Linux: >> Linux Kernel >> 6.6.144 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: fix use-after-free bugs in mt7996_mac_dump_work()
When the mt7996 pci chip is detaching, the mt7996_crash_data is
released in mt7996_coredump_unregister(). However, the work item
dump_work may still be running or pending, leading to UAF bugs
when the already freed crash_data is dereferenced again in
mt7996_mac_dump_work().
The race condition can occur as follows:
CPU 0 (removal path) | CPU 1 (workqueue)
mt7996_pci_remove() | mt7996_sys_recovery_set()
mt7996_unregister_device() | mt7996_reset()
mt7996_coredump_unregister() | queue_work()
vfree(dev->coredump.crash_data) | mt7996_mac_dump_work()
| crash_data-> // UAF
Fix this by ensuring dump_work is properly canceled before
the crash_data is deallocated. Add cancel_work_sync() in
mt7996_unregister_device() to synchronize with any pending
or executing dump work.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops
When a BPF sock_ops program accesses ctx fields with dst_reg == src_reg,
the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the
destination register in the !fullsock / !locked_tcp_sock path.
Both macros borrow a temporary register to check is_fullsock /
is_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the
ctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with
a request_sock), dst_reg should be zeroed but is not, leaving the stale
ctx pointer:
- SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks
as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer,
leading to stack-out-of-bounds access in helpers like
bpf_skc_to_tcp6_sock().
- SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the
verifier believes is a SCALAR_VALUE, leaking a kernel pointer.
Fix both macros by:
- Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the
added instruction.
- Adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register
restore in the !fullsock path, placed after the restore because
dst_reg == src_reg means we need src_reg intact to read ctx->temp.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
sctp: disable BH before calling udp_tunnel_xmit_skb()
udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with
BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to
tunnel xmit functions"), on the path:
udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit()
dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU.
Without local_bh_disable(), the context may move between CPUs, which can
break the inc/dec pairing. This may lead to incorrect recursion level
detection and cause packets to be dropped in ip(6)_tunnel_xmit() or
__dev_queue_xmit().
Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths.
In my testing, after enabling the SCTP over UDP:
# ip net exec ha sysctl -w net.sctp.udp_port=9899
# ip net exec ha sysctl -w net.sctp.encap_port=9899
# ip net exec hb sysctl -w net.sctp.udp_port=9899
# ip net exec hb sysctl -w net.sctp.encap_port=9899
# ip net exec ha iperf3 -s
- without this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender
[ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver
- with this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver
CVSS Score
7.5
EPSS Score
0.003
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix clone_alias() to use the original device's devid
Currently clone_alias() assumes first argument (pdev) is always the
original device pointer. This function is called by
pci_for_each_dma_alias() which based on topology decides to send
original or alias device details in first argument.
This meant that the source devid used to look up and copy the DTE
may be incorrect, leading to wrong or stale DTE entries being
propagated to alias device.
Fix this by passing the original pdev as the opaque data argument to
both the direct clone_alias() call and pci_for_each_dma_alias(). Inside
clone_alias(), retrieve the original device from data and compute devid
from it.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked()
When a compressed or sparse attribute has its clusters frame-aligned,
vcn is rounded down to the frame start using cmask, which can result
in vcn != vcn0. In this case, vcn and vcn0 may reside in different
attribute segments.
The code already handles the case where vcn is in a different segment
by loading its runs before allocation. However, it fails to load runs
for vcn0 when vcn0 resides in a different segment than vcn. This causes
run_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was
never loaded into the in-memory run list, triggering the WARN_ON(1).
Fix this by adding a missing check for vcn0 after the existing vcn
segment check. If vcn0 falls outside the current segment range
[svcn, evcn1), find and load the attribute segment containing vcn0
before performing the run lookup.
The following scenario triggers the bug:
attr_data_get_block_locked()
vcn = vcn0 & cmask <- vcn != vcn0 after frame alignment
load runs for vcn segment <- vcn0 segment not loaded!
attr_allocate_clusters() <- allocation succeeds
run_lookup_entry(vcn0) <- vcn0 not in run -> SPARSE_LCN
WARN_ON(1) <- bug fires here!
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix data loss caused by incorrect use of nat_entry flag
Data loss can occur when fsync is performed on a newly created file
(before any checkpoint has been written) concurrently with a checkpoint
operation. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_flush_nat_entries
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return false
SPO and lost 'file A'
f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC
flags for the nat_entry, but this does not mean that the checkpoint has
actually completed successfully. However, f2fs_need_inode_block_update()
checks these flags and incorrectly assumes that the checkpoint has
finished.
The root cause is that the semantics of IS_CHECKPOINTED and
HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully
completes.
