142] __sctp_setsockopt_connectx+0x5a/0x150 [sctp] [14549.081650] sctp_setsockopt.part.24+0x1322/0x3ce0 [sctp] Cc: stable@vger.kernel.org Fixes: d452930fd3b9 ("selinux: Add SCTP support") Reported-by: Chunyu Hu Signed-off-by: Xin Long Reviewed-by: Marcelo Ricardo Leitner Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

keys: Fix dependency loop between construction record and auth key

2019-03-23T19:09:48Z

[ Upstream commit 822ad64d7e46a8e2c8b8a796738d7b657cbb146d ] In the request_key() upcall mechanism there's a dependency loop by which if a key type driver overrides the ->request_key hook and the userspace side manages to lose the authorisation key, the auth key and the internal construction record (struct key_construction) can keep each other pinned. Fix this by the following changes: (1) Killing off the construction record and using the auth key instead. (2) Including the operation name in the auth key payload and making the payload available outside of security/keys/. (3) The ->request_key hook is given the authkey instead of the cons record and operation name. Changes (2) and (3) allow the auth key to naturally be cleaned up if the keyring it is in is destroyed or cleared or the auth key is unlinked. Fixes: 7ee02a316600 ("keys: Fix dependency loop between construction record and auth key") Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Sasha Levin

missing barriers in some of unix_sock ->addr and ->path accesses

2019-03-19T12:12:41Z

[ Upstream commit ae3b564179bfd06f32d051b9e5d72ce4b2a07c37 ] Several u->addr and u->path users are not holding any locks in common with unix_bind(). unix_state_lock() is useless for those purposes. u->addr is assign-once and *(u->addr) is fully set up by the time we set u->addr (all under unix_table_lock). u->path is also set in the same critical area, also before setting u->addr, and any unix_sock with ->path filled will have non-NULL ->addr. So setting ->addr with smp_store_release() is all we need for those "lockless" users - just have them fetch ->addr with smp_load_acquire() and don't even bother looking at ->path if they see NULL ->addr. Users of ->addr and ->path fall into several classes now: 1) ones that do smp_load_acquire(u->addr) and access *(u->addr) and u->path only if smp_load_acquire() has returned non-NULL. 2) places holding unix_table_lock. These are guaranteed that *(u->addr) is seen fully initialized. If unix_sock is in one of the "bound" chains, so's ->path. 3) unix_sock_destructor() using ->addr is safe. All places that set u->addr are guaranteed to have seen all stores *(u->addr) while holding a reference to u and unix_sock_destructor() is called when (atomic) refcount hits zero. 4) unix_release_sock() using ->path is safe. unix_bind() is serialized wrt unix_release() (normally - by struct file refcount), and for the instances that had ->path set by unix_bind() unix_release_sock() comes from unix_release(), so they are fine. Instances that had it set in unix_stream_connect() either end up attached to a socket (in unix_accept()), in which case the call chain to unix_release_sock() and serialization are the same as in the previous case, or they never get accept'ed and unix_release_sock() is called when the listener is shut down and its queue gets purged. In that case the listener's queue lock provides the barriers needed - unix_stream_connect() shoves our unix_sock into listener's queue under that lock right after having set ->path and eventual unix_release_sock() caller picks them from that queue under the same lock right before calling unix_release_sock(). 5) unix_find_other() use of ->path is pointless, but safe - it happens with successful lookup by (abstract) name, so ->path.dentry is guaranteed to be NULL there. earlier-variant-reviewed-by: "Paul E. McKenney" Signed-off-by: Al Viro Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

apparmor: Fix aa_label_build() error handling for failed merges

2019-03-13T21:02:32Z

[ Upstream commit d6d478aee003e19ef90321176552a8ad2929a47f ] aa_label_merge() can return NULL for memory allocations failures make sure to handle and set the correct error in this case. Reported-by: Peng Hao Signed-off-by: John Johansen Signed-off-by: Sasha Levin

KEYS: always initialize keyring_index_key::desc_len

2019-02-27T09:09:00Z

commit ede0fa98a900e657d1fcd80b50920efc896c1a4c upstream. syzbot hit the 'BUG_ON(index_key->desc_len == 0);' in __key_link_begin() called from construct_alloc_key() during sys_request_key(), because the length of the key description was never calculated. The problem is that we rely on ->desc_len being initialized by search_process_keyrings(), specifically by search_nested_keyrings(). But, if the process isn't subscribed to any keyrings that never happens. Fix it by always initializing keyring_index_key::desc_len as soon as the description is set, like we already do in some places. The following program reproduces the BUG_ON() when it's run as root and no session keyring has been installed. If it doesn't work, try removing pam_keyinit.so from /etc/pam.d/login and rebooting. #include #include #include int main(void) { int id = add_key("keyring", "syz", NULL, 0, KEY_SPEC_USER_KEYRING); keyctl_setperm(id, KEY_OTH_WRITE); setreuid(5000, 5000); request_key("user", "desc", "", id); } Reported-by: syzbot+ec24e95ea483de0a24da@syzkaller.appspotmail.com Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Signed-off-by: Eric Biggers Signed-off-by: David Howells Cc: stable@vger.kernel.org Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman

