David Howells 096fe9eaea KEYS: Fix handling of stored error in a negatively instantiated user key ... If a user key gets negatively instantiated, an error code is cached in the payload area. A negatively instantiated key may be then be positively instantiated by updating it with valid data. However, the ->update key type method must be aware that the error code may be there. The following may be used to trigger the bug in the user key type: keyctl request2 user user "" @u keyctl add user user "a" @u which manifests itself as: BUG: unable to handle kernel paging request at 00000000ffffff8a IP: [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046 PGD 7cc30067 PUD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 3 PID: 2644 Comm: a.out Not tainted 4.3.0+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003ddea700 ti: ffff88003dd88000 task.ti: ffff88003dd88000 RIP: 0010:[<ffffffff810a376f>] [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 [<ffffffff810a376f>] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046 RSP: 0018:ffff88003dd8bdb0 EFLAGS: 00010246 RAX: 00000000ffffff82 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffffffff81e3fe40 RSI: 0000000000000000 RDI: 00000000ffffff82 RBP: ffff88003dd8bde0 R08: ffff88007d2d2da0 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88003e8073c0 R12: 00000000ffffff82 R13: ffff88003dd8be68 R14: ffff88007d027600 R15: ffff88003ddea700 FS: 0000000000b92880(0063) GS:ffff88007fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000ffffff8a CR3: 000000007cc5f000 CR4: 00000000000006e0 Stack: ffff88003dd8bdf0 ffffffff81160a8a 0000000000000000 00000000ffffff82 ffff88003dd8be68 ffff88007d027600 ffff88003dd8bdf0 ffffffff810a39e5 ffff88003dd8be20 ffffffff812a31ab ffff88007d027600 ffff88007d027620 Call Trace: [<ffffffff810a39e5>] kfree_call_rcu+0x15/0x20 kernel/rcu/tree.c:3136 [<ffffffff812a31ab>] user_update+0x8b/0xb0 security/keys/user_defined.c:129 [< inline >] __key_update security/keys/key.c:730 [<ffffffff8129e5c1>] key_create_or_update+0x291/0x440 security/keys/key.c:908 [< inline >] SYSC_add_key security/keys/keyctl.c:125 [<ffffffff8129fc21>] SyS_add_key+0x101/0x1e0 security/keys/keyctl.c:60 [<ffffffff8185f617>] entry_SYSCALL_64_fastpath+0x12/0x6a arch/x86/entry/entry_64.S:185 Note the error code (-ENOKEY) in EDX. A similar bug can be tripped by: keyctl request2 trusted user "" @u keyctl add trusted user "a" @u This should also affect encrypted keys - but that has to be correctly parameterised or it will fail with EINVAL before getting to the bit that will crashes. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com>		2015-11-25 14:19:47 +11:00
..
ecryptfs_format.c	encrypted-keys: create encrypted-keys directory	2011-09-14 15:22:26 -04:00
ecryptfs_format.h	encrypted-keys: create encrypted-keys directory	2011-09-14 15:22:26 -04:00
encrypted.c	KEYS: Fix handling of stored error in a negatively instantiated user key	2015-11-25 14:19:47 +11:00
encrypted.h	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00
Makefile	encrypted-keys: module build fixes	2011-11-16 14:23:14 -05:00
masterkey_trusted.c	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00