| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
HID: uclogic: Correct devm device reference for hidinput input_dev name
Reference the HID device rather than the input device for the devm
allocation of the input_dev name. Referencing the input_dev would lead to a
use-after-free when the input_dev was unregistered and subsequently fires a
uevent that depends on the name. At the point of firing the uevent, the
name would be freed by devres management.
Use devm_kasprintf to simplify the logic for allocating memory and
formatting the input_dev name string. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: aic94xx: fix use-after-free in device removal path
The asd_pci_remove() function fails to synchronize with pending tasklets
before freeing the asd_ha structure, leading to a potential
use-after-free vulnerability.
When a device removal is triggered (via hot-unplug or module unload),
race condition can occur.
The fix adds tasklet_kill() before freeing the asd_ha structure,
ensuring all scheduled tasklets complete before cleanup proceeds. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scpi: Ensure scpi_info is not assigned if the probe fails
When scpi probe fails, at any point, we need to ensure that the scpi_info
is not set and will remain NULL until the probe succeeds. If it is not
taken care, then it could result use-after-free as the value is exported
via get_scpi_ops() and could refer to a memory allocated via devm_kzalloc()
but freed when the probe fails. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Fix vm_bind_ioctl double free bug
If the argument check during an array bind fails, the bind_ops are freed
twice as seen below. Fix this by setting bind_ops to NULL after freeing.
==================================================================
BUG: KASAN: double-free in xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
Free of addr ffff88813bb9b800 by task xe_vm/14198
CPU: 5 UID: 0 PID: 14198 Comm: xe_vm Not tainted 6.16.0-xe-eudebug-cmanszew+ #520 PREEMPT(full)
Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR5 RVP, BIOS ADLPFWI1.R00.2411.A02.2110081023 10/08/2021
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
print_report+0xcb/0x610
? __virt_addr_valid+0x19a/0x300
? xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
kasan_report_invalid_free+0xc8/0xf0
? xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
? xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
check_slab_allocation+0x102/0x130
kfree+0x10d/0x440
? should_fail_ex+0x57/0x2f0
? xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
xe_vm_bind_ioctl+0x1b2/0x21f0 [xe]
? __pfx_xe_vm_bind_ioctl+0x10/0x10 [xe]
? __lock_acquire+0xab9/0x27f0
? lock_acquire+0x165/0x300
? drm_dev_enter+0x53/0xe0 [drm]
? find_held_lock+0x2b/0x80
? drm_dev_exit+0x30/0x50 [drm]
? drm_ioctl_kernel+0x128/0x1c0 [drm]
drm_ioctl_kernel+0x128/0x1c0 [drm]
? __pfx_xe_vm_bind_ioctl+0x10/0x10 [xe]
? find_held_lock+0x2b/0x80
? __pfx_drm_ioctl_kernel+0x10/0x10 [drm]
? should_fail_ex+0x57/0x2f0
? __pfx_xe_vm_bind_ioctl+0x10/0x10 [xe]
drm_ioctl+0x352/0x620 [drm]
? __pfx_drm_ioctl+0x10/0x10 [drm]
? __pfx_rpm_resume+0x10/0x10
? do_raw_spin_lock+0x11a/0x1b0
? find_held_lock+0x2b/0x80
? __pm_runtime_resume+0x61/0xc0
? rcu_is_watching+0x20/0x50
? trace_irq_enable.constprop.0+0xac/0xe0
xe_drm_ioctl+0x91/0xc0 [xe]
__x64_sys_ioctl+0xb2/0x100
? rcu_is_watching+0x20/0x50
do_syscall_64+0x68/0x2e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa9acb24ded
(cherry picked from commit a01b704527c28a2fd43a17a85f8996b75ec8492a) |
| In the Linux kernel, the following vulnerability has been resolved:
cnic: Fix use-after-free bugs in cnic_delete_task
The original code uses cancel_delayed_work() in cnic_cm_stop_bnx2x_hw(),
which does not guarantee that the delayed work item 'delete_task' has
fully completed if it was already running. Additionally, the delayed work
item is cyclic, the flush_workqueue() in cnic_cm_stop_bnx2x_hw() only
blocks and waits for work items that were already queued to the
workqueue prior to its invocation. Any work items submitted after
flush_workqueue() is called are not included in the set of tasks that the
flush operation awaits. This means that after the cyclic work items have
finished executing, a delayed work item may still exist in the workqueue.
