Linux: >> Linux Kernel >> 6.17.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
i2c: i801: fix hardware state machine corruption in error path
A severe livelock and subsequent Hung Task panic were observed in the
i2c-i801 driver during concurrent Fuzzing. The crash is caused by an
unconditional hardware register cleanup in the error handling path of
i801_access().
When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus
controller is actively used by BIOS/ACPI), the kernel does not actually
acquire the hardware ownership. However, the code jumps to the 'out'
label and executes:
iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv));
This forcefully clears the INUSE_STS lock and resets the hardware status
flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI
transactions and totally corrupts the SMBus hardware state machine.
Consequently, all subsequent i801_access() calls fail at the pre-check
stage, triggering an endless stream of "SMBus is busy, can't use it!"
error logs. Over a slow serial console, this printk flood monopolizes
the CPU (Console Livelock), starving other processes trying to acquire
the mmap_lock down_read semaphore, ultimately triggering the hung task
watchdog.
Fix this by moving the 'out' label below the hardware register cleanup.
If i801_check_pre() fails, we safely bypass the iowrite8() and only
release the software locks (pm_runtime and mutex), strictly adhering to
the rule of not releasing resources that were never acquired.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock
l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for
pending_rx_work. process_pending_rx() takes the same mutex, so teardown
can deadlock against the worker it is flushing.
This issue was found by our static analysis tool and then manually
reviewed against the current tree.
The grounded PoC kept the l2cap_conn_ready() -> queue_work(...,
&conn->pending_rx_work) submit path, the l2cap_conn_del() ->
cancel_work_sync(&conn->pending_rx_work) teardown path, and the
process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep
WARNING: possible circular locking dependency detected
process_pending_rx+0x21/0x2a [vuln_msv]
l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv]
*** DEADLOCK ***
Cancel pending_rx_work before taking conn->lock, matching the existing
lock-before-drain ordering used for the two delayed works in the same
teardown path. The pending_rx queue is still purged after the work has
been cancelled and conn->lock has been acquired.
CVSS Score
8.8
EPSS Score
0.003
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
net/sched: dualpi2: fix GSO backlog accounting
When DualPI2 splits a GSO skb into N segments, it propagates N
additional packets to its parent before returning NET_XMIT_SUCCESS.
The parent then accounts for the original skb once more, leaving its
qlen one larger than the number of packets actually queued.
With QFQ as the parent, after all real packets are dequeued, QFQ still
has a non-zero qlen while its in-service aggregate has no active
classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes
the result to qfq_peek_skb(), causing a NULL pointer dereference.
Follow the same pattern used by tbf_segment() and taprio: count only
successfully queued segments, propagate the difference between the
original skb and those segments, and return NET_XMIT_SUCCESS whenever
at least one segment was queued.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
xfs: fail recovery on a committed log item with no regions
If the first op of a transaction is a bare transaction header
(len == sizeof(struct xfs_trans_header)), xlog_recover_add_to_trans()
adds an item but no region, leaving it on r_itemq with ri_cnt == 0 and
ri_buf == NULL.
The header can be split across op records, so later ops may still add
regions; the item is only invalid if the transaction commits with none.
The runtime commit path never emits such a transaction, so this only
happens on a crafted log. It came from an AI-assisted code audit of the
recovery parser.
xlog_recover_reorder_trans() calls ITEM_TYPE() on the item, which reads
*(unsigned short *)item->ri_buf[0].iov_base and faults on the NULL
ri_buf. Reject it there, before the commit handlers that also read
ri_buf[0].
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:xlog_recover_reorder_trans (fs/xfs/xfs_log_recover.c:1836)
xlog_recover_commit_trans (fs/xfs/xfs_log_recover.c:2043)
xlog_recover_process_data (fs/xfs/xfs_log_recover.c:2501)
xlog_do_recovery_pass (fs/xfs/xfs_log_recover.c:3244)
xlog_recover (fs/xfs/xfs_log_recover.c:3493)
xfs_log_mount (fs/xfs/xfs_log.c:618)
xfs_mountfs (fs/xfs/xfs_mount.c:1034)
xfs_fs_fill_super (fs/xfs/xfs_super.c:1938)
vfs_get_tree (fs/super.c:1695)
path_mount (fs/namespace.c:4161)
__x64_sys_mount (fs/namespace.c:4367)
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()
rmnet_dellink() removes the endpoint from the hash table with
hlist_del_init_rcu() and then immediately frees it with kfree(). However,
RCU readers on the receive path (rmnet_rx_handler ->
__rmnet_map_ingress_handler) may still hold a reference to the endpoint and
dereference ep->egress_dev after the memory has been freed. The endpoint is
a kmalloc-32 object, and the stale read at offset 8 corresponds to the
egress_dev pointer.
