Linux: >> Linux Kernel >> 4.4.244 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_fq: fix integer overflow of "credit"
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: Avoid nf_ct_helper_hash uses after free
If nf_conntrack_init_start() fails (for example due to a
register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini()
clean-up path frees the nf_ct_helper_hash map.
When built with NF_CONNTRACK=y, further netfilter modules (e.g:
netfilter_conntrack_ftp) can still be loaded and call
nf_conntrack_helpers_register(), independently of whether nf_conntrack
initialized correctly. This accesses the nf_ct_helper_hash dangling
pointer and causes a uaf, possibly leading to random memory corruption.
This patch guards nf_conntrack_helper_register() from accessing a freed
or uninitialized nf_ct_helper_hash pointer and fixes possible
uses-after-free when loading a conntrack module.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
md: fix soft lockup in status_resync
status_resync() will calculate 'curr_resync - recovery_active' to show
user a progress bar like following:
[============>........] resync = 61.4%
'curr_resync' and 'recovery_active' is updated in md_do_sync(), and
status_resync() can read them concurrently, hence it's possible that
'curr_resync - recovery_active' can overflow to a huge number. In this
case status_resync() will be stuck in the loop to print a large amount
of '=', which will end up soft lockup.
Fix the problem by setting 'resync' to MD_RESYNC_ACTIVE in this case,
this way resync in progress will be reported to user.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix possible data races in gfs2_show_options()
Some fields such as gt_logd_secs of the struct gfs2_tune are accessed
without holding the lock gt_spin in gfs2_show_options():
val = sdp->sd_tune.gt_logd_secs;
if (val != 30)
seq_printf(s, ",commit=%d", val);
And thus can cause data races when gfs2_show_options() and other functions
such as gfs2_reconfigure() are concurrently executed:
spin_lock(>->gt_spin);
gt->gt_logd_secs = newargs->ar_commit;
To fix these possible data races, the lock sdp->sd_tune.gt_spin is
acquired before accessing the fields of gfs2_tune and released after these
accesses.
Further changes by Andreas:
- Don't hold the spin lock over the seq_printf operations.
CVSS Score
7.0
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
media: solo6x10: fix possible memory leak in solo_sysfs_init()
If device_register() returns error in solo_sysfs_init(), the
name allocated by dev_set_name() need be freed. As comment of
device_register() says, it should use put_device() to give up
the reference in the error path. So fix this by calling
put_device(), then the name can be freed in kobject_cleanup().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata
Following concurrent processes:
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
super_cache_scan
prune_icache_sb
dispose_list
evict
ext4_evict_inode
ext4_clear_inode
ext4_discard_preallocations
ext4_mb_load_buddy_gfp
ext4_mb_init_cache
ext4_read_block_bitmap_nowait
ext4_read_bh_nowait
submit_bh
dm_submit_bio
do_worker
process_deferred_bios
commit
metadata_operation_failed
dm_pool_abort_metadata
down_write(&pmd->root_lock) - LOCK B
__destroy_persistent_data_objects
dm_block_manager_destroy
dm_bufio_client_destroy
unregister_shrinker
down_write(&shrinker_rwsem)
thin_map |
dm_thin_find_block ↓
down_read(&pmd->root_lock) --> ABBA deadlock
, which triggers hung task:
[ 76.974820] INFO: task kworker/u4:3:63 blocked for more than 15 seconds.
[ 76.976019] Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910
[ 76.978521] task:kworker/u4:3 state:D stack:0 pid:63 ppid:2
[ 76.978534] Workqueue: dm-thin do_worker
[ 76.978552] Call Trace:
[ 76.978564] __schedule+0x6ba/0x10f0
[ 76.978582] schedule+0x9d/0x1e0
[ 76.978588] rwsem_down_write_slowpath+0x587/0xdf0
[ 76.978600] down_write+0xec/0x110
[ 76.978607] unregister_shrinker+0x2c/0xf0
[ 76.978616] dm_bufio_client_destroy+0x116/0x3d0
[ 76.978625] dm_block_manager_destroy+0x19/0x40
[ 76.978629] __destroy_persistent_data_objects+0x5e/0x70
[ 76.978636] dm_pool_abort_metadata+0x8e/0x100
[ 76.978643] metadata_operation_failed+0x86/0x110
[ 76.978649] commit+0x6a/0x230
[ 76.978655] do_worker+0xc6e/0xd90
[ 76.978702] process_one_work+0x269/0x630
[ 76.978714] worker_thread+0x266/0x630
[ 76.978730] kthread+0x151/0x1b0
[ 76.978772] INFO: task test.sh:2646 blocked for more than 15 seconds.
