Home / CVEs
CVE Database
Published vulnerabilities with severity, known exploitation and official sources.
CVE-2026-46110
High · 7.5
CWE-476 May 28, 2026
net: stmmac: Prevent NULL deref when RX memory exhausted
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Prevent NULL deref when RX memory exhausted
The CPU receives frames from the MAC through conventional DMA: the CPU
allocates buffers for the MAC, then the MAC fills them and returns
ownership to the CPU. For each hardware RX queue, the CPU and MAC
coordinate through a shared ring array of DMA descriptors: one
descriptor per DMA buffer. Each descriptor includes the buffer's
physical address and a status flag ("OWN") indicating which side owns
the buffer: OWN=0 for CPU, OWN=1 for MAC. The CPU is only allowed to set
the flag and the MAC is only allowed to clear it, and both must move
through the ring in sequence: thus the ring is used for both
"submissions" and "completions."
In the stmmac driver, stmmac_rx() bookmarks its position in the ring
with the `cur_rx` index. The main receive loop in that function checks
for rx_descs[cur_rx].own=0, gives the corresponding buffer to the
network stack (NULLing the pointer), and increments `cur_rx` modulo the
ring size. After the loop exits, stmmac_rx_refill(), which bookmarks its
position with `dirty_rx`, allocates fresh buffers and rearms the
descriptors (setting OWN=1). If it fails any allocation, it simply stops
early (leaving OWN=0) and will retry where it left off when next called.
This means descriptors have a three-stage lifecycle (terms my own):
- `empty` (OWN=1, buffer valid)
- `full` (OWN=0, buffer valid and populated)
- `dirty` (OWN=0, buffer NULL)
But because stmmac_rx() only checks OWN, it confuses `full`/`dirty`. In
the past (see 'Fixes:'), there was a bug where the loop could cycle
`cur_rx` all the way back to the first descriptor it dirtied, resulting
in a NULL dereference when mistaken for `full`. The aforementioned
commit resolved that *specific* failure by capping the loop's iteration
limit at `dma_rx_size - 1`, but this is only a partial fix: if the
previous stmmac_rx_refill() didn't complete, then there are leftover
`dirty` descriptors that the loop might encounter without needing to
cycle fully around. The current code therefore panics (see 'Closes:')
when stmmac_rx_refill() is memory-starved long enough for `cur_rx` to
catch up to `dirty_rx`.
Fix this by explicitly checking, before advancing `cur_rx`, if the next
entry is dirty; exit the loop if so. This prevents processing of the
final, used descriptor until stmmac_rx_refill() succeeds, but
fully prevents the `cur_rx == dirty_rx` ambiguity as the previous bugfix
intended: so remove the clamp as well. Since stmmac_rx_zc() is a
copy-paste-and-tweak of stmmac_rx() and the code structure is identical,
any fix to stmmac_rx() will also need a corresponding fix for
stmmac_rx_zc(). Therefore, apply the same check there.
In stmmac_rx() (not stmmac_rx_zc()), a related bug remains: after the
MAC sets OWN=0 on the final descriptor, it will be unable to send any
further DMA-complete IRQs until it's given more `empty` descriptors.
Currently, the driver simply *hopes* that the next stmmac_rx_refill()
succeeds, risking an indefinite stall of the receive process if not. But
this is not a regression, so it can be addressed in a future change.
CVE-2026-44710
Medium · 4.6
CWE-476 May 27, 2026
pam_usb: NULL pointer dereference from UDisks device fields causes PAM crash and login denial-of-service
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/device.c passed the return values of udisks_drive_get_serial(), udisks_drive_get_vendor(), and udisks_drive_get_model() directly to strcmp() without NULL checks. The GIO/UDisks API documentation states these accessors can return NULL for devices that do not expose the corresponding field. Passing NULL to strcmp() is undefined behaviour (typically a SIGSEGV). This vulnerability is fixed in 0.8.7.
CVE-2026-9759
Medium · 5.5
CWE-476 May 27, 2026
NULL Pointer Dereference in Wireshark
ROHC protocol dissector crash in Wireshark 4.6.0 to 4.6.5 and 4.4.0 to 4.4.15 allows denial of service
CVE-2026-8360
High · 7.5
CWE-476 May 27, 2026
Gladinet Triofox Unchecked Return Value to NULL Pointer Dereference DOS
Function calls to WOSCommonUtil.dll!WOSSysInfoGetDeviceInterface() in various DLLs (i.e., WOSProfileMgrModule.dll, WOSWebDavModule.dll) can return a NULL pointer (i.e., when no user is logged into the Triofox Server Agent Management Console). The returned NULL pointer is not checked before being dereferenced.
CVE-2026-8359
High · 7.5
CWE-476 May 27, 2026
Gladinet Triofox WOSHttpStatusModule.dll NULL Function Pointer Call DoS
When processing a request with a URL path starting with /status or /sysinfo, WOSHttpStatusModule.dll is to be loaded to handle such URL patterns. The WOSBin_LoadHttpModule function in the dll would be called to set up a "module" object for that module. However, WOSHttpStatusModule.dll is not present in the installation. As a result, a function pointer to WOSBin_LoadHttpModule (which would have been in the export table in WOSHttpStatusModule.dll) is set to NULL, resulting in calling a function at address 0.
