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-rw-r--r--KEYS-don-t-let-add_key-update-an-uninstantiated-key.patch130
1 files changed, 0 insertions, 130 deletions
diff --git a/KEYS-don-t-let-add_key-update-an-uninstantiated-key.patch b/KEYS-don-t-let-add_key-update-an-uninstantiated-key.patch
deleted file mode 100644
index af7478ee5..000000000
--- a/KEYS-don-t-let-add_key-update-an-uninstantiated-key.patch
+++ /dev/null
@@ -1,130 +0,0 @@
-From 7289bfaee2a42bdb56eecab0625907c045d080ba Mon Sep 17 00:00:00 2001
-From: Eric Biggers <ebiggers@google.com>
-Date: Wed, 27 Sep 2017 12:50:41 -0700
-Subject: [PATCH] KEYS: don't let add_key() update an uninstantiated key
-
-Currently, add_key() will, when passed a key that already exists, call
-the key's ->update() method. But this is heavily broken in the case
-where the key is uninstantiated because it doesn't call
-__key_instantiate_and_link(). Consequently, it doesn't do most of the
-things that are supposed to happen when the key is instantiated, such as
-setting KEY_FLAG_INSTANTIATED, clearing KEY_FLAG_USER_CONSTRUCT and
-awakening tasks waiting on it, and incrementing key->user->nikeys.
-
-It also never takes key_construction_mutex, which means that
-->instantiate() can run concurrently with ->update() on the same key.
-In the case of the "user" and "logon" key types this causes a memory
-leak, at best. Maybe even worse, the ->update() methods of the
-"encrypted" and "trusted" key types actually just dereference a NULL
-pointer when passed an uninstantiated key.
-
-Therefore, change find_key_to_update() to return NULL if the found key
-is uninstantiated, so that add_key() replaces the key rather than
-instantiating it. This seems to be better than fixing __key_update() to
-call __key_instantiate_and_link(), since given all the bugs noted above
-as well as that the existing behavior was undocumented and
-keyctl_instantiate() is supposed to be used instead, I doubt anyone was
-relying on the existing behavior.
-
-This patch only affects *uninstantiated* keys. For now we still allow a
-negatively instantiated key to be updated (thereby positively
-instantiating it), although that's broken too (the next patch fixes it)
-and I'm not sure that anyone actually uses that functionality either.
-
-Here is a simple reproducer for the bug using the "encrypted" key type
-(requires CONFIG_ENCRYPTED_KEYS=y), though as noted above the bug
-pertained to more than just the "encrypted" key type:
-
- #include <stdlib.h>
- #include <unistd.h>
- #include <keyutils.h>
-
- int main(void)
- {
- int ringid = keyctl_join_session_keyring(NULL);
-
- if (fork()) {
- for (;;) {
- const char payload[] = "update user:foo 32";
-
- usleep(rand() % 10000);
- add_key("encrypted", "desc", payload, sizeof(payload), ringid);
- keyctl_clear(ringid);
- }
- } else {
- for (;;)
- request_key("encrypted", "desc", "callout_info", ringid);
- }
- }
-
-It causes:
-
- BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
- IP: encrypted_update+0xb0/0x170
- PGD 7a178067 P4D 7a178067 PUD 77269067 PMD 0
- PREEMPT SMP
- CPU: 0 PID: 340 Comm: reproduce Tainted: G D 4.14.0-rc1-00025-g428490e38b2e #796
- Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
- task: ffff8a467a39a340 task.stack: ffffb15c40770000
- RIP: 0010:encrypted_update+0xb0/0x170
- RSP: 0018:ffffb15c40773de8 EFLAGS: 00010246
- RAX: 0000000000000000 RBX: ffff8a467a275b00 RCX: 0000000000000000
- RDX: 0000000000000005 RSI: ffff8a467a275b14 RDI: ffffffffb742f303
- RBP: ffffb15c40773e20 R08: 0000000000000000 R09: ffff8a467a275b17
- R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000
- R13: 0000000000000000 R14: ffff8a4677057180 R15: ffff8a467a275b0f
- FS: 00007f5d7fb08700(0000) GS:ffff8a467f200000(0000) knlGS:0000000000000000
- CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
- CR2: 0000000000000018 CR3: 0000000077262005 CR4: 00000000001606f0
- Call Trace:
- key_create_or_update+0x2bc/0x460
- SyS_add_key+0x10c/0x1d0
- entry_SYSCALL_64_fastpath+0x1f/0xbe
- RIP: 0033:0x7f5d7f211259
- RSP: 002b:00007ffed03904c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
- RAX: ffffffffffffffda RBX: 000000003b2a7955 RCX: 00007f5d7f211259
- RDX: 00000000004009e4 RSI: 00000000004009ff RDI: 0000000000400a04
- RBP: 0000000068db8bad R08: 000000003b2a7955 R09: 0000000000000004
- R10: 000000000000001a R11: 0000000000000246 R12: 0000000000400868
- R13: 00007ffed03905d0 R14: 0000000000000000 R15: 0000000000000000
- Code: 77 28 e8 64 34 1f 00 45 31 c0 31 c9 48 8d 55 c8 48 89 df 48 8d 75 d0 e8 ff f9 ff ff 85 c0 41 89 c4 0f 88 84 00 00 00 4c 8b 7d c8 <49> 8b 75 18 4c 89 ff e8 24 f8 ff ff 85 c0 41 89 c4 78 6d 49 8b
- RIP: encrypted_update+0xb0/0x170 RSP: ffffb15c40773de8
- CR2: 0000000000000018
-
-Cc: <stable@vger.kernel.org> [v2.6.12+]
-Signed-off-by: Eric Biggers <ebiggers@google.com>
----
- security/keys/keyring.c | 10 ++++++----
- 1 file changed, 6 insertions(+), 4 deletions(-)
-
-diff --git a/security/keys/keyring.c b/security/keys/keyring.c
-index 4fa82a8a9c0e..129a4175760b 100644
---- a/security/keys/keyring.c
-+++ b/security/keys/keyring.c
-@@ -1056,8 +1056,8 @@ EXPORT_SYMBOL(keyring_restrict);
- * caller must also hold a lock on the keyring semaphore.
- *
- * Returns a pointer to the found key with usage count incremented if
-- * successful and returns NULL if not found. Revoked and invalidated keys are
-- * skipped over.
-+ * successful and returns NULL if not found. Revoked, invalidated, and
-+ * uninstantiated keys are skipped over. (But negative keys are not!)
- *
- * If successful, the possession indicator is propagated from the keyring ref
- * to the returned key reference.
-@@ -1084,8 +1084,10 @@ key_ref_t find_key_to_update(key_ref_t keyring_ref,
-
- found:
- key = keyring_ptr_to_key(object);
-- if (key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-- (1 << KEY_FLAG_REVOKED))) {
-+ if ((key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-+ (1 << KEY_FLAG_REVOKED) |
-+ (1 << KEY_FLAG_INSTANTIATED))) !=
-+ (1 << KEY_FLAG_INSTANTIATED)) {
- kleave(" = NULL [x]");
- return NULL;
- }
---
-2.13.6
-