Linux: >> Linux Kernel >> 4.14.139 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Acquire SRCU in KVM_GET_MP_STATE to protect guest memory accesses
Acquire a lock on kvm->srcu when userspace is getting MP state to handle a
rather extreme edge case where "accepting" APIC events, i.e. processing
pending INIT or SIPI, can trigger accesses to guest memory. If the vCPU
is in L2 with INIT *and* a TRIPLE_FAULT request pending, then getting MP
state will trigger a nested VM-Exit by way of ->check_nested_events(), and
emuating the nested VM-Exit can access guest memory.
The splat was originally hit by syzkaller on a Google-internal kernel, and
reproduced on an upstream kernel by hacking the triple_fault_event_test
selftest to stuff a pending INIT, store an MSR on VM-Exit (to generate a
memory access on VMX), and do vcpu_mp_state_get() to trigger the scenario.
=============================
WARNING: suspicious RCU usage
6.14.0-rc3-b112d356288b-vmx/pi_lockdep_false_pos-lock #3 Not tainted
-----------------------------
include/linux/kvm_host.h:1058 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by triple_fault_ev/1256:
#0: ffff88810df5a330 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x8b/0x9a0 [kvm]
stack backtrace:
CPU: 11 UID: 1000 PID: 1256 Comm: triple_fault_ev Not tainted 6.14.0-rc3-b112d356288b-vmx #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x7f/0x90
lockdep_rcu_suspicious+0x144/0x190
kvm_vcpu_gfn_to_memslot+0x156/0x180 [kvm]
kvm_vcpu_read_guest+0x3e/0x90 [kvm]
read_and_check_msr_entry+0x2e/0x180 [kvm_intel]
__nested_vmx_vmexit+0x550/0xde0 [kvm_intel]
kvm_check_nested_events+0x1b/0x30 [kvm]
kvm_apic_accept_events+0x33/0x100 [kvm]
kvm_arch_vcpu_ioctl_get_mpstate+0x30/0x1d0 [kvm]
kvm_vcpu_ioctl+0x33e/0x9a0 [kvm]
__x64_sys_ioctl+0x8b/0xb0
do_syscall_64+0x6c/0x170
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-01
In the Linux kernel, the following vulnerability has been resolved:
HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition
In the ssi_protocol_probe() function, &ssi->work is bound with
ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function
within the ssip_pn_ops structure is capable of starting the
work.
If we remove the module which will call ssi_protocol_remove()
to make a cleanup, it will free ssi through kfree(ssi),
while the work mentioned above will be used. The sequence
of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ssip_xmit_work
ssi_protocol_remove |
kfree(ssi); |
| struct hsi_client *cl = ssi->cl;
| // use ssi
Fix it by ensuring that the work is canceled before proceeding
with the cleanup in ssi_protocol_remove().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
jfs: reject on-disk inodes of an unsupported type
Syzbot has reported the following BUG:
kernel BUG at fs/inode.c:668!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 UID: 0 PID: 139 Comm: jfsCommit Not tainted 6.12.0-rc4-syzkaller-00085-g4e46774408d9 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
RIP: 0010:clear_inode+0x168/0x190
Code: 4c 89 f7 e8 ba fe e5 ff e9 61 ff ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 7c c1 4c 89 f7 e8 90 ff e5 ff eb b7
0b e8 01 5d 7f ff 90 0f 0b e8 f9 5c 7f ff 90 0f 0b e8 f1 5c 7f
RSP: 0018:ffffc900027dfae8 EFLAGS: 00010093
