From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Dmitry Vyukov <dvyukov@google.com>,
David Howells <dhowells@redhat.com>
Subject: [PATCH 4.1 41/43] KEYS: Fix crash when attempt to garbage collect an uninstantiated keyring
Date: Wed, 20 Jan 2016 15:10:48 -0800 [thread overview]
Message-ID: <20160120215932.995943600@linuxfoundation.org> (raw)
In-Reply-To: <20160120215926.787430744@linuxfoundation.org>
4.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells <dhowells@redhat.com>
commit f05819df10d7b09f6d1eb6f8534a8f68e5a4fe61 upstream.
The following sequence of commands:
i=`keyctl add user a a @s`
keyctl request2 keyring foo bar @t
keyctl unlink $i @s
tries to invoke an upcall to instantiate a keyring if one doesn't already
exist by that name within the user's keyring set. However, if the upcall
fails, the code sets keyring->type_data.reject_error to -ENOKEY or some
other error code. When the key is garbage collected, the key destroy
function is called unconditionally and keyring_destroy() uses list_empty()
on keyring->type_data.link - which is in a union with reject_error.
Subsequently, the kernel tries to unlink the keyring from the keyring names
list - which oopses like this:
BUG: unable to handle kernel paging request at 00000000ffffff8a
IP: [<ffffffff8126e051>] keyring_destroy+0x3d/0x88
...
Workqueue: events key_garbage_collector
...
RIP: 0010:[<ffffffff8126e051>] keyring_destroy+0x3d/0x88
RSP: 0018:ffff88003e2f3d30 EFLAGS: 00010203
RAX: 00000000ffffff82 RBX: ffff88003bf1a900 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000003bfc6901 RDI: ffffffff81a73a40
RBP: ffff88003e2f3d38 R08: 0000000000000152 R09: 0000000000000000
R10: ffff88003e2f3c18 R11: 000000000000865b R12: ffff88003bf1a900
R13: 0000000000000000 R14: ffff88003bf1a908 R15: ffff88003e2f4000
...
CR2: 00000000ffffff8a CR3: 000000003e3ec000 CR4: 00000000000006f0
...
Call Trace:
[<ffffffff8126c756>] key_gc_unused_keys.constprop.1+0x5d/0x10f
[<ffffffff8126ca71>] key_garbage_collector+0x1fa/0x351
[<ffffffff8105ec9b>] process_one_work+0x28e/0x547
[<ffffffff8105fd17>] worker_thread+0x26e/0x361
[<ffffffff8105faa9>] ? rescuer_thread+0x2a8/0x2a8
[<ffffffff810648ad>] kthread+0xf3/0xfb
[<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
[<ffffffff815f2ccf>] ret_from_fork+0x3f/0x70
[<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
Note the value in RAX. This is a 32-bit representation of -ENOKEY.
The solution is to only call ->destroy() if the key was successfully
instantiated.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
security/keys/gc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -134,8 +134,10 @@ static noinline void key_gc_unused_keys(
kdebug("- %u", key->serial);
key_check(key);
- /* Throw away the key data */
- if (key->type->destroy)
+ /* Throw away the key data if the key is instantiated */
+ if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
+ !test_bit(KEY_FLAG_NEGATIVE, &key->flags) &&
+ key->type->destroy)
key->type->destroy(key);
security_key_free(key);
next prev parent reply other threads:[~2016-01-20 23:11 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 23:10 [PATCH 4.1 00/43] 4.1.16-stable review Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 01/43] tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0 Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 02/43] toshiba_acpi: Initialize hotkey_event_type variable Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 03/43] USB: cdc_acm: Ignore Infineon Flash Loader utility Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 04/43] USB: serial: Another Infineon flash loader USB ID Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 05/43] usb-storage: Fix scsi-sd failure "Invalid field in cdb" for USB adapter JMicron Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 06/43] USB: cp210x: Remove CP2110 ID from compatibility list Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 07/43] USB: add quirk for devices with broken LPM Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 08/43] USB: whci-hcd: add check for dma mapping error Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 09/43] usb: gadget: pxa27x: fix suspend callback Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 10/43] usb: musb: USB_TI_CPPI41_DMA requires dmaengine support Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 11/43] usb: core : hub: Fix BOS NULL pointer kernel panic Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 12/43] usb: Use the USB_SS_MULT() macro to decode burst multiplier for log message Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 13/43] pppoe: fix memory corruption in padt work structure Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 14/43] gre6: allow to update all parameters via rtnl Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 15/43] atl1c: Improve driver not to do order 4 GFP_ATOMIC allocation Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 17/43] vxlan: fix incorrect RCO bit in VXLAN header Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 18/43] sctp: use the same clock as if sock source timestamps were on Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 19/43] sctp: update the netstamp_needed counter when copying sockets Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 20/43] sctp: also copy sk_tsflags when copying the socket Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 21/43] net: qca_spi: fix transmit queue timeout handling Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 22/43] r8152: fix lockup when runtime PM is enabled Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 23/43] ipv6: sctp: clone options to avoid use after free Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 25/43] sh_eth: fix kernel oops in skb_put() Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 26/43] net: fix IP early demux races Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 27/43] pptp: verify sockaddr_len in pptp_bind() and pptp_connect() Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 28/43] vlan: Fix untag operations of stacked vlans with REORDER_HEADER off Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 29/43] skbuff: Fix offset error in skb_reorder_vlan_header Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 30/43] net: check both type and procotol for tcp sockets Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 31/43] net_sched: make qdisc_tree_decrease_qlen() work for non mq Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 32/43] bluetooth: Validate socket address length in sco_sock_bind() Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 33/43] net: fix uninitialized variable issue Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 35/43] rhashtable: Enforce minimum size on initial hash table Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 36/43] fou: clean up socket with kfree_rcu Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 37/43] af_unix: Revert lock_interruptible in stream receive code Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 38/43] tcp: restore fastopen with no data in SYN packet Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 39/43] rhashtable: Fix walker list corruption Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 40/43] KEYS: Fix race between key destruction and finding a keyring by name Greg Kroah-Hartman
2016-01-20 23:10 ` Greg Kroah-Hartman [this message]
2016-01-20 23:10 ` [PATCH 4.1 42/43] KEYS: Fix race between read and revoke Greg Kroah-Hartman
2016-01-20 23:10 ` [PATCH 4.1 43/43] KEYS: Fix keyring ref leak in join_session_keyring() Greg Kroah-Hartman
2016-01-20 23:51 ` [PATCH 4.1 00/43] 4.1.16-stable review Shuah Khan
2016-01-21 12:23 ` Guenter Roeck
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