This leads to use-after-free scenarios where the cnic_dev is deallocated
by cnic_free_dev(), while delete_task remains active and attempt to
dereference cnic_dev in cnic_delete_task().
A typical race condition is illustrated below:
CPU 0 (cleanup) | CPU 1 (delayed work callback)
cnic_netdev_event() |
cnic_stop_hw() | cnic_delete_task()
cnic_cm_stop_bnx2x_hw() | ...
cancel_delayed_work() | /* the queue_delayed_work()
flush_workqueue() | executes after flush_workqueue()*/
| queue_delayed_work()
cnic_free_dev(dev)//free | cnic_delete_task() //new instance
| dev = cp->dev; //use
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the cyclic delayed work item is properly canceled and that any
ongoing execution of the work item completes before the cnic_dev is
deallocated. Furthermore, since cancel_delayed_work_sync() uses
__flush_work(work, true) to synchronously wait for any currently
executing instance of the work item to finish, the flush_workqueue()
becomes redundant and should be removed.
This bug was identified through static analysis. To reproduce the issue
and validate the fix, I simulated the cnic PCI device in QEMU and
introduced intentional delays — such as inserting calls to ssleep()
within the cnic_delete_task() function — to increase the likelihood
of triggering the bug. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_hash - fix double free in hash_accept
If accept(2) is called on socket type algif_hash with
MSG_MORE flag set and crypto_ahash_import fails,
sk2 is freed. However, it is also freed in af_alg_release,
leading to slab-use-after-free error. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/iwcm: Fix use-after-free of work objects after cm_id destruction
The commit 59c68ac31e15 ("iw_cm: free cm_id resources on the last
deref") simplified cm_id resource management by freeing cm_id once all
references to the cm_id were removed. The references are removed either
upon completion of iw_cm event handlers or when the application destroys
the cm_id. This commit introduced the use-after-free condition where
cm_id_private object could still be in use by event handler works during
the destruction of cm_id. The commit aee2424246f9 ("RDMA/iwcm: Fix a
use-after-free related to destroying CM IDs") addressed this use-after-
free by flushing all pending works at the cm_id destruction.
However, still another use-after-free possibility remained. It happens
with the work objects allocated for each cm_id_priv within
alloc_work_entries() during cm_id creation, and subsequently freed in
dealloc_work_entries() once all references to the cm_id are removed.
If the cm_id's last reference is decremented in the event handler work,
the work object for the work itself gets removed, and causes the use-
after-free BUG below:
BUG: KASAN: slab-use-after-free in __pwq_activate_work+0x1ff/0x250
Read of size 8 at addr ffff88811f9cf800 by task kworker/u16:1/147091
CPU: 2 UID: 0 PID: 147091 Comm: kworker/u16:1 Not tainted 6.15.0-rc2+ #27 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
Workqueue: 0x0 (iw_cm_wq)
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x90
print_report+0x174/0x554
? __virt_addr_valid+0x208/0x430
? __pwq_activate_work+0x1ff/0x250
kasan_report+0xae/0x170
? __pwq_activate_work+0x1ff/0x250
__pwq_activate_work+0x1ff/0x250
pwq_dec_nr_in_flight+0x8c5/0xfb0
process_one_work+0xc11/0x1460
? __pfx_process_one_work+0x10/0x10
? assign_work+0x16c/0x240
worker_thread+0x5ef/0xfd0
? __pfx_worker_thread+0x10/0x10
kthread+0x3b0/0x770
? __pfx_kthread+0x10/0x10
? rcu_is_watching+0x11/0xb0
? _raw_spin_unlock_irq+0x24/0x50
? rcu_is_watching+0x11/0xb0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 147416:
kasan_save_stack+0x2c/0x50
kasan_save_track+0x10/0x30
__kasan_kmalloc+0xa6/0xb0
alloc_work_entries+0xa9/0x260 [iw_cm]
iw_cm_connect+0x23/0x4a0 [iw_cm]
rdma_connect_locked+0xbfd/0x1920 [rdma_cm]
nvme_rdma_cm_handler+0x8e5/0x1b60 [nvme_rdma]
cma_cm_event_handler+0xae/0x320 [rdma_cm]
cma_work_handler+0x106/0x1b0 [rdma_cm]
process_one_work+0x84f/0x1460
worker_thread+0x5ef/0xfd0
kthread+0x3b0/0x770
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
Freed by task 147091:
kasan_save_stack+0x2c/0x50
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kfree+0x13a/0x4b0
dealloc_work_entries+0x125/0x1f0 [iw_cm]
iwcm_deref_id+0x6f/0xa0 [iw_cm]
cm_work_handler+0x136/0x1ba0 [iw_cm]
process_one_work+0x84f/0x1460
worker_thread+0x5ef/0xfd0
kthread+0x3b0/0x770
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
Last potentially related work creation:
kasan_save_stack+0x2c/0x50
kasan_record_aux_stack+0xa3/0xb0
__queue_work+0x2ff/0x1390
queue_work_on+0x67/0xc0
cm_event_handler+0x46a/0x820 [iw_cm]
siw_cm_upcall+0x330/0x650 [siw]
siw_cm_work_handler+0x6b9/0x2b20 [siw]
process_one_work+0x84f/0x1460
worker_thread+0x5ef/0xfd0
kthread+0x3b0/0x770
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
This BUG is reproducible by repeating the blktests test case nvme/061
for the rdma transport and the siw driver.
