Linux: >> Linux Kernel >> 6.1.124 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag
Truncate an inode's address space when flipping the GFS2_DIF_JDATA flag:
depending on that flag, the pages in the address space will either use
buffer heads or iomap_folio_state structs, and we cannot mix the two.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
fs/proc: fix softlockup in __read_vmcore (part 2)
Since commit 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore") the
number of softlockups in __read_vmcore at kdump time have gone down, but
they still happen sometimes.
In a memory constrained environment like the kdump image, a softlockup is
not just a harmless message, but it can interfere with things like RCU
freeing memory, causing the crashdump to get stuck.
The second loop in __read_vmcore has a lot more opportunities for natural
sleep points, like scheduling out while waiting for a data write to
happen, but apparently that is not always enough.
Add a cond_resched() to the second loop in __read_vmcore to (hopefully)
get rid of the softlockups.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
mm: clear uffd-wp PTE/PMD state on mremap()
When mremap()ing a memory region previously registered with userfaultfd as
write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in
flag clearing leads to a mismatch between the vma flags (which have
uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp
cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to
trigger a warning in page_table_check_pte_flags() due to setting the pte
to writable while uffd-wp is still set.
Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any
such mremap() so that the values are consistent with the existing clearing
of VM_UFFD_WP. Be careful to clear the logical flag regardless of its
physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE,
huge PMD and hugetlb paths.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Ensure job pointer is set to NULL after job completion
After a job completes, the corresponding pointer in the device must
be set to NULL. Failing to do so triggers a warning when unloading
the driver, as it appears the job is still active. To prevent this,
assign the job pointer to NULL after completing the job, indicating
the job has finished.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
hrtimers: Handle CPU state correctly on hotplug
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway
through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to
CPUHP_ONLINE:
Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set
to 1 throughout. However, during a CPU unplug operation, the tick and the
clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online
state, for instance CFS incorrectly assumes that the hrtick is already
active, and the chance of the clockevent device to transition to oneshot
mode is also lost forever for the CPU, unless it goes back to a lower state
than CPUHP_HRTIMERS_PREPARE once.
This round-trip reveals another issue; cpu_base.online is not set to 1
after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer().
Aside of that, the bulk of the per CPU state is not reset either, which
means there are dangling pointers in the worst case.
Address this by adding a corresponding startup() callback, which resets the
stale per CPU state and sets the online flag.
[ tglx: Make the new callback unconditionally available, remove the online
modification in the prepare() callback and clear the remaining
state in the starting callback instead of the prepare callback ]
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
vfio/platform: check the bounds of read/write syscalls
count and offset are passed from user space and not checked, only
offset is capped to 40 bits, which can be used to read/write out of
bounds of the device.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()
This patch addresses a null-ptr-deref in qt2_process_read_urb() due to
an incorrect bounds check in the following:
if (newport > serial->num_ports) {
dev_err(&port->dev,
"%s - port change to invalid port: %i\n",
__func__, newport);
break;
}
The condition doesn't account for the valid range of the serial->port
buffer, which is from 0 to serial->num_ports - 1. When newport is equal
to serial->num_ports, the assignment of "port" in the
following code is out-of-bounds and NULL:
serial_priv->current_port = newport;
port = serial->port[serial_priv->current_port];
The fix checks if newport is greater than or equal to serial->num_ports
indicating it is out-of-bounds.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
