Linux: >> Linux Kernel >> 5.4.11 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
pmdomain: core: Fix detach procedure for virtual devices in genpd
If a device is attached to a PM domain through genpd_dev_pm_attach_by_id(),
genpd calls pm_runtime_enable() for the corresponding virtual device that
it registers. While this avoids boilerplate code in drivers, there is no
corresponding call to pm_runtime_disable() in genpd_dev_pm_detach().
This means these virtual devices are typically detached from its genpd,
while runtime PM remains enabled for them, which is not how things are
designed to work. In worst cases it may lead to critical errors, like a
NULL pointer dereference bug in genpd_runtime_suspend(), which was recently
reported. For another case, we may end up keeping an unnecessary vote for a
performance state for the device.
To fix these problems, let's add this missing call to pm_runtime_disable()
in genpd_dev_pm_detach().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
dm: fix a buffer overflow in ioctl processing
Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the
function retrieve_status:
1. The code in retrieve_status checks that the output string fits into
the output buffer and writes the output string there
2. Then, the code aligns the "outptr" variable to the next 8-byte
boundary:
outptr = align_ptr(outptr);
3. The alignment doesn't check overflow, so outptr could point past the
buffer end
4. The "for" loop is iterated again, it executes:
remaining = len - (outptr - outbuf);
5. If "outptr" points past "outbuf + len", the arithmetics wraps around
and the variable "remaining" contains unusually high number
6. With "remaining" being high, the code writes more data past the end of
the buffer
Luckily, this bug has no security implications because:
1. Only root can issue device mapper ioctls
2. The commonly used libraries that communicate with device mapper
(libdevmapper and devicemapper-rs) use buffer size that is aligned to
8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input
buffer and the bug can't happen accidentally
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix zero-size GDS range init on RDNA4
RDNA4 (GFX 12) hardware removes the GDS, GWS, and OA on-chip memory
resources. The gfx_v12_0 initialisation code correctly leaves
adev->gds.gds_size, adev->gds.gws_size, and adev->gds.oa_size at
zero to reflect this.
amdgpu_ttm_init() unconditionally calls amdgpu_ttm_init_on_chip() for
each of these resources regardless of size. When the size is zero,
amdgpu_ttm_init_on_chip() forwards the call to ttm_range_man_init(),
which calls drm_mm_init(mm, 0, 0). drm_mm_init() immediately fires
DRM_MM_BUG_ON(start + size <= start) -- trivially true when size is
zero -- crashing the kernel during modprobe of amdgpu on an RX 9070 XT.
Guard against this by returning 0 early from
amdgpu_ttm_init_on_chip() when size_in_page is zero. This skips TTM
resource manager registration for hardware resources that are absent,
without affecting any other GPU type.
DRM_MM_BUG_ON() only asserts if CONFIG_DRM_DEBUG_MM is enabled in
the kernel config. This is apparently rarely enabled as these chips
have been in the market for over a year and this issue was only reported
now.
Oops-Analysis: http://oops.fenrus.org/reports/bugzilla.korg/221376/report.html
(cherry picked from commit 5719ce5865279cad4fd5f01011fe037168503f2d)
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
drm/vkms: Convert to DRM's vblank timer
Replace vkms' vblank timer with the DRM implementation. The DRM
code is identical in concept, but differs in implementation.
Vblank timers are covered in vblank helpers and initializer macros,
so remove the corresponding hrtimer in struct vkms_output. The
vblank timer calls vkms' custom timeout code via handle_vblank_timeout
in struct drm_crtc_helper_funcs.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-08
In the Linux kernel, the following vulnerability has been resolved:
ibmveth: Disable GSO for packets with small MSS
Some physical adapters on Power systems do not support segmentation
offload when the MSS is less than 224 bytes. Attempting to send such
packets causes the adapter to freeze, stopping all traffic until
manually reset.
Implement ndo_features_check to disable GSO for packets with small MSS
values. The network stack will perform software segmentation instead.
The 224-byte minimum matches ibmvnic
commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks
on GSO packets")
which uses the same physical adapters in SEA configurations.
The issue occurs specifically when the hardware attempts to perform
segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets
(gso_segs == 1) do not trigger the problematic LSO code path and are
transmitted normally without segmentation.
Add an ndo_features_check callback to disable GSO when MSS < 224 bytes.
Also call vlan_features_check() to ensure proper handling of VLAN packets,
particularly QinQ (802.1ad) configurations where the hardware parser may
not support certain offload features.
Validated using iptables to force small MSS values. Without the fix,
the adapter freezes. With the fix, packets are segmented in software
and transmission succeeds. Comprehensive regression testing completedd
(MSS tests, performance, stability).
CVSS Score
8.6
EPSS Score
0.004
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP
Yizhou Zhao reported that simply having one RAW socket on protocol
IPPROTO_RAW (255) was dangerous.
socket(AF_INET, SOCK_RAW, 255);
A malicious incoming ICMP packet can set the protocol field to 255
and match this socket, leading to FNHE cache changes.
inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST")
pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner
"man 7 raw" states:
A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able
to send any IP protocol that is specified in the passed header.
Receiving of all IP protocols via IPPROTO_RAW is not possible
using raw sockets.
Make sure we drop these malicious packets.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
nfc: hci: shdlc: Stop timers and work before freeing context
llc_shdlc_deinit() purges SHDLC skb queues and frees the llc_shdlc
structure while its timers and state machine work may still be active.
Timer callbacks can schedule sm_work, and sm_work accesses SHDLC state
and the skb queues. If teardown happens in parallel with a queued/running
work item, it can lead to UAF and other shutdown races.
