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 3.14 45/47] KEYS: Fix crash when attempt to garbage collect an uninstantiated keyring
Date: Wed, 20 Jan 2016 14:01:17 -0800 [thread overview]
Message-ID: <20160120215514.370546435@linuxfoundation.org> (raw)
In-Reply-To: <20160120215507.575738941@linuxfoundation.org>
3.14-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
@@ -143,8 +143,10 @@ 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 22:01 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 22:00 [PATCH 3.14 00/47] 3.14.59-stable review Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 01/47] unix: avoid use-after-free in ep_remove_wait_queue Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 02/47] tools/net: Use include/uapi with __EXPORTED_HEADERS__ Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 03/47] packet: do skb_probe_transport_header when we actually have data Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 04/47] packet: always probe for transport header Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 05/47] packet: infer protocol from ethernet header if unset Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 06/47] sctp: translate host order to network order when setting a hmacid Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 07/47] ip_tunnel: disable preemption when updating per-cpu tstats Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 08/47] snmp: Remove duplicate OUTMCAST stat increment Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 10/47] tcp: md5: fix lockdep annotation Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 11/47] tcp: initialize tp->copied_seq in case of cross SYN connection Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 12/47] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 13/47] net: ipmr: fix static mfc/dev leaks on table destruction Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 14/47] net: ip6mr: " Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 15/47] broadcom: fix PHY_ID_BCM5481 entry in the id table Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 16/47] ipv6: distinguish frag queues by device for multicast and link-local packets Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 17/47] ipv6: sctp: implement sctp_v6_destroy_sock() Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 18/47] Btrfs: fix race leading to incorrect item deletion when dropping extents Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 19/47] Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 20/47] ext4: fix potential use after free in __ext4_journal_stop Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 21/47] ext4, jbd2: ensure entering into panic after recording an error in superblock Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 22/47] firewire: ohci: fix JMicron JMB38x IT context discovery Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 23/47] nfs4: start callback_ident at idr 1 Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 24/47] nfs: if we have no valid attrs, then dont declare the attribute cache valid Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 25/47] ocfs2: fix umask ignored issue Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 26/47] USB: cdc_acm: Ignore Infineon Flash Loader utility Greg Kroah-Hartman
2016-01-20 22:00 ` [PATCH 3.14 27/47] USB: serial: Another Infineon flash loader USB ID Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 28/47] USB: cp210x: Remove CP2110 ID from compatibility list Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 29/47] USB: add quirk for devices with broken LPM Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 30/47] USB: whci-hcd: add check for dma mapping error Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 31/47] usb: Use the USB_SS_MULT() macro to decode burst multiplier for log message Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 32/47] gre6: allow to update all parameters via rtnl Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 33/47] atl1c: Improve driver not to do order 4 GFP_ATOMIC allocation Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 34/47] sctp: use the same clock as if sock source timestamps were on Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 35/47] sctp: update the netstamp_needed counter when copying sockets Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 36/47] ipv6: sctp: clone options to avoid use after free Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 38/47] sh_eth: fix kernel oops in skb_put() Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 39/47] vlan: Fix untag operations of stacked vlans with REORDER_HEADER off Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 40/47] skbuff: Fix offset error in skb_reorder_vlan_header Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 41/47] pptp: verify sockaddr_len in pptp_bind() and pptp_connect() Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 42/47] bluetooth: Validate socket address length in sco_sock_bind() Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 43/47] af_unix: Revert lock_interruptible in stream receive code Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 44/47] KEYS: Fix race between key destruction and finding a keyring by name Greg Kroah-Hartman
2016-01-20 22:01 ` Greg Kroah-Hartman [this message]
2016-01-20 22:01 ` [PATCH 3.14 46/47] KEYS: Fix race between read and revoke Greg Kroah-Hartman
2016-01-20 22:01 ` [PATCH 3.14 47/47] KEYS: Fix keyring ref leak in join_session_keyring() Greg Kroah-Hartman
2016-01-20 23:15 ` [PATCH 3.14 00/47] 3.14.59-stable review Shuah Khan
2016-01-21 12:21 ` Guenter Roeck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160120215514.370546435@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=dhowells@redhat.com \
--cc=dvyukov@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).