2017-10-29 01:48:53 -04:00
|
|
|
From 8d4a2ec1e0b41b0cf9a0c5cd4511da7f8e4f3de2 Mon Sep 17 00:00:00 2001
|
|
|
|
|
From: Jerome Marchand <jmarchan@redhat.com>
|
|
|
|
|
Date: Wed, 6 Apr 2016 14:06:48 +0100
|
2017-11-07 17:32:46 -05:00
|
|
|
Subject: assoc_array: don't call compare_object() on a node
|
2017-10-29 01:48:53 -04:00
|
|
|
|
|
|
|
|
Changes since V1: fixed the description and added KASan warning.
|
|
|
|
|
|
|
|
|
|
In assoc_array_insert_into_terminal_node(), we call the
|
|
|
|
|
compare_object() method on all non-empty slots, even when they're
|
|
|
|
|
not leaves, passing a pointer to an unexpected structure to
|
|
|
|
|
compare_object(). Currently it causes an out-of-bound read access
|
|
|
|
|
in keyring_compare_object detected by KASan (see below). The issue
|
|
|
|
|
is easily reproduced with keyutils testsuite.
|
|
|
|
|
Only call compare_object() when the slot is a leave.
|
|
|
|
|
|
|
|
|
|
KASan warning:
|
|
|
|
|
==================================================================
|
|
|
|
|
BUG: KASAN: slab-out-of-bounds in keyring_compare_object+0x213/0x240 at addr ffff880060a6f838
|
|
|
|
|
Read of size 8 by task keyctl/1655
|
|
|
|
|
=============================================================================
|
|
|
|
|
BUG kmalloc-192 (Not tainted): kasan: bad access detected
|
|
|
|
|
-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
Disabling lock debugging due to kernel taint
|
|
|
|
|
INFO: Allocated in assoc_array_insert+0xfd0/0x3a60 age=69 cpu=1 pid=1647
|
|
|
|
|
___slab_alloc+0x563/0x5c0
|
|
|
|
|
__slab_alloc+0x51/0x90
|
|
|
|
|
kmem_cache_alloc_trace+0x263/0x300
|
|
|
|
|
assoc_array_insert+0xfd0/0x3a60
|
|
|
|
|
__key_link_begin+0xfc/0x270
|
|
|
|
|
key_create_or_update+0x459/0xaf0
|
|
|
|
|
SyS_add_key+0x1ba/0x350
|
|
|
|
|
entry_SYSCALL_64_fastpath+0x12/0x76
|
|
|
|
|
INFO: Slab 0xffffea0001829b80 objects=16 used=8 fp=0xffff880060a6f550 flags=0x3fff8000004080
|
|
|
|
|
INFO: Object 0xffff880060a6f740 @offset=5952 fp=0xffff880060a6e5d1
|
|
|
|
|
|
|
|
|
|
Bytes b4 ffff880060a6f730: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f740: d1 e5 a6 60 00 88 ff ff 0e 00 00 00 00 00 00 00 ...`............
|
|
|
|
|
Object ffff880060a6f750: 02 cf 8e 60 00 88 ff ff 02 c0 8e 60 00 88 ff ff ...`.......`....