Stop all SHDLC timers and cancel sm_work synchronously before purging the
queues and freeing the context.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
power: supply: rt9455: Fix use-after-free in power_supply_changed()
Using the `devm_` variant for requesting IRQ _before_ the `devm_`
variant for allocating/registering the `power_supply` handle, means that
the `power_supply` handle will be deallocated/unregistered _before_ the
interrupt handler (since `devm_` naturally deallocates in reverse
allocation order). This means that during removal, there is a race
condition where an interrupt can fire just _after_ the `power_supply`
handle has been freed, *but* just _before_ the corresponding
unregistration of the IRQ handler has run.
This will lead to the IRQ handler calling `power_supply_changed()` with
a freed `power_supply` handle. Which usually crashes the system or
otherwise silently corrupts the memory...
Note that there is a similar situation which can also happen during
`probe()`; the possibility of an interrupt firing _before_ registering
the `power_supply` handle. This would then lead to the nasty situation
of using the `power_supply` handle *uninitialized* in
`power_supply_changed()`.
Fix this racy use-after-free by making sure the IRQ is requested _after_
the registration of the `power_supply` handle.
CVSS Score
8.4
EPSS Score
0.001
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
pstore/ram: fix buffer overflow in persistent_ram_save_old()
persistent_ram_save_old() can be called multiple times for the same
persistent_ram_zone (e.g., via ramoops_pstore_read -> ramoops_get_next_prz
for PSTORE_TYPE_DMESG records).
Currently, the function only allocates prz->old_log when it is NULL,
but it unconditionally updates prz->old_log_size to the current buffer
size and then performs memcpy_fromio() using this new size. If the
buffer size has grown since the first allocation (which can happen
across different kernel boot cycles), this leads to:
1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls
2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer
using the incorrect (larger) old_log_size
The KASAN splat would look similar to:
BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x...
Read of size N at addr ... by task ...
The conditions are likely extremely hard to hit:
0. Crash with a ramoops write of less-than-record-max-size bytes.
1. Reboot: ramoops registers, pstore_get_records(0) reads old crash,
allocates old_log with size X
2. Crash handler registered, timer started (if pstore_update_ms >= 0)
3. Oops happens (non-fatal, system continues)
4. pstore_dump() writes oops via ramoops_pstore_write() size Y (>X)
5. pstore_new_entry = 1, pstore_timer_kick() called
6. System continues running (not a panic oops)
7. Timer fires after pstore_update_ms milliseconds
8. pstore_timefunc() → schedule_work() → pstore_dowork() → pstore_get_records(1)
9. ramoops_get_next_prz() → persistent_ram_save_old()
10. buffer_size() returns Y, but old_log is X bytes
11. Y > X: memcpy_fromio() overflows heap
Requirements:
- a prior crash record exists that did not fill the record size
(almost impossible since the crash handler writes as much as it
can possibly fit into the record, capped by max record size and
the kmsg buffer almost always exceeds the max record size)
- pstore_update_ms >= 0 (disabled by default)
- Non-fatal oops (system survives)
Free and reallocate the buffer when the new size differs from the
previously allocated size. This ensures old_log always has sufficient
space for the data being copied.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
AppArmor: Allow apparmor to handle unaligned dfa tables
The dfa tables can originate from kernel or userspace and 8-byte alignment
isn't always guaranteed and as such may trigger unaligned memory accesses
on various architectures. Resulting in the following
[ 73.901376] WARNING: CPU: 0 PID: 341 at security/apparmor/match.c:316 aa_dfa_unpack+0x6cc/0x720
[ 74.015867] Modules linked in: binfmt_misc evdev flash sg drm drm_panel_orientation_quirks backlight i2c_core configfs nfnetlink autofs4 ext4 crc16 mbcache jbd2 hid_generic usbhid sr_mod hid cdrom
sd_mod ata_generic ohci_pci ehci_pci ehci_hcd ohci_hcd pata_ali libata sym53c8xx scsi_transport_spi tg3 scsi_mod usbcore libphy scsi_common mdio_bus usb_common
[ 74.428977] CPU: 0 UID: 0 PID: 341 Comm: apparmor_parser Not tainted 6.18.0-rc6+ #9 NONE
[ 74.536543] Call Trace:
[ 74.568561] [<0000000000434c24>] dump_stack+0x8/0x18
[ 74.633757] [<0000000000476438>] __warn+0xd8/0x100
[ 74.696664] [<00000000004296d4>] warn_slowpath_fmt+0x34/0x74
[ 74.771006] [<00000000008db28c>] aa_dfa_unpack+0x6cc/0x720
[ 74.843062] [<00000000008e643c>] unpack_pdb+0xbc/0x7e0
[ 74.910545] [<00000000008e7740>] unpack_profile+0xbe0/0x1300
[ 74.984888] [<00000000008e82e0>] aa_unpack+0xe0/0x6a0
[ 75.051226] [<00000000008e3ec4>] aa_replace_profiles+0x64/0x1160
[ 75.130144] [<00000000008d4d90>] policy_update+0xf0/0x280
[ 75.201057] [<00000000008d4fc8>] profile_replace+0xa8/0x100
[ 75.274258] [<0000000000766bd0>] vfs_write+0x90/0x420
[ 75.340594] [<00000000007670cc>] ksys_write+0x4c/0xe0
[ 75.406932] [<0000000000767174>] sys_write+0x14/0x40
[ 75.472126] [<0000000000406174>] linux_sparc_syscall+0x34/0x44
[ 75.548802] ---[ end trace 0000000000000000 ]---
[ 75.609503] dfa blob stream 0xfff0000008926b96 not aligned.
[ 75.682695] Kernel unaligned access at TPC[8db2a8] aa_dfa_unpack+0x6e8/0x720
Work around it by using the get_unaligned_xx() helpers.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-03