BUG: unable to handle page fault for address: ffffffffde942eef
Oops: 0002 [#1] SMP NOPTI
CPU: 1 UID: 0 PID: 137 Comm: poc_write Not tainted 7.0.0+ #4 PREEMPTLAZY
RIP: 0010:rmnet_vnd_rx_fixup (rmnet_vnd.c:27)
Call Trace:
<TASK>
__rmnet_map_ingress_handler (rmnet_handlers.c:48 rmnet_handlers.c:101)
rmnet_rx_handler (rmnet_handlers.c:129 rmnet_handlers.c:235)
__netif_receive_skb_core.constprop.0 (net/core/dev.c:6096)
__netif_receive_skb_one_core (net/core/dev.c:6208)
netif_receive_skb (net/core/dev.c:6467)
tun_get_user (drivers/net/tun.c:1955)
tun_chr_write_iter (drivers/net/tun.c:2003)
vfs_write (fs/read_write.c:688)
ksys_write (fs/read_write.c:740)
</TASK>
Add an rcu_head field to struct rmnet_endpoint and replace kfree() with
kfree_rcu() so the endpoint memory remains valid through the RCU grace
period. Also remove the rmnet_vnd_dellink() call and inline only the
nr_rmnet_devs decrement, since rmnet_vnd_dellink() would set
ep->egress_dev to NULL during the grace period, creating a data race
with lockless readers.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: fix race between dump and ip_set_list resize
The release path of ip_set_dump_do() and ip_set_dump_done() read
inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw()
of the array pointer. These run from netlink_recvmsg() without the nfnl
mutex and without an RCU read-side critical section.
A concurrent ip_set_create() can grow the array: it publishes the new
array, calls synchronize_net() and then kvfree()s the old one. Since the
dump paths read the array outside any RCU reader, synchronize_net() does
not wait for them and the old array can be freed while they still index
into it, causing a use-after-free.
The dumped set itself stays pinned via set->ref_netlink, so only the
array load needs protecting. Take rcu_read_lock() around it, matching
ip_set_get_byname() and __ip_set_put_byindex().
BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
Read of size 8 at addr ffff88800b5c4018 by task exploit/150
Call Trace:
...
kasan_report (mm/kasan/report.c:595)
ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
netlink_dump (net/netlink/af_netlink.c:2325)
netlink_recvmsg (net/netlink/af_netlink.c:1976)
sock_recvmsg (net/socket.c:1159)
__sys_recvfrom (net/socket.c:2315)
...
Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7]
RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698)
Kernel panic - not syncing: Fatal exception
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-20
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs
In iommu_mmio_write() and iommu_capability_write(), the variables
dbg_mmio_offset and dbg_cap_offset are declared as int. However, they
are populated using kstrtou32_from_user(). If a user provides a
sufficiently large value, it can become a negative integer.
Prior to this patch, the AMD IOMMU debugfs implementation was already
protected by different mechanisms.
1. #define OFS_IN_SZ 8 ensures the user string <= 8 bytes, so
e.g. 0xffffffff isn't a valid input.
if (cnt > OFS_IN_SZ)
return -EINVAL;
2. Implicit type promotion in iommu_mmio_write(), dbg_mmio_offset is int
and iommu->mmio_phys_end is u64
if (dbg_mmio_offset > iommu->mmio_phys_end - sizeof(u64))
return -EINVAL;
3. The show handlers would currently catch the negative number and
refuse to perform the read.
Replace kstrtou32_from_user() with kstrtos32_from_user() to parse the
input, and check for negative values to explicitly prevent out-of-bounds
memory accesses directly in iommu_mmio_write() and
iommu_capability_write().
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: bnep: Fix UAF read of dev->name
bnep_add_connection() needs to keep holding the bnep_session_sem while
reading dev->name (just like bnep_get_connlist() does); otherwise the
bnep_session() thread can concurrently free the net_device, which can for
example be triggered by a concurrent bnep_del_connection().
(This UAF is fairly uninteresting from a security perspective;
calling bnep_add_connection() requires passing a capable(CAP_NET_ADMIN)
check. It also requires completely tearing down a netdev during a fairly
tight race window.)
CVSS Score
8.8
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
net: wwan: iosm: fix potential memory leaks in ipc_imem_init()
The memory allocated in ipc_protocol_init() is not freed on the error
paths that follow in ipc_imem_init(). Fix that by calling the
corresponding release function ipc_protocol_deinit() in the error path.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
mm/memory_hotplug: fix memory block reference leak on remove
Patch series "mm: Fix memory block leaks and locking", v2.
This series fixes two memory block device reference leaks and one locking
issue around the per-memory_block hwpoison counter.
This patch (of 2):
remove_memory_blocks_and_altmaps() looks up each memory block with
find_memory_block(), which acquires a reference to the memory block
device.
That reference is never dropped on this path, resulting in a leaked device
reference when removing memory blocks and their altmaps. Drop the
reference after retrieving mem->altmap and clearing mem->altmap, before
removing the memory block device.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19