Linux: >> Linux Kernel >> 4.16.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix deadlock in nilfs_count_free_blocks()
A semaphore deadlock can occur if nilfs_get_block() detects metadata
corruption while locating data blocks and a superblock writeback occurs at
the same time:
task 1 task 2
------ ------
* A file operation *
nilfs_truncate()
nilfs_get_block()
down_read(rwsem A) <--
nilfs_bmap_lookup_contig()
... generic_shutdown_super()
nilfs_put_super()
* Prepare to write superblock *
down_write(rwsem B) <--
nilfs_cleanup_super()
* Detect b-tree corruption * nilfs_set_log_cursor()
nilfs_bmap_convert_error() nilfs_count_free_blocks()
__nilfs_error() down_read(rwsem A) <--
nilfs_set_error()
down_write(rwsem B) <--
*** DEADLOCK ***
Here, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem)
and then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata
corruption, __nilfs_error() is called from nilfs_bmap_convert_error()
inside the lock section.
Since __nilfs_error() calls nilfs_set_error() unless the filesystem is
read-only and nilfs_set_error() attempts to writelock rwsem B (=
nilfs->ns_sem) to write back superblock exclusively, hierarchical lock
acquisition occurs in the order rwsem A -> rwsem B.
Now, if another task starts updating the superblock, it may writelock
rwsem B during the lock sequence above, and can deadlock trying to
readlock rwsem A in nilfs_count_free_blocks().
However, there is actually no need to take rwsem A in
nilfs_count_free_blocks() because it, within the lock section, only reads
a single integer data on a shared struct with
nilfs_sufile_get_ncleansegs(). This has been the case after commit
aa474a220180 ("nilfs2: add local variable to cache the number of clean
segments"), that is, even before this bug was introduced.
So, this resolves the deadlock problem by just not taking the semaphore in
nilfs_count_free_blocks().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
riscv: process: fix kernel info leakage
thread_struct's s[12] may contain random kernel memory content, which
may be finally leaked to userspace. This is a security hole. Fix it
by clearing the s[12] array in thread_struct when fork.
As for kthread case, it's better to clear the s[12] array as well.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
net: macvlan: fix memory leaks of macvlan_common_newlink
kmemleak reports memory leaks in macvlan_common_newlink, as follows:
ip link add link eth0 name .. type macvlan mode source macaddr add
<MAC-ADDR>
kmemleak reports:
unreferenced object 0xffff8880109bb140 (size 64):
comm "ip", pid 284, jiffies 4294986150 (age 430.108s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 b8 aa 5a 12 80 88 ff ff ..........Z.....
80 1b fa 0d 80 88 ff ff 1e ff ac af c7 c1 6b 6b ..............kk
backtrace:
[<ffffffff813e06a7>] kmem_cache_alloc_trace+0x1c7/0x300
[<ffffffff81b66025>] macvlan_hash_add_source+0x45/0xc0
[<ffffffff81b66a67>] macvlan_changelink_sources+0xd7/0x170
[<ffffffff81b6775c>] macvlan_common_newlink+0x38c/0x5a0
[<ffffffff81b6797e>] macvlan_newlink+0xe/0x20
[<ffffffff81d97f8f>] __rtnl_newlink+0x7af/0xa50
[<ffffffff81d98278>] rtnl_newlink+0x48/0x70
...
In the scenario where the macvlan mode is configured as 'source',
macvlan_changelink_sources() will be execured to reconfigure list of
remote source mac addresses, at the same time, if register_netdevice()
return an error, the resource generated by macvlan_changelink_sources()
is not cleaned up.
Using this patch, in the case of an error, it will execute
macvlan_flush_sources() to ensure that the resource is cleaned up.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
siox: fix possible memory leak in siox_device_add()
If device_register() returns error in siox_device_add(),
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(), and sdevice is freed in siox_device_release(),
set it to null in error path.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
sctp: clear out_curr if all frag chunks of current msg are pruned
A crash was reported by Zhen Chen:
list_del corruption, ffffa035ddf01c18->next is NULL
WARNING: CPU: 1 PID: 250682 at lib/list_debug.c:49 __list_del_entry_valid+0x59/0xe0
RIP: 0010:__list_del_entry_valid+0x59/0xe0
Call Trace:
sctp_sched_dequeue_common+0x17/0x70 [sctp]
sctp_sched_fcfs_dequeue+0x37/0x50 [sctp]
sctp_outq_flush_data+0x85/0x360 [sctp]
sctp_outq_uncork+0x77/0xa0 [sctp]
sctp_cmd_interpreter.constprop.0+0x164/0x1450 [sctp]
sctp_side_effects+0x37/0xe0 [sctp]
sctp_do_sm+0xd0/0x230 [sctp]
sctp_primitive_SEND+0x2f/0x40 [sctp]
sctp_sendmsg_to_asoc+0x3fa/0x5c0 [sctp]
sctp_sendmsg+0x3d5/0x440 [sctp]
sock_sendmsg+0x5b/0x70
and in sctp_sched_fcfs_dequeue() it dequeued a chunk from stream
out_curr outq while this outq was empty.
