Security Vulnerabilities
libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.
CVSS Score
7.7
EPSS Score
0.003
Published
2026-07-24
libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packet_length smaller than the cipher's block size during Encrypt-then-MAC cipher negotiation. In the fullpacket() function in src/transport.c, the ETM path allocates a buffer of packet_length bytes but copies blocksize minus one bytes via memcpy, causing an overflow that on 32-bit glibc writes attacker-controlled bytes into an adjacent chunk's SIZE field, enabling tcache bin confusion, overlapping live objects, and function pointer overwrite during the session handshake before authentication.
CVSS Score
7.7
EPSS Score
0.003
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
kernel/fork: clear PF_BLOCK_TS in copy_process()
PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is
non-NULL, and blk_finish_plug() clears it via __blk_flush_plug()
before NULLing the plug pointer. copy_process() breaks the
invariant by inheriting PF_BLOCK_TS from the parent while resetting
the child's plug to NULL.
Clear PF_BLOCK_TS alongside that assignment so callers can rely on
"PF_BLOCK_TS set implies current->plug != NULL" and dereference
current->plug unguarded.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BAR
When BAR_PEER_SPAD and BAR_CONFIG share one PCI BAR, the module teardown
path ends up calling pci_iounmap() on the same iomem with some offset,
which is unnecessary and triggers a kernel warning like the following:
Trying to vunmap() nonexistent vm area (0000000069a5ffe8)
WARNING: mm/vmalloc.c:3470 at vunmap+0x58/0x68, CPU#5: modprobe/2937
[...]
Call trace:
vunmap+0x58/0x68 (P)
iounmap+0x34/0x48
pci_iounmap+0x2c/0x40
ntb_epf_pci_remove+0x44/0x80 [ntb_hw_epf]
pci_device_remove+0x48/0xf8
device_remove+0x50/0x88
device_release_driver_internal+0x1c8/0x228
driver_detach+0x50/0xb0
bus_remove_driver+0x74/0x100
driver_unregister+0x34/0x68
pci_unregister_driver+0x34/0xa0
ntb_epf_pci_driver_exit+0x14/0xfe0 [ntb_hw_epf]
[...]
Fix it by unmapping only when PEER_SPAD and CONFIG use difference bars.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers
Three BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a
station ID without checking that sta_mask is non-zero. When sta_mask is
zero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing
an out-of-bounds access on fw_id_to_link_sta[].
Add WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call,
consistent with the existing check in iwl_mld_ampdu_rx_start().
CVSS Score
8.8
EPSS Score
0.002
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
power: reset: linkstation-poweroff: fix use-after-free in the linkstation_poweroff_init()
Move of_node_put(dn) after the of_match_node() call, which still needs
the node pointer. The node reference is correctly released after use.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: hyper-v: Bound the bank index when querying sparse banks
When checking if a VP ID is included in a sparse bank set, explicitly check
that the ID can actually be contained in a sparse bank (the TLFS allows for
a maximum of 64 banks of 64 vCPUs each). When handling a paravirtual TLB
flush for L2, the VP ID is copied verbatim from the enlightened VMCS,
without any bounds check, i.e. isn't guaranteed to be under the limit of
4096.
Failure to check the bounds of the VP ID leads to an out-of-bounds read
when testing the sparse bank, and super strictly speaking could lead to KVM
performing an unnecessary TLB flush for an L2 vCPU.
==================================================================
BUG: KASAN: use-after-free in hv_is_vp_in_sparse_set+0x85/0x100 [kvm]
Read of size 8 at addr ffff88811ba5f598 by task hyperv_evmcs/2802
CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs Not tainted 7.1.0-rc2 #7 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x51/0x60
print_report+0xcb/0x5d0
kasan_report+0xb4/0xe0
kasan_check_range+0x35/0x1b0
hv_is_vp_in_sparse_set+0x85/0x100 [kvm]
kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm]
kvm_hv_hypercall+0xe6b/0x1e60 [kvm]
vmx_handle_exit+0x485/0x1b60 [kvm_intel]
kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm]
kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm]
__x64_sys_ioctl+0x129/0x1a0
do_syscall_64+0xb9/0xcf0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f0e62d1a9bf
</TASK>
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000
raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
Disabling lock debugging due to kernel taint
Opportunistically add a compile time assertion to ensure the maximum number
of sparse banks exactly matches the number of possible bits in the passed
in mask.
