kernel/linux.git/security, branch v5.2.20

smack: use GFP_NOFS while holding inode_smack::smk_lock

2019-10-07T16:59:40+00:00

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 Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

Smack: Don't ignore other bprm->unsafe flags if LSM_UNSAFE_PTRACE is set

2019-10-07T16:59:39+00:00

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 Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb()

2019-10-07T16:59:33+00:00

[ 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 Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

selinux: fix residual uses of current_security() for the SELinux blob

2019-10-07T16:59:31+00:00

[ Upstream commit 169ce0c081cd85f78388bb6c1638c1ad7b81bde7 ] We need to use selinux_cred() to fetch the SELinux cred blob instead of directly using current->security or current_security(). There were a couple of lingering uses of current_security() in the SELinux code that were apparently missed during the earlier conversions. IIUC, this would only manifest as a bug if multiple security modules including SELinux are enabled and SELinux is not first in the lsm order. After this change, there appear to be no other users of current_security() in-tree; perhaps we should remove it altogether. Fixes: bbd3662a8348 ("Infrastructure management of the cred security blob") Signed-off-by: Stephen Smalley Acked-by: Casey Schaufler Reviewed-by: James Morris Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

KEYS: trusted: correctly initialize digests and fix locking issue

2019-10-05T11:14:11+00:00

commit 9f75c82246313d4c2a6bc77e947b45655b3b5ad5 upstream. Commit 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()") modifies tpm_pcr_extend() to accept a digest for each PCR bank. After modification, tpm_pcr_extend() expects that digests are passed in the same order as the algorithms set in chip->allocated_banks. This patch fixes two issues introduced in the last iterations of the patch set: missing initialization of the TPM algorithm ID in the tpm_digest structures passed to tpm_pcr_extend() by the trusted key module, and unreleased locks in the TPM driver due to returning from tpm_pcr_extend() without calling tpm_put_ops(). Cc: stable@vger.kernel.org Fixes: 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()") Signed-off-by: Roberto Sassu Suggested-by: Jarkko Sakkinen Reviewed-by: Jerry Snitselaar Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman

keys: Fix missing null pointer check in request_key_auth_describe()

2019-09-21T05:18:49+00:00

[ Upstream commit d41a3effbb53b1bcea41e328d16a4d046a508381 ] If a request_key authentication token key gets revoked, there's a window in which request_key_auth_describe() can see it with a NULL payload - but it makes no check for this and something like the following oops may occur: BUG: Kernel NULL pointer dereference at 0x00000038 Faulting instruction address: 0xc0000000004ddf30 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [...] request_key_auth_describe+0x90/0xd0 LR [...] request_key_auth_describe+0x54/0xd0 Call Trace: [...] request_key_auth_describe+0x54/0xd0 (unreliable) [...] proc_keys_show+0x308/0x4c0 [...] seq_read+0x3d0/0x540 [...] proc_reg_read+0x90/0x110 [...] __vfs_read+0x3c/0x70 [...] vfs_read+0xb4/0x1b0 [...] ksys_read+0x7c/0x130 [...] system_call+0x5c/0x70 Fix this by checking for a NULL pointer when describing such a key. Also make the read routine check for a NULL pointer to be on the safe side. [DH: Modified to not take already-held rcu lock and modified to also check in the read routine] Fixes: 04c567d9313e ("[PATCH] Keys: Fix race between two instantiators of a key") Reported-by: Sachin Sant Signed-off-by: Hillf Danton Signed-off-by: David Howells Tested-by: Sachin Sant Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

KEYS: trusted: allow module init if TPM is inactive or deactivated

2019-08-25T14:10:20+00:00

commit 2d6c25215ab26bb009de3575faab7b685f138e92 upstream. Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a TPM") allows the trusted module to be loaded even if a TPM is not found, to avoid module dependency problems. However, trusted module initialization can still fail if the TPM is inactive or deactivated. tpm_get_random() returns an error. This patch removes the call to tpm_get_random() and instead extends the PCR specified by the user with zeros. The security of this alternative is equivalent to the previous one, as either option prevents with a PCR update unsealing and misuse of sealed data by a user space process. Even if a PCR is extended with zeros, instead of random data, it is still computationally infeasible to find a value as input for a new PCR extend operation, to obtain again the PCR value that would allow unsealing. Cc: stable@vger.kernel.org Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...") Signed-off-by: Roberto Sassu Reviewed-by: Tyler Hicks Suggested-by: Mimi Zohar Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman

selinux: fix memory leak in policydb_init()

