Linux: >> Linux Kernel >> 4.19.198 Security Vulnerabilities
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:
tipc: fix a null-ptr-deref in tipc_topsrv_accept
syzbot found a crash in tipc_topsrv_accept:
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
Workqueue: tipc_rcv tipc_topsrv_accept
RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487
Call Trace:
<TASK>
tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460
process_one_work+0x991/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
It was caused by srv->listener that might be set to null by
tipc_topsrv_stop() in net .exit whereas it's still used in
tipc_topsrv_accept() worker.
srv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add
a check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to
avoid the null-ptr-deref. To ensure the lsock is not released during the
tipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop()
where it's waiting until the tipc_topsrv_accept worker to be done.
Note that sk_callback_lock is used to protect sk->sk_user_data instead of
srv->listener, and it should check srv in tipc_topsrv_listener_data_ready()
instead. This also ensures that no more tipc_topsrv_accept worker will be
started after tipc_conn_close() is called in tipc_topsrv_stop() where it
sets sk->sk_user_data to null.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: Fix potential shift-out-of-bounds in brcmf_fw_alloc_request()
This patch fixes a shift-out-of-bounds in brcmfmac that occurs in
BIT(chiprev) when a 'chiprev' provided by the device is too large.
It should also not be equal to or greater than BITS_PER_TYPE(u32)
as we do bitwise AND with a u32 variable and BIT(chiprev). The patch
adds a check that makes the function return NULL if that is the case.
Note that the NULL case is later handled by the bus-specific caller,
brcmf_usb_probe_cb() or brcmf_usb_reset_resume(), for example.
Found by a modified version of syzkaller.
UBSAN: shift-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
shift exponent 151055786 is too large for 64-bit type 'long unsigned int'
CPU: 0 PID: 1885 Comm: kworker/0:2 Tainted: G O 5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: usb_hub_wq hub_event
Call Trace:
dump_stack_lvl+0x57/0x7d
ubsan_epilogue+0x5/0x40
__ubsan_handle_shift_out_of_bounds.cold+0x53/0xdb
? lock_chain_count+0x20/0x20
brcmf_fw_alloc_request.cold+0x19/0x3ea
? brcmf_fw_get_firmwares+0x250/0x250
? brcmf_usb_ioctl_resp_wait+0x1a7/0x1f0
brcmf_usb_get_fwname+0x114/0x1a0
? brcmf_usb_reset_resume+0x120/0x120
? number+0x6c4/0x9a0
brcmf_c_process_clm_blob+0x168/0x590
? put_dec+0x90/0x90
? enable_ptr_key_workfn+0x20/0x20
? brcmf_common_pd_remove+0x50/0x50
? rcu_read_lock_sched_held+0xa1/0xd0
brcmf_c_preinit_dcmds+0x673/0xc40
? brcmf_c_set_joinpref_default+0x100/0x100
? rcu_read_lock_sched_held+0xa1/0xd0
? rcu_read_lock_bh_held+0xb0/0xb0
? lock_acquire+0x19d/0x4e0
? find_held_lock+0x2d/0x110
? brcmf_usb_deq+0x1cc/0x260
? mark_held_locks+0x9f/0xe0
? lockdep_hardirqs_on_prepare+0x273/0x3e0
? _raw_spin_unlock_irqrestore+0x47/0x50
? trace_hardirqs_on+0x1c/0x120
? brcmf_usb_deq+0x1a7/0x260
? brcmf_usb_rx_fill_all+0x5a/0xf0
brcmf_attach+0x246/0xd40
? wiphy_new_nm+0x1476/0x1d50
? kmemdup+0x30/0x40
brcmf_usb_probe+0x12de/0x1690
? brcmf_usbdev_qinit.constprop.0+0x470/0x470
usb_probe_interface+0x25f/0x710
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
? usb_match_id.part.0+0x88/0xc0
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
? driver_allows_async_probing+0x120/0x120
bus_for_each_drv+0x123/0x1a0
? bus_rescan_devices+0x20/0x20
? lockdep_hardirqs_on_prepare+0x273/0x3e0
? trace_hardirqs_on+0x1c/0x120
__device_attach+0x207/0x330
? device_bind_driver+0xb0/0xb0
? kobject_uevent_env+0x230/0x12c0
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
? __mutex_unlock_slowpath+0xe7/0x660
? __fw_devlink_link_to_suppliers+0x550/0x550
usb_set_configuration+0x984/0x1770
? kernfs_create_link+0x175/0x230
usb_generic_driver_probe+0x69/0x90
usb_probe_device+0x9c/0x220
