[ Upstream commit 4a74da044ec9ec8679e6beccc4306b936b62873f ]
KASAN reports an out of bounds read:
BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36
BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline]
BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410
security/keys/permission.c:54
Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362
CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15
Call Trace:
__dump_stack lib/dump_stack.c:82 [inline]
dump_stack+0x107/0x167 lib/dump_stack.c:123
print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400
__kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
kasan_report+0x3a/0x50 mm/kasan/report.c:585
__kuid_val include/linux/uidgid.h:36 [inline]
uid_eq include/linux/uidgid.h:63 [inline]
key_task_permission+0x394/0x410 security/keys/permission.c:54
search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793
This issue was also reported by syzbot.
It can be reproduced by following these steps(more details [1]):
1. Obtain more than 32 inputs that have similar hashes, which ends with the
pattern '0xxxxxxxe6'.
2. Reboot and add the keys obtained in step 1.
The reproducer demonstrates how this issue happened:
1. In the search_nested_keyrings function, when it iterates through the
slots in a node(below tag ascend_to_node), if the slot pointer is meta
and node->back_pointer != NULL(it means a root), it will proceed to
descend_to_node. However, there is an exception. If node is the root,
and one of the slots points to a shortcut, it will be treated as a
keyring.
2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function.
However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as
ASSOC_ARRAY_PTR_SUBTYPE_MASK.
3. When 32 keys with the similar hashes are added to the tree, the ROOT
has keys with hashes that are not similar (e.g. slot 0) and it splits
NODE A without using a shortcut. When NODE A is filled with keys that
all hashes are xxe6, the keys are similar, NODE A will split with a
shortcut. Finally, it forms the tree as shown below, where slot 6 points
to a shortcut.
NODE A
+------>+---+
ROOT | | 0 | xxe6
+---+ | +---+
xxxx | 0 | shortcut : : xxe6
+---+ | +---+
xxe6 : : | | | xxe6
+---+ | +---+
| 6 |---+ : : xxe6
+---+ +---+
xxe6 : : | f | xxe6
+---+ +---+
xxe6 | f |
+---+
4. As mentioned above, If a slot(slot 6) of the root points to a shortcut,
it may be mistakenly transferred to a key*, leading to a read
out-of-bounds read.
To fix this issue, one should jump to descend_to_node if the ptr is a
shortcut, regardless of whether the node is root or not.
[1] https://lore.kernel.org/linux-kernel/1cfa878e-8c7b-4570-8606-21daf5e13ce7@huaweicloud.com/
[jarkko: tweaked the commit message a bit to have an appropriate closes
tag.]
Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring")
Reported-by: syzbot+5b415c07907a2990d1a3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000cbb7860611f61147@google.com/T/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream.
A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9da27fb65a14c18efd4473e2e82b76b53ba60252 upstream.
The expiry time of a key is unconditionally overwritten during
instantiation, defaulting to turn it permanent. This causes a problem
for DNS resolution as the expiration set by user-space is overwritten to
TIME64_MAX, disabling further DNS updates. Fix this by restoring the
condition that key_set_expiry is only called when the pre-parser sets a
specific expiry.
Fixes: 39299bdd2546 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
Signed-off-by: Silvio Gissi <sifonsec@amazon.com>
cc: David Howells <dhowells@redhat.com>
cc: Hazem Mohamed Abuelfotoh <abuehaze@amazon.com>
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 39299bdd2546688d92ed9db4948f6219ca1b9542 ]
If a key has an expiration time, then when that time passes, the key is
left around for a certain amount of time before being collected (5 mins by
default) so that EKEYEXPIRED can be returned instead of ENOKEY. This is a
problem for DNS keys because we want to redo the DNS lookup immediately at
that point.
Fix this by allowing key types to be marked such that keys of that type
don't have this extra period, but are reclaimed as soon as they expire and
turn this on for dns_resolver-type keys. To make this easier to handle,
key->expiry is changed to be permanent if TIME64_MAX rather than 0.
Furthermore, give such new-style negative DNS results a 1s default expiry
if no other expiry time is set rather than allowing it to stick around
indefinitely. This shouldn't be zero as ls will follow a failing stat call
immediately with a second with AT_SYMLINK_NOFOLLOW added.
Fixes: 1a4240f4764a ("DNS: Separate out CIFS DNS Resolver code")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: Wang Lei <wang840925@gmail.com>
cc: Jeff Layton <jlayton@redhat.com>
cc: Steve French <smfrench@gmail.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jarkko Sakkinen <jarkko@kernel.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