RAX: ffffffff82157a87 RBX: 0000000000000001 RCX: ffff888104d4b980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900027dfc90 R08: ffffffff82157977 R09: fffff520004fbf38
R10: dffffc0000000000 R11: fffff520004fbf38 R12: dffffc0000000000
R13: ffff88811315bc00 R14: ffff88811315bda8 R15: ffff88811315bb80
FS: 0000000000000000(0000) GS:ffff888135f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005565222e0578 CR3: 0000000026ef0000 CR4: 00000000000006f0
Call Trace:
<TASK>
? __die_body+0x5f/0xb0
? die+0x9e/0xc0
? do_trap+0x15a/0x3a0
? clear_inode+0x168/0x190
? do_error_trap+0x1dc/0x2c0
? clear_inode+0x168/0x190
? __pfx_do_error_trap+0x10/0x10
? report_bug+0x3cd/0x500
? handle_invalid_op+0x34/0x40
? clear_inode+0x168/0x190
? exc_invalid_op+0x38/0x50
? asm_exc_invalid_op+0x1a/0x20
? clear_inode+0x57/0x190
? clear_inode+0x167/0x190
? clear_inode+0x168/0x190
? clear_inode+0x167/0x190
jfs_evict_inode+0xb5/0x440
? __pfx_jfs_evict_inode+0x10/0x10
evict+0x4ea/0x9b0
? __pfx_evict+0x10/0x10
? iput+0x713/0xa50
txUpdateMap+0x931/0xb10
? __pfx_txUpdateMap+0x10/0x10
jfs_lazycommit+0x49a/0xb80
? _raw_spin_unlock_irqrestore+0x8f/0x140
? lockdep_hardirqs_on+0x99/0x150
? __pfx_jfs_lazycommit+0x10/0x10
? __pfx_default_wake_function+0x10/0x10
? __kthread_parkme+0x169/0x1d0
? __pfx_jfs_lazycommit+0x10/0x10
kthread+0x2f2/0x390
? __pfx_jfs_lazycommit+0x10/0x10
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4d/0x80
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This happens when 'clear_inode()' makes an attempt to finalize an underlying
JFS inode of unknown type. According to JFS layout description from
https://jfs.sourceforge.net/project/pub/jfslayout.pdf, inode types from 5 to
15 are reserved for future extensions and should not be encountered on a valid
filesystem. So add an extra check for valid inode type in 'copy_from_dinode()'.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix OOB read when checking dotdot dir
Mounting a corrupted filesystem with directory which contains '.' dir
entry with rec_len == block size results in out-of-bounds read (later
on, when the corrupted directory is removed).
ext4_empty_dir() assumes every ext4 directory contains at least '.'
and '..' as directory entries in the first data block. It first loads
the '.' dir entry, performs sanity checks by calling ext4_check_dir_entry()
and then uses its rec_len member to compute the location of '..' dir
entry (in ext4_next_entry). It assumes the '..' dir entry fits into the
same data block.
If the rec_len of '.' is precisely one block (4KB), it slips through the
sanity checks (it is considered the last directory entry in the data
block) and leaves "struct ext4_dir_entry_2 *de" point exactly past the
memory slot allocated to the data block. The following call to
ext4_check_dir_entry() on new value of de then dereferences this pointer
which results in out-of-bounds mem access.
Fix this by extending __ext4_check_dir_entry() to check for '.' dir
entries that reach the end of data block. Make sure to ignore the phony
dir entries for checksum (by checking name_len for non-zero).
Note: This is reported by KASAN as use-after-free in case another
structure was recently freed from the slot past the bound, but it is
really an OOB read.
This issue was found by syzkaller tool.
