4.9-stable patches

added patches:
	keys-prevent-keyctl_read-on-negative-key.patch

diff --git a/queue-4.9/keys-prevent-keyctl_read-on-negative-key.patch b/queue-4.9/keys-prevent-keyctl_read-on-negative-key.patch
new file mode 100644 (file)
index 0000000..da311cd
--- /dev/null
+++ b/queue-4.9/keys-prevent-keyctl_read-on-negative-key.patch
@@ -0,0 +1,80 @@
+From 37863c43b2c6464f252862bf2e9768264e961678 Mon Sep 17 00:00:00 2001
+From: Eric Biggers <ebiggers@google.com>
+Date: Mon, 18 Sep 2017 11:37:23 -0700
+Subject: KEYS: prevent KEYCTL_READ on negative key
+
+From: Eric Biggers <ebiggers@google.com>
+
+commit 37863c43b2c6464f252862bf2e9768264e961678 upstream.
+
+Because keyctl_read_key() looks up the key with no permissions
+requested, it may find a negatively instantiated key.  If the key is
+also possessed, we went ahead and called ->read() on the key.  But the
+key payload will actually contain the ->reject_error rather than the
+normal payload.  Thus, the kernel oopses trying to read the
+user_key_payload from memory address (int)-ENOKEY = 0x00000000ffffff82.
+
+Fortunately the payload data is stored inline, so it shouldn't be
+possible to abuse this as an arbitrary memory read primitive...
+
+Reproducer:
+    keyctl new_session
+    keyctl request2 user desc '' @s
+    keyctl read $(keyctl show | awk '/user: desc/ {print $1}')
+
+It causes a crash like the following:
+     BUG: unable to handle kernel paging request at 00000000ffffff92
+     IP: user_read+0x33/0xa0
+     PGD 36a54067 P4D 36a54067 PUD 0
+     Oops: 0000 [#1] SMP
+     CPU: 0 PID: 211 Comm: keyctl Not tainted 4.14.0-rc1 #337
+     Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
+     task: ffff90aa3b74c3c0 task.stack: ffff9878c0478000
+     RIP: 0010:user_read+0x33/0xa0
+     RSP: 0018:ffff9878c047bee8 EFLAGS: 00010246
+     RAX: 0000000000000001 RBX: ffff90aa3d7da340 RCX: 0000000000000017
+     RDX: 0000000000000000 RSI: 00000000ffffff82 RDI: ffff90aa3d7da340
+     RBP: ffff9878c047bf00 R08: 00000024f95da94f R09: 0000000000000000
+     R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
+     R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
+     FS:  00007f58ece69740(0000) GS:ffff90aa3e200000(0000) knlGS:0000000000000000
+     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+     CR2: 00000000ffffff92 CR3: 0000000036adc001 CR4: 00000000003606f0
+     Call Trace:
+      keyctl_read_key+0xac/0xe0
+      SyS_keyctl+0x99/0x120
+      entry_SYSCALL_64_fastpath+0x1f/0xbe
+     RIP: 0033:0x7f58ec787bb9
+     RSP: 002b:00007ffc8d401678 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa
+     RAX: ffffffffffffffda RBX: 00007ffc8d402800 RCX: 00007f58ec787bb9
+     RDX: 0000000000000000 RSI: 00000000174a63ac RDI: 000000000000000b
+     RBP: 0000000000000004 R08: 00007ffc8d402809 R09: 0000000000000020
+     R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc8d402800
+     R13: 00007ffc8d4016e0 R14: 0000000000000000 R15: 0000000000000000
+     Code: e5 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb e8 a4 b4 ad ff 85 c0 74 09 80 3d b9 4c 96 00 00 74 43 48 8b b3 20 01 00 00 4d 85 ed <0f> b7 5e 10 74 29 4d 85 e4 74 24 4c 39 e3 4c 89 e2 4c 89 ef 48
+     RIP: user_read+0x33/0xa0 RSP: ffff9878c047bee8
+     CR2: 00000000ffffff92
+
+Fixes: 61ea0c0ba904 ("KEYS: Skip key state checks when checking for possession")
+Signed-off-by: Eric Biggers <ebiggers@google.com>
+Signed-off-by: David Howells <dhowells@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ security/keys/keyctl.c |    5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/security/keys/keyctl.c
++++ b/security/keys/keyctl.c
+@@ -766,6 +766,11 @@ long keyctl_read_key(key_serial_t keyid,
+ 
+       key = key_ref_to_ptr(key_ref);
+ 
++      if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
++              ret = -ENOKEY;
++              goto error2;
++      }
++
+       /* see if we can read it directly */
+       ret = key_permission(key_ref, KEY_NEED_READ);
+       if (ret == 0)

diff --git a/queue-4.9/series b/queue-4.9/series
index 939939e7243fc6c09e26cb16704183ab9e64c82a..4905a38cac1e6a78bd75fba45407732e04a1d6dd 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -21,3 +21,4 @@ security-keys-properly-zero-out-sensitive-key-material-in-big_key.patch
 security-keys-rewrite-all-of-big_key-crypto.patch
 keys-fix-writing-past-end-of-user-supplied-buffer-in-keyring_read.patch
 keys-prevent-creating-a-different-user-s-keyrings.patch
+keys-prevent-keyctl_read-on-negative-key.patch