[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ]
We have an upper bound on "maplevel" but forgot to check for negative
values.
Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]
This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".
Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit beb4ee6770a89646659e6a2178538d2b13e2654e upstream.
smk_write_relabel_self() frees memory from the task's credentials with
no locking, which can easily cause a use-after-free because multiple
tasks can share the same credentials structure.
Fix this by using prepare_creds() and commit_creds() to correctly modify
the task's credentials.
Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self":
#include <fcntl.h>
#include <pthread.h>
#include <unistd.h>
static void *thrproc(void *arg)
{
int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY);
for (;;) write(fd, "foo", 3);
}
int main()
{
pthread_t t;
pthread_create(&t, NULL, thrproc, NULL);
thrproc(NULL);
}
Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com
Fixes: 38416e53936e ("Smack: limited capability for changing process label")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 84e99e58e8d1e26f04c097f4266e431a33987f36 upstream. Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded. Suggested-by: Hillf Danton <hdanton@sina.com> Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c1a85a00ea66cb6f0bd0f14e47c28c2b0999799f ] This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton <mortonm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e5bfad3d7acc5702f32aafeb388362994f4d7bd0 upstream. inode_smack::smk_lock is taken during smack_d_instantiate(), which is called during a filesystem transaction when creating a file on ext4. Therefore to avoid a deadlock, all code that takes this lock must use GFP_NOFS, to prevent memory reclaim from waiting for the filesystem transaction to complete. Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3675f052b43ba51b99b85b073c7070e083f3e6fb upstream.
There is a logic bug in the current smack_bprm_set_creds():
If LSM_UNSAFE_PTRACE is set, but the ptrace state is deemed to be
acceptable (e.g. because the ptracer detached in the meantime), the other
->unsafe flags aren't checked. As far as I can tell, this means that
something like the following could work (but I haven't tested it):
- task A: create task B with fork()
- task B: set NO_NEW_PRIVS
- task B: install a seccomp filter that makes open() return 0 under some
conditions
- task B: replace fd 0 with a malicious library
- task A: attach to task B with PTRACE_ATTACH
- task B: execve() a file with an SMACK64EXEC extended attribute
- task A: while task B is still in the middle of execve(), exit (which
destroys the ptrace relationship)
Make sure that if any flags other than LSM_UNSAFE_PTRACE are set in
bprm->unsafe, we reject the execve().
Cc: stable@vger.kernel.org
Fixes: 5663884caab1 ("Smack: unify all ptrace accesses in the smack")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3f4287e7d98a2954f20bf96c567fdffcd2b63eb9 ]
In smack_socket_sock_rcv_skb(), there is an if statement
on line 3920 to check whether skb is NULL:
if (skb && skb->secmark != 0)
This check indicates skb can be NULL in some cases.
But on lines 3931 and 3932, skb is used:
ad.a.u.net->netif = skb->skb_iif;
ipv6_skb_to_auditdata(skb, &ad.a, NULL);
Thus, possible null-pointer dereferences may occur when skb is NULL.
To fix these possible bugs, an if statement is added to check skb.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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 <zmarkovic@sierrawireless.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dcb569cf6ac99ca899b8109c128b6ae52477a015 ] This fixes a pair of problems in the Smack ptrace checks related to checking capabilities. In both cases, as reported by Lukasz Pawelczyk, the raw capability calls are used rather than the Smack wrapper that check addition restrictions. In one case, as reported by Jann Horn, the wrong task is being checked for capabilities. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>