To avoid the use-after-free of cm_id_private work objects, ensure that
the last reference to the cm_id is decremented not in the event handler
works, but in the cm_id destruction context. For that purpose, mo
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: call disconnect callback before deleting conn
In hci_cs_disconnect, we do hci_conn_del even if disconnection failed.
ISO, L2CAP and SCO connections refer to the hci_conn without
hci_conn_get, so disconn_cfm must be called so they can clean up their
conn, otherwise use-after-free occurs.
ISO:
==========================================================
iso_sock_connect:880: sk 00000000eabd6557
iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
...
iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073
hci_dev_put:1487: hci0 orig refcnt 17
__iso_chan_add:214: conn 00000000b6251073
iso_sock_clear_timer:117: sock 00000000eabd6557 state 3
...
hci_rx_work:4085: hci0 Event packet
hci_event_packet:7601: hci0: event 0x0f
hci_cmd_status_evt:4346: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3107: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560
hci_conn_unlink:1102: hci0: hcon 000000001696f1fd
hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2
hci_chan_list_flush:2780: hcon 000000001696f1fd
hci_dev_put:1487: hci0 orig refcnt 21
hci_dev_put:1487: hci0 orig refcnt 20
hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c
... <no iso_* activity on sk/conn> ...
iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557
BUG: kernel NULL pointer dereference, address: 0000000000000668
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth
==========================================================
L2CAP:
==================================================================
hci_cmd_status_evt:4359: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3085: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585
hci_conn_unlink:1102: hci0: hcon ffff88800c999000
hci_chan_list_flush:2780: hcon ffff88800c999000
hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280
...
BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth]
Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175
CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x90
print_report+0xcf/0x670
? __virt_addr_valid+0xf8/0x180
? hci_send_acl+0x2d/0x540 [bluetooth]
kasan_report+0xa8/0xe0
? hci_send_acl+0x2d/0x540 [bluetooth]
hci_send_acl+0x2d/0x540 [bluetooth]
? __pfx___lock_acquire+0x10/0x10
l2cap_chan_send+0x1fd/0x1300 [bluetooth]
? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth]
? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth]
? lock_release+0x1d5/0x3c0
? mark_held_locks+0x1a/0x90
l2cap_sock_sendmsg+0x100/0x170 [bluetooth]
sock_write_iter+0x275/0x280
? __pfx_sock_write_iter+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
do_iter_readv_writev+0x176/0x220
? __pfx_do_iter_readv_writev+0x10/0x10
? find_held_lock+0x83/0xa0
? selinux_file_permission+0x13e/0x210
do_iter_write+0xda/0x340
vfs_writev+0x1b4/0x400
? __pfx_vfs_writev+0x10/0x10
? __seccomp_filter+0x112/0x750
? populate_seccomp_data+0x182/0x220
? __fget_light+0xdf/0x100
? do_writev+0x19d/0x210
do_writev+0x19d/0x210
? __pfx_do_writev+0x10/0x10
? mark_held_locks+0x1a/0x90
do_syscall_64+0x60/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
? do_syscall_64+0x6c/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7ff45cb23e64
Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX:
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
bridge: mcast: Fix use-after-free during router port configuration
The bridge maintains a global list of ports behind which a multicast
router resides. The list is consulted during forwarding to ensure
multicast packets are forwarded to these ports even if the ports are not
member in the matching MDB entry.
