Linux: >> Linux Kernel >> 6.1.124 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
geneve: Fix use-after-free in geneve_find_dev().
syzkaller reported a use-after-free in geneve_find_dev() [0]
without repro.
geneve_configure() links struct geneve_dev.next to
net_generic(net, geneve_net_id)->geneve_list.
The net here could differ from dev_net(dev) if IFLA_NET_NS_PID,
IFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set.
When dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally
calls unregister_netdevice_queue() for each dev in the netns,
and later the dev is freed.
However, its geneve_dev.next is still linked to the backend UDP
socket netns.
Then, use-after-free will occur when another geneve dev is created
in the netns.
Let's call geneve_dellink() instead in geneve_destroy_tunnels().
[0]:
BUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline]
BUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
Read of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441
CPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d
Hardware name: linux,dummy-virt (DT)
Call trace:
show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x16c/0x6f0 mm/kasan/report.c:489
kasan_report+0xc0/0x120 mm/kasan/report.c:602
__asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379
geneve_find_dev drivers/net/geneve.c:1295 [inline]
geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634
rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795
__rtnl_newlink net/core/rtnetlink.c:3906 [inline]
rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:713 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x410/0x6f8 net/socket.c:2568
___sys_sendmsg+0x178/0x1d8 net/socket.c:2622
__sys_sendmsg net/socket.c:2654 [inline]
__do_sys_sendmsg net/socket.c:2659 [inline]
__se_sys_sendmsg net/socket.c:2657 [inline]
__arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132
do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151
el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600
Allocated by task 13247:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x68 mm/kasan/common.c:68
kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4298 [inline]
__kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304
__kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645
alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470
rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604
rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780
__rtnl_newlink net/core/rtnetlink.c:3906 [inline]
rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
netlink_unicast_kernel net/netlink/af_n
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: f_midi: f_midi_complete to call queue_work
When using USB MIDI, a lock is attempted to be acquired twice through a
re-entrant call to f_midi_transmit, causing a deadlock.
Fix it by using queue_work() to schedule the inner f_midi_transmit() via
a high priority work queue from the completion handler.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
nfp: bpf: Add check for nfp_app_ctrl_msg_alloc()
Add check for the return value of nfp_app_ctrl_msg_alloc() in
nfp_bpf_cmsg_alloc() to prevent null pointer dereference.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix double accounting race when btrfs_run_delalloc_range() failed
[BUG]
When running btrfs with block size (4K) smaller than page size (64K,
aarch64), there is a very high chance to crash the kernel at
generic/750, with the following messages:
(before the call traces, there are 3 extra debug messages added)
BTRFS warning (device dm-3): read-write for sector size 4096 with page size 65536 is experimental
BTRFS info (device dm-3): checking UUID tree
hrtimer: interrupt took 5451385 ns
BTRFS error (device dm-3): cow_file_range failed, root=4957 inode=257 start=1605632 len=69632: -28
BTRFS error (device dm-3): run_delalloc_nocow failed, root=4957 inode=257 start=1605632 len=69632: -28
BTRFS error (device dm-3): failed to run delalloc range, root=4957 ino=257 folio=1572864 submit_bitmap=8-15 start=1605632 len=69632: -28
------------[ cut here ]------------
WARNING: CPU: 2 PID: 3020984 at ordered-data.c:360 can_finish_ordered_extent+0x370/0x3b8 [btrfs]
CPU: 2 UID: 0 PID: 3020984 Comm: kworker/u24:1 Tainted: G OE 6.13.0-rc1-custom+ #89
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
pc : can_finish_ordered_extent+0x370/0x3b8 [btrfs]
lr : can_finish_ordered_extent+0x1ec/0x3b8 [btrfs]
Call trace:
can_finish_ordered_extent+0x370/0x3b8 [btrfs] (P)
can_finish_ordered_extent+0x1ec/0x3b8 [btrfs] (L)
btrfs_mark_ordered_io_finished+0x130/0x2b8 [btrfs]
extent_writepage+0x10c/0x3b8 [btrfs]
extent_write_cache_pages+0x21c/0x4e8 [btrfs]
btrfs_writepages+0x94/0x160 [btrfs]
do_writepages+0x74/0x190
filemap_fdatawrite_wbc+0x74/0xa0
start_delalloc_inodes+0x17c/0x3b0 [btrfs]
btrfs_start_delalloc_roots+0x17c/0x288 [btrfs]
shrink_delalloc+0x11c/0x280 [btrfs]
flush_space+0x288/0x328 [btrfs]
btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
process_one_work+0x228/0x680
worker_thread+0x1bc/0x360
kthread+0x100/0x118
ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1605632 OE len=16384 to_dec=16384 left=0
BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1622016 OE len=12288 to_dec=12288 left=0
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1634304 OE len=8192 to_dec=4096 left=0
CPU: 1 UID: 0 PID: 3286940 Comm: kworker/u24:3 Tainted: G W OE 6.13.0-rc1-custom+ #89
Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
Workqueue: btrfs_work_helper [btrfs] (btrfs-endio-write)
pstate: 404000c5 (nZcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : process_one_work+0x110/0x680
lr : worker_thread+0x1bc/0x360
Call trace:
process_one_work+0x110/0x680 (P)
worker_thread+0x1bc/0x360 (L)
worker_thread+0x1bc/0x360
kthread+0x100/0x118
ret_from_fork+0x10/0x20
Code: f84086a1 f9000fe1 53041c21 b9003361 (f9400661)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Oops: Fatal exception
SMP: stopping secondary CPUs
SMP: failed to stop secondary CPUs 2-3
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: 0x275bb9540000 from 0xffff800080000000
PHYS_OFFSET: 0xffff8fbba0000000
CPU features: 0x100,00000070,00801250,8201720b
[CAUSE]
The above warning is triggered immediately after the delalloc range
failure, this happens in the following sequence:
- Range [1568K, 1636K) is dirty
1536K 1568K 1600K 1636K 1664K
| |/////////|////////| |
Where 1536K, 1600K and 1664K are page boundaries (64K page size)
- Enter extent_writepage() for page 1536K
- Enter run_delalloc_nocow() with locke
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
smb: client: Add check for next_buffer in receive_encrypted_standard()
Add check for the return value of cifs_buf_get() and cifs_small_buf_get()
in receive_encrypted_standard() to prevent null pointer dereference.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
acct: perform last write from workqueue
In [1] it was reported that the acct(2) system call can be used to
trigger NULL deref in cases where it is set to write to a file that
triggers an internal lookup. This can e.g., happen when pointing acc(2)
to /sys/power/resume. At the point the where the write to this file
happens the calling task has already exited and called exit_fs(). A
lookup will thus trigger a NULL-deref when accessing current->fs.
Reorganize the code so that the the final write happens from the
workqueue but with the caller's credentials. This preserves the
(strange) permission model and has almost no regression risk.
This api should stop to exist though.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-12
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_midi: fix MIDI Streaming descriptor lengths
While the MIDI jacks are configured correctly, and the MIDIStreaming
endpoint descriptors are filled with the correct information,
bNumEmbMIDIJack and bLength are set incorrectly in these descriptors.
This does not matter when the numbers of in and out ports are equal, but
when they differ the host will receive broken descriptors with
uninitialized stack memory leaking into the descriptor for whichever
value is smaller.
The precise meaning of "in" and "out" in the port counts is not clearly
defined and can be confusing. But elsewhere the driver consistently
uses this to match the USB meaning of IN and OUT viewed from the host,
so that "in" ports send data to the host and "out" ports receive data
from it.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: reallocate buf lists on upgrade
IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: core: flush gadget workqueue after device removal
device_del() can lead to new work being scheduled in gadget->work
workqueue. This is observed, for example, with the dwc3 driver with the
following call stack:
device_del()
gadget_unbind_driver()
usb_gadget_disconnect_locked()
dwc3_gadget_pullup()
dwc3_gadget_soft_disconnect()
usb_gadget_set_state()
schedule_work(&gadget->work)
Move flush_work() after device_del() to ensure the workqueue is cleaned
up.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-07
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
Move the conditional loading of hardware DR6 with the guest's DR6 value
out of the core .vcpu_run() loop to fix a bug where KVM can load hardware
with a stale vcpu->arch.dr6.
When the guest accesses a DR and host userspace isn't debugging the guest,
KVM disables DR interception and loads the guest's values into hardware on
VM-Enter and saves them on VM-Exit. This allows the guest to access DRs
at will, e.g. so that a sequence of DR accesses to configure a breakpoint
only generates one VM-Exit.
For DR0-DR3, the logic/behavior is identical between VMX and SVM, and also
identical between KVM_DEBUGREG_BP_ENABLED (userspace debugging the guest)
and KVM_DEBUGREG_WONT_EXIT (guest using DRs), and so KVM handles loading
DR0-DR3 in common code, _outside_ of the core kvm_x86_ops.vcpu_run() loop.
But for DR6, the guest's value doesn't need to be loaded into hardware for
KVM_DEBUGREG_BP_ENABLED, and SVM provides a dedicated VMCB field whereas
VMX requires software to manually load the guest value, and so loading the
guest's value into DR6 is handled by {svm,vmx}_vcpu_run(), i.e. is done
_inside_ the core run loop.
Unfortunately, saving the guest values on VM-Exit is initiated by common
x86, again outside of the core run loop. If the guest modifies DR6 (in
hardware, when DR interception is disabled), and then the next VM-Exit is
a fastpath VM-Exit, KVM will reload hardware DR6 with vcpu->arch.dr6 and
clobber the guest's actual value.
The bug shows up primarily with nested VMX because KVM handles the VMX
preemption timer in the fastpath, and the window between hardware DR6
being modified (in guest context) and DR6 being read by guest software is
orders of magnitude larger in a nested setup. E.g. in non-nested, the
VMX preemption timer would need to fire precisely between #DB injection
and the #DB handler's read of DR6, whereas with a KVM-on-KVM setup, the
window where hardware DR6 is "dirty" extends all the way from L1 writing
DR6 to VMRESUME (in L1).
L1's view:
==========
<L1 disables DR interception>
CPU 0/KVM-7289 [023] d.... 2925.640961: kvm_entry: vcpu 0
A: L1 Writes DR6
CPU 0/KVM-7289 [023] d.... 2925.640963: <hack>: Set DRs, DR6 = 0xffff0ff1
B: CPU 0/KVM-7289 [023] d.... 2925.640967: kvm_exit: vcpu 0 reason EXTERNAL_INTERRUPT intr_info 0x800000ec
D: L1 reads DR6, arch.dr6 = 0
CPU 0/KVM-7289 [023] d.... 2925.640969: <hack>: Sync DRs, DR6 = 0xffff0ff0
CPU 0/KVM-7289 [023] d.... 2925.640976: kvm_entry: vcpu 0
L2 reads DR6, L1 disables DR interception
CPU 0/KVM-7289 [023] d.... 2925.640980: kvm_exit: vcpu 0 reason DR_ACCESS info1 0x0000000000000216
CPU 0/KVM-7289 [023] d.... 2925.640983: kvm_entry: vcpu 0
CPU 0/KVM-7289 [023] d.... 2925.640983: <hack>: Set DRs, DR6 = 0xffff0ff0
L2 detects failure
CPU 0/KVM-7289 [023] d.... 2925.640987: kvm_exit: vcpu 0 reason HLT
L1 reads DR6 (confirms failure)
CPU 0/KVM-7289 [023] d.... 2925.640990: <hack>: Sync DRs, DR6 = 0xffff0ff0
L0's view:
==========
L2 reads DR6, arch.dr6 = 0
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_exit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
L2 => L1 nested VM-Exit
CPU 23/KVM-5046 [001] ..... 3410.005610: kvm_nested_vmexit_inject: reason: DR_ACCESS ext_inf1: 0x0000000000000216
CPU 23/KVM-5046 [001] d.... 3410.005610: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_exit: vcpu 23 reason VMREAD
CPU 23/KVM-5046 [001] d.... 3410.005611: kvm_entry: vcpu 23
CPU 23/KVM-5046 [001] d.... 3410.
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-07