Normally stream->out_curr must be set to NULL once all frag chunks of
current msg are dequeued, as we can see in sctp_sched_dequeue_done().
However, in sctp_prsctp_prune_unsent() as it is not a proper dequeue,
sctp_sched_dequeue_done() is not called to do this.
This patch is to fix it by simply setting out_curr to NULL when the
last frag chunk of current msg is dequeued from out_curr stream in
sctp_prsctp_prune_unsent().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
scsi: scsi_transport_sas: Fix error handling in sas_phy_add()
If transport_add_device() fails in sas_phy_add(), the kernel will crash
trying to delete the device in transport_remove_device() called from
sas_remove_host().
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000108
CPU: 61 PID: 42829 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc1+ #173
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : device_del+0x54/0x3d0
lr : device_del+0x37c/0x3d0
Call trace:
device_del+0x54/0x3d0
attribute_container_class_device_del+0x28/0x38
transport_remove_classdev+0x6c/0x80
attribute_container_device_trigger+0x108/0x110
transport_remove_device+0x28/0x38
sas_phy_delete+0x30/0x60 [scsi_transport_sas]
do_sas_phy_delete+0x6c/0x80 [scsi_transport_sas]
device_for_each_child+0x68/0xb0
sas_remove_children+0x40/0x50 [scsi_transport_sas]
sas_remove_host+0x20/0x38 [scsi_transport_sas]
hisi_sas_remove+0x40/0x68 [hisi_sas_main]
hisi_sas_v2_remove+0x20/0x30 [hisi_sas_v2_hw]
platform_remove+0x2c/0x60
Fix this by checking and handling return value of transport_add_device()
in sas_phy_add().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
bpf, test_run: Fix alignment problem in bpf_prog_test_run_skb()
We got a syzkaller problem because of aarch64 alignment fault
if KFENCE enabled. When the size from user bpf program is an odd
number, like 399, 407, etc, it will cause the struct skb_shared_info's
unaligned access. As seen below:
BUG: KFENCE: use-after-free read in __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032
Use-after-free read at 0xffff6254fffac077 (in kfence-#213):
__lse_atomic_add arch/arm64/include/asm/atomic_lse.h:26 [inline]
arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline]
arch_atomic_inc include/linux/atomic-arch-fallback.h:270 [inline]
atomic_inc include/asm-generic/atomic-instrumented.h:241 [inline]
__skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032
skb_clone+0xf4/0x214 net/core/skbuff.c:1481
____bpf_clone_redirect net/core/filter.c:2433 [inline]
bpf_clone_redirect+0x78/0x1c0 net/core/filter.c:2420
bpf_prog_d3839dd9068ceb51+0x80/0x330
bpf_dispatcher_nop_func include/linux/bpf.h:728 [inline]
bpf_test_run+0x3c0/0x6c0 net/bpf/test_run.c:53
bpf_prog_test_run_skb+0x638/0xa7c net/bpf/test_run.c:594
bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline]
__do_sys_bpf kernel/bpf/syscall.c:4441 [inline]
__se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381
kfence-#213: 0xffff6254fffac000-0xffff6254fffac196, size=407, cache=kmalloc-512
allocated by task 15074 on cpu 0 at 1342.585390s:
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:675 [inline]
bpf_test_init.isra.0+0xac/0x290 net/bpf/test_run.c:191
bpf_prog_test_run_skb+0x11c/0xa7c net/bpf/test_run.c:512
bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline]
__do_sys_bpf kernel/bpf/syscall.c:4441 [inline]
__se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381
__arm64_sys_bpf+0x50/0x60 kernel/bpf/syscall.c:4381
To fix the problem, we adjust @size so that (@size + @hearoom) is a
multiple of SMP_CACHE_BYTES. So we make sure the struct skb_shared_info
is aligned to a cache line.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
serial: imx: Add missing .thaw_noirq hook
The following warning is seen with non-console UART instance when
system hibernates.