When per-VLAN multicast snooping is enabled, the per-port multicast
context is disabled on each port and the port is removed from the global
router port list:
# ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1
# ip link add name dummy1 up master br1 type dummy
# ip link set dev dummy1 type bridge_slave mcast_router 2
$ bridge -d mdb show | grep router
router ports on br1: dummy1
# ip link set dev br1 type bridge mcast_vlan_snooping 1
$ bridge -d mdb show | grep router
However, the port can be re-added to the global list even when per-VLAN
multicast snooping is enabled:
# ip link set dev dummy1 type bridge_slave mcast_router 0
# ip link set dev dummy1 type bridge_slave mcast_router 2
$ bridge -d mdb show | grep router
router ports on br1: dummy1
Since commit 4b30ae9adb04 ("net: bridge: mcast: re-implement
br_multicast_{enable, disable}_port functions"), when per-VLAN multicast
snooping is enabled, multicast disablement on a port will disable the
per-{port, VLAN} multicast contexts and not the per-port one. As a
result, a port will remain in the global router port list even after it
is deleted. This will lead to a use-after-free [1] when the list is
traversed (when adding a new port to the list, for example):
# ip link del dev dummy1
# ip link add name dummy2 up master br1 type dummy
# ip link set dev dummy2 type bridge_slave mcast_router 2
Similarly, stale entries can also be found in the per-VLAN router port
list. When per-VLAN multicast snooping is disabled, the per-{port, VLAN}
contexts are disabled on each port and the port is removed from the
per-VLAN router port list:
# ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1
# ip link add name dummy1 up master br1 type dummy
# bridge vlan add vid 2 dev dummy1
# bridge vlan global set vid 2 dev br1 mcast_snooping 1
# bridge vlan set vid 2 dev dummy1 mcast_router 2
$ bridge vlan global show dev br1 vid 2 | grep router
router ports: dummy1
# ip link set dev br1 type bridge mcast_vlan_snooping 0
$ bridge vlan global show dev br1 vid 2 | grep router
However, the port can be re-added to the per-VLAN list even when
per-VLAN multicast snooping is disabled:
# bridge vlan set vid 2 dev dummy1 mcast_router 0
# bridge vlan set vid 2 dev dummy1 mcast_router 2
$ bridge vlan global show dev br1 vid 2 | grep router
router ports: dummy1
When the VLAN is deleted from the port, the per-{port, VLAN} multicast
context will not be disabled since multicast snooping is not enabled
on the VLAN. As a result, the port will remain in the per-VLAN router
port list even after it is no longer member in the VLAN. This will lead
to a use-after-free [2] when the list is traversed (when adding a new
port to the list, for example):
# ip link add name dummy2 up master br1 type dummy
# bridge vlan add vid 2 dev dummy2
# bridge vlan del vid 2 dev dummy1
# bridge vlan set vid 2 dev dummy2 mcast_router 2
Fix these issues by removing the port from the relevant (global or
per-VLAN) router port list in br_multicast_port_ctx_deinit(). The
function is invoked during port deletion with the per-port multicast
context and during VLAN deletion with the per-{port, VLAN} multicast
context.
Note that deleting the multicast router timer is not enough as it only
takes care of the temporary multicast router states (1 or 3) and not the
permanent one (2).
[1]
BUG: KASAN: slab-out-of-bounds in br_multicast_add_router.part.0+0x3f1/0x560
Write of size 8 at addr ffff888004a67328 by task ip/384
[...]
Call Trace:
<TASK>
dump_stack
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix off-by-one error in do_split
Syzkaller detected a use-after-free issue in ext4_insert_dentry that was
caused by out-of-bounds access due to incorrect splitting in do_split.
BUG: KASAN: use-after-free in ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109
Write of size 251 at addr ffff888074572f14 by task syz-executor335/5847
CPU: 0 UID: 0 PID: 5847 Comm: syz-executor335 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
__asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106
ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109
add_dirent_to_buf+0x3d9/0x750 fs/ext4/namei.c:2154
make_indexed_dir+0xf98/0x1600 fs/ext4/namei.c:2351
ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2455
ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2796
ext4_symlink+0x920/0xb50 fs/ext4/namei.c:3431
vfs_symlink+0x137/0x2e0 fs/namei.c:4615
do_symlinkat+0x222/0x3a0 fs/namei.c:4641
__do_sys_symlink fs/namei.c:4662 [inline]
__se_sys_symlink fs/namei.c:4660 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:4660
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
The following loop is located right above 'if' statement.
for (i = count-1; i >= 0; i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
size += map[i].size;
move++;
}
'i' in this case could go down to -1, in which case sum of active entries
wouldn't exceed half the block size, but previous behaviour would also do
split in half if sum would exceed at the very last block, which in case of
having too many long name files in a single block could lead to
out-of-bounds access and following use-after-free.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
eventpoll: don't decrement ep refcount while still holding the ep mutex
Jann Horn points out that epoll is decrementing the ep refcount and then
doing a
mutex_unlock(&ep->mtx);
afterwards. That's very wrong, because it can lead to a use-after-free.
That pattern is actually fine for the very last reference, because the
code in question will delay the actual call to "ep_free(ep)" until after
it has unlocked the mutex.
But it's wrong for the much subtler "next to last" case when somebody
*else* may also be dropping their reference and free the ep while we're
still using the mutex.
Note that this is true even if that other user is also using the same ep
mutex: mutexes, unlike spinlocks, can not be used for object ownership,
even if they guarantee mutual exclusion.
A mutex "unlock" operation is not atomic, and as one user is still
accessing the mutex as part of unlocking it, another user can come in
and get the now released mutex and free the data structure while the
first user is still cleaning up.
See our mutex documentation in Documentation/locking/mutex-design.rst,
in particular the section [1] about semantics:
"mutex_unlock() may access the mutex structure even after it has
internally released the lock already - so it's not safe for
another context to acquire the mutex and assume that the
mutex_unlock() context is not using the structure anymore"
So if we drop our ep ref before the mutex unlock, but we weren't the
last one, we may then unlock the mutex, another user comes in, drops
_their_ reference and releases the 'ep' as it now has no users - all
while the mutex_unlock() is still accessing it.
Fix this by simply moving the ep refcount dropping to outside the mutex:
the refcount itself is atomic, and doesn't need mutex protection (that's
the whole _point_ of refcounts: unlike mutexes, they are inherently
about object lifetimes). |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: Always pass notifications when child class becomes empty
Certain classful qdiscs may invoke their classes' dequeue handler on an
enqueue operation. This may unexpectedly empty the child qdisc and thus
make an in-flight class passive via qlen_notify(). Most qdiscs do not
expect such behaviour at this point in time and may re-activate the
class eventually anyways which will lead to a use-after-free.
The referenced fix commit attempted to fix this behavior for the HFSC
case by moving the backlog accounting around, though this turned out to
be incomplete since the parent's parent may run into the issue too.
The following reproducer demonstrates this use-after-free:
tc qdisc add dev lo root handle 1: drr
tc filter add dev lo parent 1: basic classid 1:1
tc class add dev lo parent 1: classid 1:1 drr
tc qdisc add dev lo parent 1:1 handle 2: hfsc def 1
tc class add dev lo parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0
tc qdisc add dev lo parent 2:1 handle 3: netem
tc qdisc add dev lo parent 3:1 handle 4: blackhole
echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888
tc class delete dev lo classid 1:1
echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888
Since backlog accounting issues leading to a use-after-frees on stale
class pointers is a recurring pattern at this point, this patch takes
a different approach. Instead of trying to fix the accounting, the patch
ensures that qdisc_tree_reduce_backlog always calls qlen_notify when
the child qdisc is empty. This solves the problem because deletion of
qdiscs always involves a call to qdisc_reset() and / or
qdisc_purge_queue() which ultimately resets its qlen to 0 thus causing
the following qdisc_tree_reduce_backlog() to report to the parent. Note
that this may call qlen_notify on passive classes multiple times. This
is not a problem after the recent patch series that made all the
classful qdiscs qlen_notify() handlers idempotent. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix mr->map double free
rxe_mr_cleanup() which tries to free mr->map again will be called when
rxe_mr_init_user() fails:
CPU: 0 PID: 4917 Comm: rdma_flush_serv Kdump: loaded Not tainted 6.1.0-rc1-roce-flush+ #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x5d
panic+0x19e/0x349
end_report.part.0+0x54/0x7c
kasan_report.cold+0xa/0xf
rxe_mr_cleanup+0x9d/0xf0 [rdma_rxe]
__rxe_cleanup+0x10a/0x1e0 [rdma_rxe]
rxe_reg_user_mr+0xb7/0xd0 [rdma_rxe]
ib_uverbs_reg_mr+0x26a/0x480 [ib_uverbs]
ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x1a2/0x250 [ib_uverbs]
ib_uverbs_cmd_verbs+0x1397/0x15a0 [ib_uverbs]
This issue was firstly exposed since commit b18c7da63fcb ("RDMA/rxe: Fix
memory leak in error path code") and then we fixed it in commit
8ff5f5d9d8cf ("RDMA/rxe: Prevent double freeing rxe_map_set()") but this
fix was reverted together at last by commit 1e75550648da (Revert
"RDMA/rxe: Create duplicate mapping tables for FMRs")
Simply let rxe_mr_cleanup() always handle freeing the mr->map once it is
successfully allocated. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: fix use-after-free in cmp_bss()
Following bss_free() quirk introduced in commit 776b3580178f
("cfg80211: track hidden SSID networks properly"), adjust
cfg80211_update_known_bss() to free the last beacon frame
elements only if they're not shared via the corresponding
'hidden_beacon_bss' pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915: mark requests for GuC virtual engines to avoid use-after-free
References to i915_requests may be trapped by userspace inside a
sync_file or dmabuf (dma-resv) and held indefinitely across different
proceses. To counter-act the memory leaks, we try to not to keep
references from the request past their completion.
On the other side on fence release we need to know if rq->engine
is valid and points to hw engine (true for non-virtual requests).
To make it possible extra bit has been added to rq->execution_mask,
for marking virtual engines.
(cherry picked from commit 280410677af763f3871b93e794a199cfcf6fb580) |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix use-after-free in snd_usb_mixer_free()
When snd_usb_create_mixer() fails, snd_usb_mixer_free() frees
mixer->id_elems but the controls already added to the card still
reference the freed memory. Later when snd_card_register() runs,
the OSS mixer layer calls their callbacks and hits a use-after-free read.
Call trace:
get_ctl_value+0x63f/0x820 sound/usb/mixer.c:411
get_min_max_with_quirks.isra.0+0x240/0x1f40 sound/usb/mixer.c:1241
mixer_ctl_feature_info+0x26b/0x490 sound/usb/mixer.c:1381
snd_mixer_oss_build_test+0x174/0x3a0 sound/core/oss/mixer_oss.c:887
...
snd_card_register+0x4ed/0x6d0 sound/core/init.c:923
usb_audio_probe+0x5ef/0x2a90 sound/usb/card.c:1025
Fix by calling snd_ctl_remove() for all mixer controls before freeing
id_elems. We save the next pointer first because snd_ctl_remove()
frees the current element. |
| In the Linux kernel, the following vulnerability has been resolved:
net_sched: hfsc: Fix a UAF vulnerability in class handling
This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class
handling. The issue occurs due to a time-of-check/time-of-use condition
in hfsc_change_class() when working with certain child qdiscs like netem
or codel.
The vulnerability works as follows:
1. hfsc_change_class() checks if a class has packets (q.qlen != 0)
2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g.,
codel, netem) might drop packets and empty the queue
3. The code continues assuming the queue is still non-empty, adding
the class to vttree
4. This breaks HFSC scheduler assumptions that only non-empty classes
are in vttree
5. Later, when the class is destroyed, this can lead to a Use-After-Free
The fix adds a second queue length check after qdisc_peek_len() to verify
the queue wasn't emptied. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()
Lei Lu recently reported that nfsd4_setclientid_confirm() did not check
the return value from get_client_locked(). a SETCLIENTID_CONFIRM could
race with a confirmed client expiring and fail to get a reference. That
could later lead to a UAF.
Fix this by getting a reference early in the case where there is an
extant confirmed client. If that fails then treat it as if there were no
confirmed client found at all.
In the case where the unconfirmed client is expiring, just fail and
return the result from get_client_locked(). |
| ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-50 and 7.1.2-25, when an allocation fails in CheckPrimitiveExtent this can result in a heap-use-after-free and result in a crash. This issue has been patched in versions 6.9.13-50 and 7.1.2-25. |
| ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2.23 and 6.9.13-48, a crafted MSL image can trigger a heap-use-after-free. Versions 7.1.2.23 and 6.9.13-48 fix the issue. |