|
|
|
|
|
Object ffff880060a6f760: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f770: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f790: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7d0: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
Object ffff880060a6f7f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
|
|
|
|
|
CPU: 0 PID: 1655 Comm: keyctl Tainted: G B 4.5.0-rc4-kasan+ #291
|
|
|
|
|
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
|
|
|
|
|
0000000000000000 000000001b2800b4 ffff880060a179e0 ffffffff81b60491
|
|
|
|
|
ffff88006c802900 ffff880060a6f740 ffff880060a17a10 ffffffff815e2969
|
|
|
|
|
ffff88006c802900 ffffea0001829b80 ffff880060a6f740 ffff880060a6e650
|
|
|
|
|
Call Trace:
|
|
|
|
|
[<ffffffff81b60491>] dump_stack+0x85/0xc4
|
|
|
|
|
[<ffffffff815e2969>] print_trailer+0xf9/0x150
|
|
|
|
|
[<ffffffff815e9454>] object_err+0x34/0x40
|
|
|
|
|
[<ffffffff815ebe50>] kasan_report_error+0x230/0x550
|
|
|
|
|
[<ffffffff819949be>] ? keyring_get_key_chunk+0x13e/0x210
|
|
|
|
|
[<ffffffff815ec62d>] __asan_report_load_n_noabort+0x5d/0x70
|
|
|
|
|
[<ffffffff81994cc3>] ? keyring_compare_object+0x213/0x240
|
|
|
|
|
[<ffffffff81994cc3>] keyring_compare_object+0x213/0x240
|
|
|
|
|
[<ffffffff81bc238c>] assoc_array_insert+0x86c/0x3a60
|
|
|
|
|
[<ffffffff81bc1b20>] ? assoc_array_cancel_edit+0x70/0x70
|
|
|
|
|
[<ffffffff8199797d>] ? __key_link_begin+0x20d/0x270
|
|
|
|
|
[<ffffffff8199786c>] __key_link_begin+0xfc/0x270
|
|
|
|
|
[<ffffffff81993389>] key_create_or_update+0x459/0xaf0
|
|
|
|
|
[<ffffffff8128ce0d>] ? trace_hardirqs_on+0xd/0x10
|
|
|
|
|
[<ffffffff81992f30>] ? key_type_lookup+0xc0/0xc0
|
|
|
|
|
[<ffffffff8199e19d>] ? lookup_user_key+0x13d/0xcd0
|
|
|
|
|
[<ffffffff81534763>] ? memdup_user+0x53/0x80
|
|
|
|
|
[<ffffffff819983ea>] SyS_add_key+0x1ba/0x350
|
|
|
|
|
[<ffffffff81998230>] ? key_get_type_from_user.constprop.6+0xa0/0xa0
|
|
|
|
|
[<ffffffff828bcf4e>] ? retint_user+0x18/0x23
|
|
|
|
|
[<ffffffff8128cc7e>] ? trace_hardirqs_on_caller+0x3fe/0x580
|
|
|
|
|
[<ffffffff81004017>] ? trace_hardirqs_on_thunk+0x17/0x19
|
|
|
|
|
[<ffffffff828bc432>] entry_SYSCALL_64_fastpath+0x12/0x76
|
|
|
|
|
Memory state around the buggy address:
|
|
|
|
|
ffff880060a6f700: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
|
|
|
|
|
ffff880060a6f780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
|
|
|
|
|
>ffff880060a6f800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
|
|
|
|
|
^
|
|
|
|
|
ffff880060a6f880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
|
|
|
|
|
ffff880060a6f900: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00
|
|
|
|
|
==================================================================
|
|
|
|
|
|
|
|
|
|
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
|
|
|
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
|
|
|
cc: stable@vger.kernel.org
|
|
|
|
|
---
|
|
|
|
|
lib/assoc_array.c | 4 +++-
|
|
|
|
|
1 file changed, 3 insertions(+), 1 deletion(-)
|
|
|
|
|
|
|
|
|
|
diff --git a/lib/assoc_array.c b/lib/assoc_array.c
|
2017-11-07 17:32:46 -05:00
|
|
|
index 03dd576..59fd7c0 100644
|
2017-10-29 01:48:53 -04:00
|
|
|
--- a/lib/assoc_array.c
|
|
|
|
|
+++ b/lib/assoc_array.c
|
|
|
|
|
@@ -524,7 +524,9 @@ static bool assoc_array_insert_into_terminal_node(struct assoc_array_edit *edit,
|
|
|
|
|
free_slot = i;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
- if (ops->compare_object(assoc_array_ptr_to_leaf(ptr), index_key)) {
|
|
|
|
|
+ if (assoc_array_ptr_is_leaf(ptr) &&
|
|
|
|
|
+ ops->compare_object(assoc_array_ptr_to_leaf(ptr),
|
|
|
|
|
+ index_key)) {
|
|
|
|
|
pr_devel("replace in slot %d\n", i);
|
|
|
|
|
edit->leaf_p = &node->slots[i];
|
|
|
|
|
edit->dead_leaf = node->slots[i];
|
2017-11-07 17:32:46 -05:00
|
|
|
--
|
|
|
|
|
cgit v1.1
|
|
|
|
|
|