This patch modifies f2fs_need_inode_block_update() to acquire the
sbi->node_write lock before reading the nat_entry flags, ensuring that
once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the
checkpoint operation has already completed.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
f2fs: avoid reading already updated pages during GC
We found the following issue during fuzz testing:
page: refcount:3 mapcount:0 mapping:00000000b6e89c65 index:0x18b2dc pfn:0x161ba9
memcg:f8ffff800e269c00
aops:f2fs_meta_aops ino:2
flags: 0x52880000000080a9(locked|waiters|uptodate|lru|private|zone=1|kasantag=0x4a)
raw: 52880000000080a9 fffffffec6e17588 fffffffec0ccc088 a7ffff8067063618
raw: 000000000018b2dc 0000000000000009 00000003ffffffff f8ffff800e269c00
page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate(folio))
page_owner tracks the page as allocated
post_alloc_hook+0x58c/0x5ec
prep_new_page+0x34/0x284
get_page_from_freelist+0x2dcc/0x2e8c
__alloc_pages_noprof+0x280/0x76c
__folio_alloc_noprof+0x18/0xac
__filemap_get_folio+0x6bc/0xdc4
pagecache_get_page+0x3c/0x104
do_garbage_collect+0x5c78/0x77a4
f2fs_gc+0xd74/0x25f0
gc_thread_func+0xb28/0x2930
kthread+0x464/0x5d8
ret_from_fork+0x10/0x20
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1563!
folio_end_read+0x140/0x168
f2fs_finish_read_bio+0x5c4/0xb80
f2fs_read_end_io+0x64c/0x708
bio_endio+0x85c/0x8c0
blk_update_request+0x690/0x127c
scsi_end_request+0x9c/0xb8c
scsi_io_completion+0xf0/0x250
scsi_finish_command+0x430/0x45c
scsi_complete+0x178/0x6d4
blk_mq_complete_request+0xcc/0x104
scsi_done_internal+0x214/0x454
scsi_done+0x24/0x34
which is similar to the problem reported by syzbot:
https://syzkaller.appspot.com/bug?extid=3686758660f980b402dc
This case is consistent with the description in commit 9bf1a3f
("f2fs: avoid GC causing encrypted file corrupted"):
Page 1 is moved from blkaddr A to blkaddr B by move_data_block, and after
being written it is marked as uptodate. Then, Page 1 is moved from blkaddr
B to blkaddr C, VM_BUG_ON_FOLIO was triggered in the endio initiated by
ra_data_block.
There is no need to read Page 1 again from blkaddr B, since it has already
been updated. Therefore, avoid initiating I/O in this case.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free if write is called after disconnect
If a user writes to the chardev after disconnect has been called, the
kernel panics with the following trace (with
CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
BUG: kernel NULL pointer dereference, address: 0000000000000218
...
Call Trace:
<TASK>
gb_operation_create_common+0x61/0x180
gb_operation_create_flags+0x28/0xa0
gb_operation_sync_timeout+0x6f/0x100
raw_write+0x7b/0xc7 [gb_raw]
vfs_write+0xcf/0x420
? task_mm_cid_work+0x136/0x220
ksys_write+0x63/0xe0
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Disconnect calls gb_connection_destroy, which ends up freeing the
connection object. When gb_operation_sync is called in the write file
operations, its gets a freed connection as parameter and the kernel
panics.
The gb_connection_destroy cannot be moved out of the disconnect
function, as the Greybus subsystem expect all connections belonging to a
bundle to be destroyed when disconnect returns.
To prevent this bug, use a rw lock to synchronize access between write
and disconnect. This guarantees that the write function doesn't try
to use a disconnected connection.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free on cdev close
This addresses a use-after-free bug when a raw bundle is disconnected
but its chardev is still opened by an application. When the application
releases the cdev, it causes the following panic when init on free is
enabled (CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 139 at lib/refcount.c:28 refcount_warn_saturate+0xd0/0x130
...
Call Trace:
<TASK>
cdev_put+0x18/0x30
__fput+0x255/0x2a0
__x64_sys_close+0x3d/0x80
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The cdev is contained in the "gb_raw" structure, which is freed in the
disconnect operation. When the cdev is released at a later time,
cdev_put gets an address that points to freed memory.
To fix this use-after-free, convert the struct device from a pointer to
being embedded, that makes the lifetime of the cdev and of this device
the same. Then, use cdev_device_add, which guarantees that the device
won't be released until all references to the cdev have been released.
Finally, delegate the freeing of the structure to the device release
function, instead of freeing immediately in the disconnect callback.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ice: fix double-free of tx_buf skb
If ice_tso() or ice_tx_csum() fail, the error path in
ice_xmit_frame_ring() frees the skb, but the 'first' tx_buf still points
to it and is marked as valid (ICE_TX_BUF_SKB).
'next_to_use' remains unchanged, so the potential problem will
likely fix itself when the next packet is transmitted and the tx_buf
gets overwritten. But if there is no next packet and the interface is
brought down instead, ice_clean_tx_ring() -> ice_unmap_and_free_tx_buf()
will find the tx_buf and free the skb for the second time.
The fix is to reset the tx_buf type to ICE_TX_BUF_EMPTY in the error
path, so that ice_unmap_and_free_tx_buf().
Move the initialization of 'first' up, to ensure it's already valid in
case we hit the linearization error path.
The bug was spotted by AI while I had it looking for something else.
It also proposed an initial version of the patch.
I reproduced the bug and tested the fix by adding code to inject
failures, on a build with KASAN.
I looked for similar bugs in related Intel drivers and did not find any.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24