[sean: add KASAN splat, drop comment, add assert, massage changelog]
CVSS Score
8.4
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
MIPS: smp: report dying CPU to RCU in stop_this_cpu()
smp_send_stop() parks all secondary CPUs in stop_this_cpu(). The function
marks the CPU offline for the scheduler via set_cpu_online(false) but
never informs RCU, so RCU keeps expecting a quiescent state from CPUs
that are now spinning forever with interrupts disabled.
As long as nothing waits for an RCU grace period after smp_send_stop()
this is harmless, which is why it went unnoticed. Since commit
91840be8f710 ("irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT")
however, irq_work_sync() calls synchronize_rcu() on architectures without
an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt() returns
false. That is the asm-generic default used by MIPS. Any irq_work_sync()
issued in the reboot/shutdown path after smp_send_stop() then blocks on
a grace period that can never complete, hanging the reboot:
WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on
...
rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
rcu: Offline CPU 1 blocking current GP.
rcu: Offline CPU 2 blocking current GP.
rcu: Offline CPU 3 blocking current GP.
This issue was noticed on several Realtek MIPS switch SoCs (MIPS
interAptiv) and came up during kernel bump downstream in OpenWrt from
6.18.33 to 6.18.34, after the backport of the patch to the 6.18 stable
branch. The patch also has been backported all the way back to 6.1.
Call rcutree_report_cpu_dead() once interrupts are disabled, mirroring the
generic CPU-hotplug offline path, so RCU stops waiting on the parked CPUs
and grace periods can still complete. MIPS shuts down all CPUs here
without going through the CPU-hotplug mechanism, so this report is not
otherwise issued. Reporting a dying CPU to RCU outside the regular hotplug
offline path is not unprecedented: arm64 does the same in cpu_die_early().
There it is an exception for a CPU that was coming online and is aborting
bringup, rather than the default shutdown action as on MIPS.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
fpga: region: fix use-after-free in child_regions_with_firmware()
Move of_node_put(child_region) after the error print to avoid accessing
freed memory when pr_err() references child_region.
[ Yilun: Fix the Fixes tag ]
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Report dying CPU to RCU in stop_this_cpu()
This is a port of MIPS commit 9f3f3bdc6d9dac1 ("MIPS: smp: report dying
CPU to RCU in stop_this_cpu()"). smp_send_stop() parks all secondary
CPUs in stop_this_cpu(). And the function marks the CPU offline for the
scheduler via set_cpu_online(false) but never informs RCU, so RCU keeps
expecting a quiescent state from CPUs that are now spinning forever with
interrupts disabled.
As long as nothing waits for an RCU grace period after smp_send_stop()
this is harmless, which is why it went unnoticed. However, since commit
91840be8f710370 ("irq_work: Fix use-after-free in irq_work_single() on
PREEMPT_RT"), irq_work_sync() calls synchronize_rcu() on architectures
without an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt()
returns false. Any irq_work_sync() issued in the reboot/shutdown/halt
path after smp_send_stop() then blocks on a grace period that can never
complete, hanging the reboot:
WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on
...
rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
rcu: Offline CPU 1 blocking current GP.
rcu: Offline CPU 2 blocking current GP.
rcu: Offline CPU 3 blocking current GP.
This issue needs some hacks to reproduce, and it was not noticed on
LoongArch because arch_irq_work_has_interrupt() usually returns true.
Call rcutree_report_cpu_dead() once interrupts are disabled, mirroring
the generic CPU-hotplug offline path, so RCU stops waiting on the parked
CPUs and grace periods can still complete. LoongArch shuts down all CPUs
here without going through the CPU-hotplug mechanism, so this report is
not otherwise issued.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-24