scsi: storvsc: Ratelimit warning logs to prevent VM denial of service
If there's a persistent error in the hypervisor, the SCSI warning for
failed I/O can flood the kernel log and max out CPU utilization,
preventing troubleshooting from the VM side. Ratelimit the warning so
it doesn't DoS the VM.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
net: sched: fix ets qdisc OOB Indexing
Haowei Yan <g1042620637@gmail.com> found that ets_class_from_arg() can
index an Out-Of-Bound class in ets_class_from_arg() when passed clid of
0. The overflow may cause local privilege escalation.
[ 18.852298] ------------[ cut here ]------------
[ 18.853271] UBSAN: array-index-out-of-bounds in net/sched/sch_ets.c:93:20
[ 18.853743] index 18446744073709551615 is out of range for type 'ets_class [16]'
[ 18.854254] CPU: 0 UID: 0 PID: 1275 Comm: poc Not tainted 6.12.6-dirty #17
[ 18.854821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[ 18.856532] Call Trace:
[ 18.857441] <TASK>
[ 18.858227] dump_stack_lvl+0xc2/0xf0
[ 18.859607] dump_stack+0x10/0x20
[ 18.860908] __ubsan_handle_out_of_bounds+0xa7/0xf0
[ 18.864022] ets_class_change+0x3d6/0x3f0
[ 18.864322] tc_ctl_tclass+0x251/0x910
[ 18.864587] ? lock_acquire+0x5e/0x140
[ 18.865113] ? __mutex_lock+0x9c/0xe70
[ 18.866009] ? __mutex_lock+0xa34/0xe70
[ 18.866401] rtnetlink_rcv_msg+0x170/0x6f0
[ 18.866806] ? __lock_acquire+0x578/0xc10
[ 18.867184] ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[ 18.867503] netlink_rcv_skb+0x59/0x110
[ 18.867776] rtnetlink_rcv+0x15/0x30
[ 18.868159] netlink_unicast+0x1c3/0x2b0
[ 18.868440] netlink_sendmsg+0x239/0x4b0
[ 18.868721] ____sys_sendmsg+0x3e2/0x410
[ 18.869012] ___sys_sendmsg+0x88/0xe0
[ 18.869276] ? rseq_ip_fixup+0x198/0x260
[ 18.869563] ? rseq_update_cpu_node_id+0x10a/0x190
[ 18.869900] ? trace_hardirqs_off+0x5a/0xd0
[ 18.870196] ? syscall_exit_to_user_mode+0xcc/0x220
[ 18.870547] ? do_syscall_64+0x93/0x150
[ 18.870821] ? __memcg_slab_free_hook+0x69/0x290
[ 18.871157] __sys_sendmsg+0x69/0xd0
[ 18.871416] __x64_sys_sendmsg+0x1d/0x30
[ 18.871699] x64_sys_call+0x9e2/0x2670
[ 18.871979] do_syscall_64+0x87/0x150
[ 18.873280] ? do_syscall_64+0x93/0x150
[ 18.874742] ? lock_release+0x7b/0x160
[ 18.876157] ? do_user_addr_fault+0x5ce/0x8f0
[ 18.877833] ? irqentry_exit_to_user_mode+0xc2/0x210
[ 18.879608] ? irqentry_exit+0x77/0xb0
[ 18.879808] ? clear_bhb_loop+0x15/0x70
[ 18.880023] ? clear_bhb_loop+0x15/0x70
[ 18.880223] ? clear_bhb_loop+0x15/0x70
[ 18.880426] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 18.880683] RIP: 0033:0x44a957
[ 18.880851] Code: ff ff e8 fc 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 8974 24 10
[ 18.881766] RSP: 002b:00007ffcdd00fad8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 18.882149] RAX: ffffffffffffffda RBX: 00007ffcdd010db8 RCX: 000000000044a957
[ 18.882507] RDX: 0000000000000000 RSI: 00007ffcdd00fb70 RDI: 0000000000000003
[ 18.885037] RBP: 00007ffcdd010bc0 R08: 000000000703c770 R09: 000000000703c7c0
[ 18.887203] R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000001
[ 18.888026] R13: 00007ffcdd010da8 R14: 00000000004ca7d0 R15: 0000000000000001
[ 18.888395] </TASK>
[ 18.888610] ---[ end trace ]---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
mm: zswap: properly synchronize freeing resources during CPU hotunplug
In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the
current CPU at the beginning of the operation is retrieved and used
throughout. However, since neither preemption nor migration are disabled,
it is possible that the operation continues on a different CPU.
If the original CPU is hotunplugged while the acomp_ctx is still in use,
we run into a UAF bug as some of the resources attached to the acomp_ctx
are freed during hotunplug in zswap_cpu_comp_dead() (i.e.
acomp_ctx.buffer, acomp_ctx.req, or acomp_ctx.acomp).
The problem was introduced in commit 1ec3b5fe6eec ("mm/zswap: move to use
crypto_acomp API for hardware acceleration") when the switch to the
crypto_acomp API was made. Prior to that, the per-CPU crypto_comp was
retrieved using get_cpu_ptr() which disables preemption and makes sure the
CPU cannot go away from under us. Preemption cannot be disabled with the
crypto_acomp API as a sleepable context is needed.
Use the acomp_ctx.mutex to synchronize CPU hotplug callbacks allocating
and freeing resources with compression/decompression paths. Make sure
that acomp_ctx.req is NULL when the resources are freed. In the
compression/decompression paths, check if acomp_ctx.req is NULL after
acquiring the mutex (meaning the CPU was offlined) and retry on the new
CPU.
The initialization of acomp_ctx.mutex is moved from the CPU hotplug
callback to the pool initialization where it belongs (where the mutex is
allocated). In addition to adding clarity, this makes sure that CPU
hotplug cannot reinitialize a mutex that is already locked by
compression/decompression.
Previously a fix was attempted by holding cpus_read_lock() [1]. This
would have caused a potential deadlock as it is possible for code already
holding the lock to fall into reclaim and enter zswap (causing a
deadlock). A fix was also attempted using SRCU for synchronization, but
Johannes pointed out that synchronize_srcu() cannot be used in CPU hotplug
notifiers [2].
Alternative fixes that were considered/attempted and could have worked:
- Refcounting the per-CPU acomp_ctx. This involves complexity in
handling the race between the refcount dropping to zero in
zswap_[de]compress() and the refcount being re-initialized when the
CPU is onlined.
- Disabling migration before getting the per-CPU acomp_ctx [3], but
that's discouraged and is a much bigger hammer than needed, and could
result in subtle performance issues.
[1]https://lkml.kernel.org/20241219212437.2714151-1-yosryahmed@google.com/
[2]https://lkml.kernel.org/20250107074724.1756696-2-yosryahmed@google.com/
[3]https://lkml.kernel.org/20250107222236.2715883-2-yosryahmed@google.com/
[yosryahmed@google.com: remove comment]
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-10