2019-08-06T17:08:17+00:00

commit 45385237f65aeee73641f1ef737d7273905a233f upstream. Since roles_init() adds some entries to the role hash table, we need to destroy also its keys/values on error, otherwise we get a memory leak in the error path. Cc: Reported-by: syzbot+fee3a14d4cdf92646287@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

structleak: disable STRUCTLEAK_BYREF in combination with KASAN_STACK

2019-07-31T05:25:02+00:00

commit 173e6ee21e2b3f477f07548a79c43b8d9cfbb37d upstream. The combination of KASAN_STACK and GCC_PLUGIN_STRUCTLEAK_BYREF leads to much larger kernel stack usage, as seen from the warnings about functions that now exceed the 2048 byte limit: drivers/media/i2c/tvp5150.c:253:1: error: the frame size of 3936 bytes is larger than 2048 bytes drivers/media/tuners/r820t.c:1327:1: error: the frame size of 2816 bytes is larger than 2048 bytes drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16552:1: error: the frame size of 3144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] fs/ocfs2/aops.c:1892:1: error: the frame size of 2088 bytes is larger than 2048 bytes fs/ocfs2/dlm/dlmrecovery.c:737:1: error: the frame size of 2088 bytes is larger than 2048 bytes fs/ocfs2/namei.c:1677:1: error: the frame size of 2584 bytes is larger than 2048 bytes fs/ocfs2/super.c:1186:1: error: the frame size of 2640 bytes is larger than 2048 bytes fs/ocfs2/xattr.c:3678:1: error: the frame size of 2176 bytes is larger than 2048 bytes net/bluetooth/l2cap_core.c:7056:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] net/bluetooth/l2cap_core.c: In function 'l2cap_recv_frame': net/bridge/br_netlink.c:1505:1: error: the frame size of 2448 bytes is larger than 2048 bytes net/ieee802154/nl802154.c:548:1: error: the frame size of 2232 bytes is larger than 2048 bytes net/wireless/nl80211.c:1726:1: error: the frame size of 2224 bytes is larger than 2048 bytes net/wireless/nl80211.c:2357:1: error: the frame size of 4584 bytes is larger than 2048 bytes net/wireless/nl80211.c:5108:1: error: the frame size of 2760 bytes is larger than 2048 bytes net/wireless/nl80211.c:6472:1: error: the frame size of 2112 bytes is larger than 2048 bytes The structleak plugin was previously disabled for CONFIG_COMPILE_TEST, but meant we missed some bugs, so this time we should address them. The frame size warnings are distracting, and risking a kernel stack overflow is generally not beneficial to performance, so it may be best to disallow that particular combination. This can be done by turning off either one. I picked the dependency in GCC_PLUGIN_STRUCTLEAK_BYREF and GCC_PLUGIN_STRUCTLEAK_BYREF_ALL, as this option is designed to make uninitialized stack usage less harmful when enabled on its own, but it also prevents KASAN from detecting those cases in which it was in fact needed. KASAN_STACK is currently implied by KASAN on gcc, but could be made a user selectable option if we want to allow combining (non-stack) KASAN with GCC_PLUGIN_STRUCTLEAK_BYREF. Note that it would be possible to specifically address the files that print the warning, but presumably the overall stack usage is still significantly higher than in other configurations, so this would not address the full problem. I could not test this with CONFIG_INIT_STACK_ALL, which may or may not suffer from a similar problem. Fixes: 81a56f6dcd20 ("gcc-plugins: structleak: Generalize to all variable types") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20190722114134.3123901-1-arnd@arndb.de Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

selinux: check sidtab limit before adding a new entry

2019-07-31T05:24:58+00:00

commit acbc372e6109c803cbee4733769d02008381740f upstream. We need to error out when trying to add an entry above SIDTAB_MAX in sidtab_reverse_lookup() to avoid overflow on the odd chance that this happens. Cc: stable@vger.kernel.org Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") Signed-off-by: Ondrej Mosnacek Reviewed-by: Kees Cook Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman