Linux: >> Linux Kernel >> 6.6.48 Security Vulnerabilities
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.
CVSS Score
7.8
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:
wifi: at76c50x: fix use after free access in at76_disconnect
The memory pointed to by priv is freed at the end of at76_delete_device
function (using ieee80211_free_hw). But the code then accesses the udev
field of the freed object to put the USB device. This may also lead to a
memory leak of the usb device. Fix this by using udev from interface.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered
Russell King reports that a system with mv88e6xxx dereferences a NULL
pointer when unbinding this driver:
https://lore.kernel.org/netdev/Z_lRkMlTJ1KQ0kVX@shell.armlinux.org.uk/
The crash seems to be in devlink_region_destroy(), which is not NULL
tolerant but is given a NULL devlink global region pointer.
At least on some chips, some devlink regions are conditionally registered
since the blamed commit, see mv88e6xxx_setup_devlink_regions_global():
if (cond && !cond(chip))
continue;
These are MV88E6XXX_REGION_STU and MV88E6XXX_REGION_PVT. If the chip
does not have an STU or PVT, it should crash like this.
To fix the issue, avoid unregistering those regions which are NULL, i.e.
were skipped at mv88e6xxx_setup_devlink_regions_global() time.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
cxgb4: fix memory leak in cxgb4_init_ethtool_filters() error path
In the for loop used to allocate the loc_array and bmap for each port, a
memory leak is possible when the allocation for loc_array succeeds,
but the allocation for bmap fails. This is because when the control flow
goes to the label free_eth_finfo, only the allocations starting from
(i-1)th iteration are freed.
Fix that by freeing the loc_array in the bmap allocation error path.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix nested key length validation in the set() action
It's not safe to access nla_len(ovs_key) if the data is smaller than
the netlink header. Check that the attribute is OK first.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
net: mctp: Set SOCK_RCU_FREE
Bind lookup runs under RCU, so ensure that a socket doesn't go away in
the middle of a lookup.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btrtl: Prevent potential NULL dereference
The btrtl_initialize() function checks that rtl_load_file() either
had an error or it loaded a zero length file. However, if it loaded
a zero length file then the error code is not set correctly. It
results in an error pointer vs NULL bug, followed by a NULL pointer
dereference. This was detected by Smatch:
drivers/bluetooth/btrtl.c:592 btrtl_initialize() warn: passing zero to 'ERR_PTR'
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: avs: Fix null-ptr-deref in avs_component_probe()
devm_kasprintf() returns NULL when memory allocation fails. Currently,
avs_component_probe() does not check for this case, which results in a
NULL pointer dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Purge vif txq in ieee80211_do_stop()
After ieee80211_do_stop() SKB from vif's txq could still be processed.
Indeed another concurrent vif schedule_and_wake_txq call could cause
those packets to be dequeued (see ieee80211_handle_wake_tx_queue())
without checking the sdata current state.
Because vif.drv_priv is now cleared in this function, this could lead to
driver crash.
For example in ath12k, ahvif is store in vif.drv_priv. Thus if
ath12k_mac_op_tx() is called after ieee80211_do_stop(), ahvif->ah can be
NULL, leading the ath12k_warn(ahvif->ah,...) call in this function to
trigger the NULL deref below.
Unable to handle kernel paging request at virtual address dfffffc000000001
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
batman_adv: bat0: Interface deactivated: brbh1337
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfffffc000000001] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] SMP
CPU: 1 UID: 0 PID: 978 Comm: lbd Not tainted 6.13.0-g633f875b8f1e #114
Hardware name: HW (DT)
pstate: 10000005 (nzcV daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ath12k_mac_op_tx+0x6cc/0x29b8 [ath12k]
lr : ath12k_mac_op_tx+0x174/0x29b8 [ath12k]
sp : ffffffc086ace450
x29: ffffffc086ace450 x28: 0000000000000000 x27: 1ffffff810d59ca4
x26: ffffff801d05f7c0 x25: 0000000000000000 x24: 000000004000001e
x23: ffffff8009ce4926 x22: ffffff801f9c0800 x21: ffffff801d05f7f0
x20: ffffff8034a19f40 x19: 0000000000000000 x18: ffffff801f9c0958
x17: ffffff800bc0a504 x16: dfffffc000000000 x15: ffffffc086ace4f8
x14: ffffff801d05f83c x13: 0000000000000000 x12: ffffffb003a0bf03
x11: 0000000000000000 x10: ffffffb003a0bf02 x9 : ffffff8034a19f40
x8 : ffffff801d05f818 x7 : 1ffffff0069433dc x6 : ffffff8034a19ee0
x5 : ffffff801d05f7f0 x4 : 0000000000000000 x3 : 0000000000000001
x2 : 0000000000000000 x1 : dfffffc000000000 x0 : 0000000000000008
Call trace:
ath12k_mac_op_tx+0x6cc/0x29b8 [ath12k] (P)
ieee80211_handle_wake_tx_queue+0x16c/0x260
ieee80211_queue_skb+0xeec/0x1d20
ieee80211_tx+0x200/0x2c8
ieee80211_xmit+0x22c/0x338
__ieee80211_subif_start_xmit+0x7e8/0xc60
ieee80211_subif_start_xmit+0xc4/0xee0
__ieee80211_subif_start_xmit_8023.isra.0+0x854/0x17a0
ieee80211_subif_start_xmit_8023+0x124/0x488
dev_hard_start_xmit+0x160/0x5a8
__dev_queue_xmit+0x6f8/0x3120
br_dev_queue_push_xmit+0x120/0x4a8
__br_forward+0xe4/0x2b0
deliver_clone+0x5c/0xd0
br_flood+0x398/0x580
br_dev_xmit+0x454/0x9f8
dev_hard_start_xmit+0x160/0x5a8
__dev_queue_xmit+0x6f8/0x3120
ip6_finish_output2+0xc28/0x1b60
__ip6_finish_output+0x38c/0x638
ip6_output+0x1b4/0x338
ip6_local_out+0x7c/0xa8
ip6_send_skb+0x7c/0x1b0
ip6_push_pending_frames+0x94/0xd0
rawv6_sendmsg+0x1a98/0x2898
inet_sendmsg+0x94/0xe0
__sys_sendto+0x1e4/0x308
__arm64_sys_sendto+0xc4/0x140
do_el0_svc+0x110/0x280
el0_svc+0x20/0x60
el0t_64_sync_handler+0x104/0x138
el0t_64_sync+0x154/0x158
To avoid that, empty vif's txq at ieee80211_do_stop() so no packet could
be dequeued after ieee80211_do_stop() (new packets cannot be queued
because SDATA_STATE_RUNNING is cleared at this point).
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01