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
? driver_allows_async_probing+0x120/0x120
bus_for_each_drv+0x123/0x1a0
? bus_rescan_devices+0x20/0x20
? lockdep_hardirqs_on_prepare+0x273/0x3e0
? trace_hardirqs_on+0x1c/0x120
__device_attach+0x207/0x330
? device_bind_driver+0xb0/0xb0
? kobject_uevent_env+0x230/0x12c0
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
? __fw_devlink_link_to_suppliers+0x550/0x550
usb_new_device.cold+0x463/0xf66
? hub_disconnect+0x400/0x400
? _raw_spin_unlock_irq+0x24/0x30
hub_event+0x10d5/0x3330
? hub_port_debounce+0x280/0x280
? __lock_acquire+0x1671/0x5790
? wq_calc_node_cpumask+0x170/0x2a0
? lock_release+0x640/0x640
? rcu_read_lock_sched_held+0xa1/0xd0
? rcu_read_lock_bh_held+0xb0/0xb0
? lockdep_hardirqs_on_prepare+0x273/0x3e0
process_one_work+0x873/0x13e0
? lock_release+0x640/0x640
? pwq_dec_nr_in_flight+0x320/0x320
? rwlock_bug.part.0+0x90/0x90
worker_thread+0x8b/0xd10
? __kthread_parkme+0xd9/0x1d0
? pr
---truncated---
CVSS Score
7.1
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: use quiesced elevator switch when reinitializing queues
The hctx's run_work may be racing with the elevator switch when
reinitializing hardware queues. The queue is merely frozen in this
context, but that only prevents requests from allocating and doesn't
stop the hctx work from running. The work may get an elevator pointer
that's being torn down, and can result in use-after-free errors and
kernel panics (example below). Use the quiesced elevator switch instead,
and make the previous one static since it is now only used locally.
nvme nvme0: resetting controller
nvme nvme0: 32/0/0 default/read/poll queues
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 80000020c8861067 P4D 80000020c8861067 PUD 250f8c8067 PMD 0
Oops: 0000 [#1] SMP PTI
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:kyber_has_work+0x29/0x70
...
Call Trace:
__blk_mq_do_dispatch_sched+0x83/0x2b0
__blk_mq_sched_dispatch_requests+0x12e/0x170
blk_mq_sched_dispatch_requests+0x30/0x60
__blk_mq_run_hw_queue+0x2b/0x50
process_one_work+0x1ef/0x380
worker_thread+0x2d/0x3e0
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
blk-iolatency: Fix memory leak on add_disk() failures
When a gendisk is successfully initialized but add_disk() fails such as when
a loop device has invalid number of minor device numbers specified,
blkcg_init_disk() is called during init and then blkcg_exit_disk() during
error handling. Unfortunately, iolatency gets initialized in the former but
doesn't get cleaned up in the latter.
This is because, in non-error cases, the cleanup is performed by
del_gendisk() calling rq_qos_exit(), the assumption being that rq_qos
policies, iolatency being one of them, can only be activated once the disk
is fully registered and visible. That assumption is true for wbt and iocost,
but not so for iolatency as it gets initialized before add_disk() is called.
It is desirable to lazy-init rq_qos policies because they are optional
features and add to hot path overhead once initialized - each IO has to walk
all the registered rq_qos policies. So, we want to switch iolatency to lazy
init too. However, that's a bigger change. As a fix for the immediate
problem, let's just add an extra call to rq_qos_exit() in blkcg_exit_disk().
This is safe because duplicate calls to rq_qos_exit() become noop's.
CVSS Score
5.5
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:
vme: Fix error not catched in fake_init()
In fake_init(), __root_device_register() is possible to fail but it's
ignored, which can cause unregistering vme_root fail when exit.
general protection fault,
probably for non-canonical address 0xdffffc000000008c
KASAN: null-ptr-deref in range [0x0000000000000460-0x0000000000000467]
RIP: 0010:root_device_unregister+0x26/0x60
Call Trace:
<TASK>
__x64_sys_delete_module+0x34f/0x540
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Return error when __root_device_register() fails.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07