Call Trace:
[ 38.594108] BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x67e/0x710
[ 38.594649] Read of size 2 at addr ffff88802b41a004 by task syz-executor/5375
[ 38.595158]
[ 38.595288] CPU: 0 UID: 0 PID: 5375 Comm: syz-executor Not tainted 6.14.0-rc7 #1
[ 38.595298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 38.595304] Call Trace:
[ 38.595308] <TASK>
[ 38.595311] dump_stack_lvl+0xa7/0xd0
[ 38.595325] print_address_description.constprop.0+0x2c/0x3f0
[ 38.595339] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595349] print_report+0xaa/0x250
[ 38.595359] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595368] ? kasan_addr_to_slab+0x9/0x90
[ 38.595378] kasan_report+0xab/0xe0
[ 38.595389] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595400] __ext4_check_dir_entry+0x67e/0x710
[ 38.595410] ext4_empty_dir+0x465/0x990
[ 38.595421] ? __pfx_ext4_empty_dir+0x10/0x10
[ 38.595432] ext4_rmdir.part.0+0x29a/0xd10
[ 38.595441] ? __dquot_initialize+0x2a7/0xbf0
[ 38.595455] ? __pfx_ext4_rmdir.part.0+0x10/0x10
[ 38.595464] ? __pfx___dquot_initialize+0x10/0x10
[ 38.595478] ? down_write+0xdb/0x140
[ 38.595487] ? __pfx_down_write+0x10/0x10
[ 38.595497] ext4_rmdir+0xee/0x140
[ 38.595506] vfs_rmdir+0x209/0x670
[ 38.595517] ? lookup_one_qstr_excl+0x3b/0x190
[ 38.595529] do_rmdir+0x363/0x3c0
[ 38.595537] ? __pfx_do_rmdir+0x10/0x10
[ 38.595544] ? strncpy_from_user+0x1ff/0x2e0
[ 38.595561] __x64_sys_unlinkat+0xf0/0x130
[ 38.595570] do_syscall_64+0x5b/0x180
[ 38.595583] entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS Score
7.1
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
can: dev: can_restart: fix use after free bug
After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the netif_rx_ni() in:
stats->rx_bytes += cf->len;
Reordering the lines solves the issue.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-17
In the Linux kernel, the following vulnerability has been resolved:
can: vxcan: vxcan_xmit: fix use after free bug
After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the canfd_frame cfd which aliases skb memory is accessed
after the netif_rx_ni().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-17
In the Linux kernel, the following vulnerability has been resolved:
can: peak_usb: fix use after free bugs
After calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the peak_usb_netif_rx_ni().
Reordering the lines solves the issue.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-17
In the Linux kernel, the following vulnerability has been resolved:
can: dev: can_get_echo_skb(): prevent call to kfree_skb() in hard IRQ context
If a driver calls can_get_echo_skb() during a hardware IRQ (which is often, but
not always, the case), the 'WARN_ON(in_irq)' in
net/core/skbuff.c#skb_release_head_state() might be triggered, under network
congestion circumstances, together with the potential risk of a NULL pointer
dereference.
The root cause of this issue is the call to kfree_skb() instead of
dev_kfree_skb_irq() in net/core/dev.c#enqueue_to_backlog().
This patch prevents the skb to be freed within the call to netif_rx() by
incrementing its reference count with skb_get(). The skb is finally freed by
one of the in-irq-context safe functions: dev_consume_skb_any() or
dev_kfree_skb_any(). The "any" version is used because some drivers might call
can_get_echo_skb() in a normal context.
The reason for this issue to occur is that initially, in the core network
stack, loopback skb were not supposed to be received in hardware IRQ context.
The CAN stack is an exeption.
This bug was previously reported back in 2017 in [1] but the proposed patch
never got accepted.
While [1] directly modifies net/core/dev.c, we try to propose here a
smoother modification local to CAN network stack (the assumption
behind is that only CAN devices are affected by this issue).
[1] http://lore.kernel.org/r/57a3ffb6-3309-3ad5-5a34-e93c3fe3614d@cetitec.com
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-17
In the Linux kernel, the following vulnerability has been resolved:
dlm: prevent NPD when writing a positive value to event_done
do_uevent returns the value written to event_done. In case it is a
positive value, new_lockspace would undo all the work, and lockspace
would not be set. __dlm_new_lockspace, however, would treat that
positive value as a success due to commit 8511a2728ab8 ("dlm: fix use
count with multiple joins").
Down the line, device_create_lockspace would pass that NULL lockspace to
dlm_find_lockspace_local, leading to a NULL pointer dereference.
Treating such positive values as successes prevents the problem. Given
this has been broken for so long, this is unlikely to break userspace
expectations.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
thermal: int340x: Add NULL check for adev
Not all devices have an ACPI companion fwnode, so adev might be NULL.
This is similar to the commit cd2fd6eab480
("platform/x86: int3472: Check for adev == NULL").
Add a check for adev not being set and return -ENODEV in that case to
avoid a possible NULL pointer deref in int3402_thermal_probe().
Note, under the same directory, int3400_thermal_probe() has such a
check.
[ rjw: Subject edit, added Fixes: ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16