[ 76.979756] Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910
[ 76.982111] task:test.sh state:D stack:0 pid:2646 ppid:2459
[ 76.982128] Call Trace:
[ 76.982139] __schedule+0x6ba/0x10f0
[ 76.982155] schedule+0x9d/0x1e0
[ 76.982159] rwsem_down_read_slowpath+0x4f4/0x910
[ 76.982173] down_read+0x84/0x170
[ 76.982177] dm_thin_find_block+0x4c/0xd0
[ 76.982183] thin_map+0x201/0x3d0
[ 76.982188] __map_bio+0x5b/0x350
[ 76.982195] dm_submit_bio+0x2b6/0x930
[ 76.982202] __submit_bio+0x123/0x2d0
[ 76.982209] submit_bio_noacct_nocheck+0x101/0x3e0
[ 76.982222] submit_bio_noacct+0x389/0x770
[ 76.982227] submit_bio+0x50/0xc0
[ 76.982232] submit_bh_wbc+0x15e/0x230
[ 76.982238] submit_bh+0x14/0x20
[ 76.982241] ext4_read_bh_nowait+0xc5/0x130
[ 76.982247] ext4_read_block_bitmap_nowait+0x340/0xc60
[ 76.982254] ext4_mb_init_cache+0x1ce/0xdc0
[ 76.982259] ext4_mb_load_buddy_gfp+0x987/0xfa0
[ 76.982263] ext4_discard_preallocations+0x45d/0x830
[ 76.982274] ext4_clear_inode+0x48/0xf0
[ 76.982280] ext4_evict_inode+0xcf/0xc70
[ 76.982285] evict+0x119/0x2b0
[ 76.982290] dispose_list+0x43/0xa0
[ 76.982294] prune_icache_sb+0x64/0x90
[ 76.982298] super_cache_scan+0x155/0x210
[ 76.982303] do_shrink_slab+0x19e/0x4e0
[ 76.982310] shrink_slab+0x2bd/0x450
[ 76.982317] drop_slab+0xcc/0x1a0
[ 76.982323] drop_caches_sysctl_handler+0xb7/0xe0
[ 76.982327] proc_sys_call_handler+0x1bc/0x300
[ 76.982331] proc_sys_write+0x17/0x20
[ 76.982334] vfs_write+0x3d3/0x570
[ 76.982342] ksys_write+0x73/0x160
[ 76.982347] __x64_sys_write+0x1e/0x30
[ 76.982352] do_syscall_64+0x35/0x80
[ 76.982357] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Funct
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: omap4-common: Fix refcount leak bug
In omap4_sram_init(), of_find_compatible_node() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
media: si470x: Fix use-after-free in si470x_int_in_callback()
syzbot reported use-after-free in si470x_int_in_callback() [1]. This
indicates that urb->context, which contains struct si470x_device
object, is freed when si470x_int_in_callback() is called.
The cause of this issue is that si470x_int_in_callback() is called for
freed urb.
si470x_usb_driver_probe() calls si470x_start_usb(), which then calls
usb_submit_urb() and si470x_start(). If si470x_start_usb() fails,
si470x_usb_driver_probe() doesn't kill urb, but it just frees struct
si470x_device object, as depicted below:
si470x_usb_driver_probe()
...
si470x_start_usb()
...
usb_submit_urb()
retval = si470x_start()
return retval
if (retval < 0)
free struct si470x_device object, but don't kill urb
This patch fixes this issue by killing urb when si470x_start_usb()
fails and urb is submitted. If si470x_start_usb() fails and urb is
not submitted, i.e. submitting usb fails, it just frees struct
si470x_device object.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()
xhci_alloc_stream_info() allocates stream context array for stream_info
->stream_ctx_array with xhci_alloc_stream_ctx(). When some error occurs,
stream_info->stream_ctx_array is not released, which will lead to a
memory leak.
We can fix it by releasing the stream_info->stream_ctx_array with
xhci_free_stream_ctx() on the error path to avoid the potential memory
leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
r6040: Fix kmemleak in probe and remove
There is a memory leaks reported by kmemleak:
unreferenced object 0xffff888116111000 (size 2048):
comm "modprobe", pid 817, jiffies 4294759745 (age 76.502s)
hex dump (first 32 bytes):
00 c4 0a 04 81 88 ff ff 08 10 11 16 81 88 ff ff ................
08 10 11 16 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff815bcd82>] kmalloc_trace+0x22/0x60
[<ffffffff827e20ee>] phy_device_create+0x4e/0x90
[<ffffffff827e6072>] get_phy_device+0xd2/0x220
[<ffffffff827e7844>] mdiobus_scan+0xa4/0x2e0
[<ffffffff827e8be2>] __mdiobus_register+0x482/0x8b0
[<ffffffffa01f5d24>] r6040_init_one+0x714/0xd2c [r6040]
...
The problem occurs in probe process as follows:
r6040_init_one:
mdiobus_register
mdiobus_scan <- alloc and register phy_device,
the reference count of phy_device is 3
r6040_mii_probe
phy_connect <- connect to the first phy_device,
so the reference count of the first
phy_device is 4, others are 3
register_netdev <- fault inject succeeded, goto error handling path
// error handling path
err_out_mdio_unregister:
mdiobus_unregister(lp->mii_bus);
err_out_mdio:
mdiobus_free(lp->mii_bus); <- the reference count of the first
phy_device is 1, it is not released
and other phy_devices are released
// similarly, the remove process also has the same problem
The root cause is traced to the phy_device is not disconnected when
removes one r6040 device in r6040_remove_one() or on error handling path
after r6040_mii probed successfully. In r6040_mii_probe(), a net ethernet
device is connected to the first PHY device of mii_bus, in order to
notify the connected driver when the link status changes, which is the
default behavior of the PHY infrastructure to handle everything.
Therefore the phy_device should be disconnected when removes one r6040
device or on error handling path.
Fix it by adding phy_disconnect() when removes one r6040 device or on
error handling path after r6040_mii probed successfully.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07