KEYS: allow reaching the keys quotas exactly

2019-02-27T09:08:50Z

commit a08bf91ce28ed3ae7b6fef35d843fef8dc8c2cd9 upstream. If the sysctl 'kernel.keys.maxkeys' is set to some number n, then actually users can only add up to 'n - 1' keys. Likewise for 'kernel.keys.maxbytes' and the root_* versions of these sysctls. But these sysctls are apparently supposed to be *maximums*, as per their names and all documentation I could find -- the keyrings(7) man page, Documentation/security/keys/core.rst, and all the mentions of EDQUOT meaning that the key quota was *exceeded* (as opposed to reached). Thus, fix the code to allow reaching the quotas exactly. Fixes: 0b77f5bfb45c ("keys: make the keyring quotas controllable through /proc/sys") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman

smack: fix access permissions for keyring

2019-02-12T18:47:05Z

[ Upstream commit 5b841bfab695e3b8ae793172a9ff7990f99cc3e2 ] Function smack_key_permission() only issues smack requests for the following operations: - KEY_NEED_READ (issues MAY_READ) - KEY_NEED_WRITE (issues MAY_WRITE) - KEY_NEED_LINK (issues MAY_WRITE) - KEY_NEED_SETATTR (issues MAY_WRITE) A blank smack request is issued in all other cases, resulting in smack access being granted if there is any rule defined between subject and object, or denied with -EACCES otherwise. Request MAY_READ access for KEY_NEED_SEARCH and KEY_NEED_VIEW. Fix the logic in the unlikely case when both MAY_READ and MAY_WRITE are needed. Validate access permission field for valid contents. Signed-off-by: Zoran Markovic Signed-off-by: Casey Schaufler Cc: Casey Schaufler Cc: James Morris Cc: "Serge E. Hallyn" Signed-off-by: Sasha Levin

selinux: always allow mounting submounts

2019-01-26T08:32:36Z

[ Upstream commit 2cbdcb882f97a45f7475c67ac6257bbc16277dfe ] If a superblock has the MS_SUBMOUNT flag set, we should always allow mounting it. These mounts are done automatically by the kernel either as part of mounting some parent mount (e.g. debugfs always mounts tracefs under "tracing" for compatibility) or they are mounted automatically as needed on subdirectory accesses (e.g. NFS crossmnt mounts). Since such automounts are either an implicit consequence of the parent mount (which is already checked) or they can happen during regular accesses (where it doesn't make sense to check against the current task's context), the mount permission check should be skipped for them. Without this patch, attempts to access contents of an automounted directory can cause unexpected SELinux denials. In the current kernel tree, the MS_SUBMOUNT flag is set only via vfs_submount(), which is called only from the following places: - AFS, when automounting special "symlinks" referencing other cells - CIFS, when automounting "referrals" - NFS, when automounting subtrees - debugfs, when automounting tracefs In all cases the submounts are meant to be transparent to the user and it makes sense that if mounting the master is allowed, then so should be the automounts. Note that CAP_SYS_ADMIN capability checking is already skipped for (SB_KERNMOUNT|SB_SUBMOUNT) in: - sget_userns() in fs/super.c: if (!(flags & (SB_KERNMOUNT|SB_SUBMOUNT)) && !(type->fs_flags & FS_USERNS_MOUNT) && !capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); - sget() in fs/super.c: /* Ensure the requestor has permissions over the target filesystem */ if (!(flags & (SB_KERNMOUNT|SB_SUBMOUNT)) && !ns_capable(user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); Verified internally on patched RHEL 7.6 with a reproducer using NFS+httpd and selinux-tesuite. Fixes: 93faccbbfa95 ("fs: Better permission checking for submounts") Signed-off-by: Ondrej Mosnacek Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

selinux: fix GPF on invalid policy

2019-01-22T20:40:35Z

commit 5b0e7310a2a33c06edc7eb81ffc521af9b2c5610 upstream. levdatum->level can be NULL if we encounter an error while loading the policy during sens_read prior to initializing it. Make sure sens_destroy handles that case correctly. Reported-by: syzbot+6664500f0f18f07a5c0e@syzkaller.appspotmail.com Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman