Linux: >> Linux Kernel >> 3.8.4 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: u_audio: don't let userspace block driver unbind
In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free()
via g_audio_cleanup() will disconnect the card and then wait for all
resources to be released, which happens when the refcount falls to zero.
Since userspace can keep the refcount incremented by not closing the
relevant file descriptor, the call to unbind may block indefinitely.
This can cause a deadlock during reboot, as evidenced by the following
blocked task observed on my machine:
task:reboot state:D stack:0 pid:2827 ppid:569 flags:0x0000000c
Call trace:
__switch_to+0xc8/0x140
__schedule+0x2f0/0x7c0
schedule+0x60/0xd0
schedule_timeout+0x180/0x1d4
wait_for_completion+0x78/0x180
snd_card_free+0x90/0xa0
g_audio_cleanup+0x2c/0x64
afunc_unbind+0x28/0x60
...
kernel_restart+0x4c/0xac
__do_sys_reboot+0xcc/0x1ec
__arm64_sys_reboot+0x28/0x30
invoke_syscall+0x4c/0x110
...
The issue can also be observed by opening the card with arecord and
then stopping the process through the shell before unbinding:
# arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo
^Z[1]+ Stopped arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
# echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind
(observe that the unbind command never finishes)
Fix the problem by using snd_card_free_when_closed() instead, which will
still disconnect the card as desired, but defer the task of freeing the
resources to the core once userspace closes its file descriptor.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace
Call kvm_init() only after _all_ setup is complete, as kvm_init() exposes
/dev/kvm to userspace and thus allows userspace to create VMs (and call
other ioctls). E.g. KVM will encounter a NULL pointer when attempting to
add a vCPU to the per-CPU loaded_vmcss_on_cpu list if userspace is able to
create a VM before vmx_init() configures said list.
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP
CPU: 6 PID: 1143 Comm: stable Not tainted 6.0.0-rc7+ #988
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:vmx_vcpu_load_vmcs+0x68/0x230 [kvm_intel]
<TASK>
vmx_vcpu_load+0x16/0x60 [kvm_intel]
kvm_arch_vcpu_load+0x32/0x1f0 [kvm]
vcpu_load+0x2f/0x40 [kvm]
kvm_arch_vcpu_create+0x231/0x310 [kvm]
kvm_vm_ioctl+0x79f/0xe10 [kvm]
? handle_mm_fault+0xb1/0x220
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f5a6b05743b
</TASK>
Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel(+) kvm irqbypass
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy()
The ioctl helper function nilfs_ioctl_wrap_copy(), which exchanges a
metadata array to/from user space, may copy uninitialized buffer regions
to user space memory for read-only ioctl commands NILFS_IOCTL_GET_SUINFO
and NILFS_IOCTL_GET_CPINFO.
This can occur when the element size of the user space metadata given by
the v_size member of the argument nilfs_argv structure is larger than the
size of the metadata element (nilfs_suinfo structure or nilfs_cpinfo
structure) on the file system side.
KMSAN-enabled kernels detect this issue as follows:
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user
include/linux/instrumented.h:121 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:33
instrument_copy_to_user include/linux/instrumented.h:121 [inline]
_copy_to_user+0xc0/0x100 lib/usercopy.c:33
copy_to_user include/linux/uaccess.h:169 [inline]
nilfs_ioctl_wrap_copy+0x6fa/0xc10 fs/nilfs2/ioctl.c:99
nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
__do_compat_sys_ioctl fs/ioctl.c:968 [inline]
__se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
__ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Uninit was created at:
__alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572
alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287
__get_free_pages+0x34/0xc0 mm/page_alloc.c:5599
nilfs_ioctl_wrap_copy+0x223/0xc10 fs/nilfs2/ioctl.c:74
nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
__do_compat_sys_ioctl fs/ioctl.c:968 [inline]
__se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
__ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Bytes 16-127 of 3968 are uninitialized
...
This eliminates the leak issue by initializing the page allocated as
buffer using get_zeroed_page().
CVSS Score
7.1
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Check kzalloc() in lpfc_sli4_cgn_params_read()
If kzalloc() fails in lpfc_sli4_cgn_params_read(), then we rely on
lpfc_read_object()'s routine to NULL check pdata.
Currently, an early return error is thrown from lpfc_read_object() to
protect us from NULL ptr dereference, but the errno code is -ENODEV.
Change the errno code to a more appropriate -ENOMEM.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()
After making all ->qlen_notify() callbacks idempotent, now it is safe to
remove the check of qlen!=0 from both fq_codel_dequeue() and
codel_qdisc_dequeue().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix WARNING in __ip_vs_cleanup_batch()
During the initialization of ip_vs_conn_net_init(), if file ip_vs_conn
or ip_vs_conn_sync fails to be created, the initialization is successful
by default. Therefore, the ip_vs_conn or ip_vs_conn_sync file doesn't
be found during the remove.
The following is the stack information:
name 'ip_vs_conn_sync'
WARNING: CPU: 3 PID: 9 at fs/proc/generic.c:712
remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
Call Trace:
<TASK>
__ip_vs_cleanup_batch+0x7d/0x120
ops_exit_list+0x125/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu
Fix the race condition between the following two flows that run in
parallel:
1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) ->
__sock_queue_rcv_skb.
2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram.
An SKB can be queued by the first flow and immediately dequeued and
freed by the second flow, therefore the callers of l2cap_reassemble_sdu
can't use the SKB after that function returns. However, some places
continue accessing struct l2cap_ctrl that resides in the SKB's CB for a
short time after l2cap_reassemble_sdu returns, leading to a
use-after-free condition (the stack trace is below, line numbers for
kernel 5.19.8).
Fix it by keeping a local copy of struct l2cap_ctrl.
BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169
Workqueue: hci0 hci_rx_work [bluetooth]
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429)
? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493)
? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth
ret_from_fork (arch/x86/entry/entry_64.S:306)
</TASK>
Allocated by task 43169:
kasan_save_stack (mm/kasan/common.c:39)
__kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293)
__alloc_skb (net/core/skbuff.c:414)
l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth
l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth
hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth
process_one_work (kernel/workqueue.c:2289)
worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437)
kthread (kernel/kthread.c:376)
ret_from_fork (arch/x86/entry/entry_64.S:306)
Freed by task 27920:
kasan_save_stack (mm/kasan/common.c:39)
kasan_set_track (mm/kasan/common.c:45)
kasan_set_free_info (mm/kasan/generic.c:372)
____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328)
slab_free_freelist_hook (mm/slub.c:1780)
kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553)
skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323)
bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth
l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth
sock_read_iter (net/socket.c:1087)
new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401)
vfs_read (fs/read_write.c:482)
ksys_read (fs/read_write.c:620)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix inode list leak during backref walking at resolve_indirect_refs()
During backref walking, at resolve_indirect_refs(), if we get an error
we jump to the 'out' label and call ulist_free() on the 'parents' ulist,
which frees all the elements in the ulist - however that does not free
any inode lists that may be attached to elements, through the 'aux' field
of a ulist node, so we end up leaking lists if we have any attached to
the unodes.
Fix this by calling free_leaf_list() instead of ulist_free() when we exit
from resolve_indirect_refs(). The static function free_leaf_list() is
moved up for this to be possible and it's slightly simplified by removing
unnecessary code.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
mISDN: fix possible memory leak in mISDN_register_device()
Afer commit 1fa5ae857bb1 ("driver core: get rid of struct device's
bus_id string array"), the name of device is allocated dynamically,
add put_device() to give up the reference, so that the name can be
freed in kobject_cleanup() when the refcount is 0.
Set device class before put_device() to avoid null release() function
WARN message in device_release().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix WARNING in ip_vs_app_net_cleanup()
During the initialization of ip_vs_app_net_init(), if file ip_vs_app
fails to be created, the initialization is successful by default.
Therefore, the ip_vs_app file doesn't be found during the remove in
ip_vs_app_net_cleanup(). It will cause WRNING.
The following is the stack information:
name 'ip_vs_app'
WARNING: CPU: 1 PID: 9 at fs/proc/generic.c:712 remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
Call Trace:
<TASK>
ops_exit_list+0x125/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01