kernel/linux.git/security, branch v4.5.3

tpm: fix checks for policy digest existence in tpm2_seal_trusted()

2016-05-04T21:49:15+00:00

commit f3c82ade7c59303167d56b0be3e0707751fc45e2 upstream. In my original patch sealing with policy was done with dynamically allocated buffer that I changed later into an array so the checks in tpm2-cmd.c became invalid. This patch fixes the issue. Fixes: 5beb0c435bdd ("keys, trusted: seal with a TPM2 authorization policy") Reported-by: Dan Carpenter Signed-off-by: Jarkko Sakkinen Acked-by: Peter Huewe Signed-off-by: Greg Kroah-Hartman

Merge branch 'stable-4.5' of git://git.infradead.org/users/pcmoore/selinux into for-linus

2016-02-26T08:32:16+00:00

selinux: Don't sleep inside inode_getsecid hook

2016-02-19T21:29:19+00:00

The inode_getsecid hook is called from contexts in which sleeping is not allowed, so we cannot revalidate inode security labels from there. Use the non-validating version of inode_security() instead. Reported-by: Benjamin Coddington Signed-off-by: Andreas Gruenbacher Acked-by: Stephen Smalley Signed-off-by: Paul Moore

EVM: Use crypto_memneq() for digest comparisons

2016-02-12T07:36:47+00:00

This patch fixes vulnerability CVE-2016-2085. The problem exists because the vm_verify_hmac() function includes a use of memcmp(). Unfortunately, this allows timing side channel attacks; specifically a MAC forgery complexity drop from 2^128 to 2^12. This patch changes the memcmp() to the cryptographically safe crypto_memneq(). Reported-by: Xiaofei Rex Guo Signed-off-by: Ryan Ware Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar Signed-off-by: James Morris

selinux: nlmsgtab: add SOCK_DESTROY to the netlink mapping tables

2016-02-09T09:55:05+00:00

Without this, using SOCK_DESTROY in enforcing mode results in: SELinux: unrecognized netlink message type=21 for sclass=32 Signed-off-by: Lorenzo Colitti Signed-off-by: David S. Miller

KEYS: Only apply KEY_FLAG_KEEP to a key if a parent keyring has it set

2016-01-27T23:48:40+00:00

KEY_FLAG_KEEP should only be applied to a key if the keyring it is being linked into has KEY_FLAG_KEEP set. To this end, partially revert the following patch: commit 1d6d167c2efcfe9539d9cffb1a1be9c92e39c2c0 Author: Mimi Zohar Date: Thu Jan 7 07:46:36 2016 -0500 KEYS: refcount bug fix to undo the change that made it unconditional (Mimi got it right the first time). Without undoing this change, it becomes impossible to delete, revoke or invalidate keys added to keyrings through __key_instantiate_and_link() where the keyring has itself been linked to. To test this, run the following command sequence: keyctl newring foo @s keyctl add user a a %:foo keyctl unlink %user:a %:foo keyctl clear %:foo With the commit mentioned above the third and fourth commands fail with EPERM when they should succeed. Reported-by: Stephen Gallager Signed-off-by: David Howells Acked-by: Mimi Zohar cc: Mimi Zohar cc: keyrings@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: James Morris

wrappers for ->i_mutex access

2016-01-22T23:04:28+00:00

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro

ptrace: use fsuid, fsgid, effective creds for fs access checks

2016-01-21T01:09:18+00:00

By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn Acked-by: Kees Cook Cc: Casey Schaufler Cc: Oleg Nesterov Cc: Ingo Molnar Cc: James Morris Cc: "Serge E. Hallyn" Cc: Andy Shevchenko Cc: Andy Lutomirski Cc: Al Viro Cc: "Eric W. Biederman" Cc: Willy Tarreau Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

security: let security modules use PTRACE_MODE_* with bitmasks

2016-01-21T01:09:18+00:00

It looks like smack and yama weren't aware that the ptrace mode can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch, all modes have flags ORed into them. Signed-off-by: Jann Horn Acked-by: Kees Cook Acked-by: Casey Schaufler Cc: Oleg Nesterov Cc: Ingo Molnar Cc: James Morris Cc: "Serge E. Hallyn" Cc: Andy Shevchenko Cc: Andy Lutomirski Cc: Al Viro Cc: "Eric W. Biederman" Cc: Willy Tarreau Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

KEYS: Fix keyring ref leak in join_session_keyring()

2016-01-19T23:50:48+00:00

This fixes CVE-2016-0728. If a thread is asked to join as a session keyring the keyring that's already set as its session, we leak a keyring reference. This can be tested with the following program: #include #include #include #include int main(int argc, const char *argv[]) { int i = 0; key_serial_t serial; serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING, "leaked-keyring"); if (serial < 0) { perror("keyctl"); return -1; } if (keyctl(KEYCTL_SETPERM, serial, KEY_POS_ALL | KEY_USR_ALL) < 0) { perror("keyctl"); return -1; } for (i = 0; i < 100; i++) { serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING, "leaked-keyring"); if (serial < 0) { perror("keyctl"); return -1; } } return 0; } If, after the program has run, there something like the following line in /proc/keys: 3f3d898f I--Q--- 100 perm 3f3f0000 0 0 keyring leaked-keyring: empty with a usage count of 100 * the number of times the program has been run, then the kernel is malfunctioning. If leaked-keyring has zero usages or has been garbage collected, then the problem is fixed. Reported-by: Yevgeny Pats Signed-off-by: David Howells Acked-by: Don Zickus Acked-by: Prarit Bhargava Acked-by: Jarod Wilson Signed-off-by: James Morris