[ 37.371969] ------------[ cut here ]------------
[ 37.376599] uart3_root_clk already disabled
[ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0
...
[ 37.506986] Call trace:
[ 37.509432] clk_core_disable+0xa4/0xb0
[ 37.513270] clk_disable+0x34/0x50
[ 37.516672] imx_uart_thaw+0x38/0x5c
[ 37.520250] platform_pm_thaw+0x30/0x6c
[ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4
[ 37.528972] device_resume+0x7c/0x160
[ 37.532633] dpm_resume+0xe8/0x230
[ 37.536036] hibernation_snapshot+0x288/0x430
[ 37.540397] hibernate+0x10c/0x2e0
[ 37.543798] state_store+0xc4/0xd0
[ 37.547203] kobj_attr_store+0x1c/0x30
[ 37.550953] sysfs_kf_write+0x48/0x60
[ 37.554619] kernfs_fop_write_iter+0x118/0x1ac
[ 37.559063] new_sync_write+0xe8/0x184
[ 37.562812] vfs_write+0x230/0x290
[ 37.566214] ksys_write+0x68/0xf4
[ 37.569529] __arm64_sys_write+0x20/0x2c
[ 37.573452] invoke_syscall.constprop.0+0x50/0xf0
[ 37.578156] do_el0_svc+0x11c/0x150
[ 37.581648] el0_svc+0x30/0x140
[ 37.584792] el0t_64_sync_handler+0xe8/0xf0
[ 37.588976] el0t_64_sync+0x1a0/0x1a4
[ 37.592639] ---[ end trace 56e22eec54676d75 ]---
On hibernating, pm core calls into related hooks in sequence like:
.freeze
.freeze_noirq
.thaw_noirq
.thaw
With .thaw_noirq hook being absent, the clock will be disabled in a
unbalanced call which results the warning above.
imx_uart_freeze()
clk_prepare_enable()
imx_uart_suspend_noirq()
clk_disable()
imx_uart_thaw
clk_disable_unprepare()
Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have
the call sequence corrected as below and thus fix the warning.
imx_uart_freeze()
clk_prepare_enable()
imx_uart_suspend_noirq()
clk_disable()
imx_uart_resume_noirq()
clk_enable()
imx_uart_thaw
clk_disable_unprepare()
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
ASoC: core: Fix use-after-free in snd_soc_exit()
KASAN reports a use-after-free:
BUG: KASAN: use-after-free in device_del+0xb5b/0xc60
Read of size 8 at addr ffff888008655050 by task rmmod/387
CPU: 2 PID: 387 Comm: rmmod
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl+0x79/0x9a
print_report+0x17f/0x47b
kasan_report+0xbb/0xf0
device_del+0xb5b/0xc60
platform_device_del.part.0+0x24/0x200
platform_device_unregister+0x2e/0x40
snd_soc_exit+0xa/0x22 [snd_soc_core]
__do_sys_delete_module.constprop.0+0x34f/0x5b0
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
It's bacause in snd_soc_init(), snd_soc_util_init() is possble to fail,
but its ret is ignored, which makes soc_dummy_dev unregistered twice.
snd_soc_init()
snd_soc_util_init()
platform_device_register_simple(soc_dummy_dev)
platform_driver_register() # fail
platform_device_unregister(soc_dummy_dev)
platform_driver_register() # success
...
snd_soc_exit()
snd_soc_util_exit()
# soc_dummy_dev will be unregistered for second time
To fix it, handle error and stop snd_soc_init() when util_init() fail.
Also clean debugfs when util_init() or driver_register() fail.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
hugetlbfs: don't delete error page from pagecache
This change is very similar to the change that was made for shmem [1], and
it solves the same problem but for HugeTLBFS instead.
Currently, when poison is found in a HugeTLB page, the page is removed
from the page cache. That means that attempting to map or read that
hugepage in the future will result in a new hugepage being allocated
instead of notifying the user that the page was poisoned. As [1] states,
this is effectively memory corruption.
The fix is to leave the page in the page cache. If the user attempts to
use a poisoned HugeTLB page with a syscall, the syscall will fail with
EIO, the same error code that shmem uses. For attempts to map the page,
the thread will get a BUS_MCEERR_AR SIGBUS.
[1]: commit a76054266661 ("mm: shmem: don't truncate page if memory failure happens")
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01