CVE-2026-47271
Medium · 5.1
CWE-476 May 27, 2026
pam_usb: OOM guards removed by -DNDEBUG cause NULL dereference and authentication process crash
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, src/mem.c implemented out-of-memory guards for xmalloc(), xrealloc(), and xstrdup() using assert(data != NULL). The C standard specifies that all assert() expressions are compiled out when NDEBUG is defined at build time. NDEBUG is commonly defined in release and packaging builds (Debian, Fedora, Arch package flags all define it via -DNDEBUG in CFLAGS). With the guard removed, xmalloc/xrealloc/xstrdup silently return NULL on allocation failure. Every caller in the codebase dereferences the return value without a NULL check -- this is the intended design, as the guard was supposed to abort before the dereference. With the guard gone, any allocation failure causes a NULL pointer dereference, crashing the PAM module. A crash in a PAM module loaded by sudo or login causes authentication to fail for the duration of the crash, creating a local denial-of-service condition. An attacker who can induce memory pressure at authentication time can lock all users out of sudo and login. This vulnerability is fixed in 0.9.0.
CVE-2026-45104
High · 7.5
CWE-476 May 27, 2026
MapServer: NULL pointer dereference in SLD `<ElseFilter>` rule parsing reachable via WMS `SLD_BODY`
MapServer is a system for developing web-based GIS applications. From 6.4.0 to before 8.6.3, msSLDParseUserStyle always calls _SLDApplyRuleValues(psRule, psLayer, 1); for any <Rule> carrying <ElseFilter/> — it assumes msSLDParseRule added one class. When the rule has no symbolizer (a structurally valid SLD), msSLDParseRule adds zero, and _SLDApplyRuleValues ends up indexing _class[-1], resulting in a NULL pointer dereference. A 200-byte well-formed SLD via the WMS SLD_BODY= parameter is enough to trigger this, no auth required. This vulnerability is fixed in 8.6.3.
CVE-2026-44323
Medium · 6.5
CWE-476 May 27, 2026
free5GC: UDR nudr-dr DELETE amf-subscriptions panics on missing subsId when UE state exists (nil pointer dereference)
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler contains a nil-pointer dereference reachable from a single authenticated request, after one preparatory authenticated EE-subscription create. The handler checks _, ok = UESubsData.EeSubscriptionCollection[subsId] and sets a 404 problem-details on the miss path, but then continues to UESubsData.EeSubscriptionCollection[subsId].AmfSubscriptionInfos -- dereferencing the same missing entry instead of returning. Gin recovery converts the panic into HTTP 500, but the endpoint remains repeatedly panicable. This vulnerability is fixed in 4.2.2.
CVE-2026-44322
High · 7.5
CWE-476 May 27, 2026
free5GC: NEF 3gpp-pfd-management PATCH applications/{appId} panics on UDR access failure due to nil ProblemDetails dereference
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF PATCH /3gpp-pfd-management/v1/{afId}/transactions/{transId}/applications/{appId} handler panics with a nil-pointer dereference when the upstream UDR call fails AND the consumer wrapper returns err != nil together with a nil *ProblemDetails. The handler's errPfdData != nil branch builds its own problemDetailsErr correctly, but immediately after it reads problemDetails.Cause (the OTHER value, which is nil in this branch) and panics. Gin recovery converts the panic into HTTP 500, so a single PATCH against this endpoint returns 500 instead of the intended controlled error response whenever UDR access is failing. This vulnerability is fixed in 4.2.2.
CVE-2026-44317
Medium · 6.5
CWE-476 May 27, 2026
free5GC: PCF npcf-policyauthorization POST /app-sessions panics on suppFeat=1 with missing AfRoutReq via nil pointer dereference
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's PCF POST /npcf-policyauthorization/v1/app-sessions handler panics on a single authenticated request whose ascReqData.suppFeat == "1" (enabling traffic-routing feature negotiation) and whose medComponents entries supply an afAppId but NO AfRoutReq. The create path then calls provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, ...) with routeReq == nil and dereferences routeReq.RouteToLocs (and other fields) without a nil check, causing runtime error: invalid memory address or nil pointer dereference. Gin recovery converts the panic into HTTP 500. This vulnerability is fixed in 4.2.2.
CVE-2026-44316
High · 7.5
CWE-476 May 27, 2026
free5GC: PCF npcf-smpolicycontrol POST /sm-policies panics on downstream UDR/OpenAPI 404 via nil pointer dereference
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's PCF POST /npcf-smpolicycontrol/v1/sm-policies handler (HandleCreateSmPolicyRequest) panics with a nil-pointer dereference when a downstream OpenAPI consumer call (UDR lookup) returns 404 Not Found and the consumer wrapper returns err != nil together with a nil response struct. The handler logs the OpenAPI error and continues executing instead of returning, then dereferences the nil response struct on a subsequent line and panics. Gin recovery converts the panic into HTTP 500, so a single attacker-shaped POST returns 500 instead of a clean 4xx whenever the downstream lookup fails. The PCF process keeps running. The trigger is a single POST containing input that causes the downstream UDR lookup to fail (e.g. an unknown DNN). In 4.2.1 this endpoint is also reachable WITHOUT an Authorization header because the PCF Npcf_SMPolicyControl route group is mounted without inbound auth middleware. This vulnerability is fixed in 4.2.2.
CVE-2025-70116
Medium · 4.3
CWE-476 May 27, 2026
A NULL pointer dereference in GPAC MP4Box: when parsing certain truncated MP4 files, an…
A NULL pointer dereference in GPAC MP4Box: when parsing certain truncated MP4 files, an unknown/invalid stsd entry can result in missing descriptor fields (e.g., codec/mime/profile strings). gf_media_map_esd then calls strlen() on a NULL pointer, triggering a crash (ASan SEGV).
CVE-2026-8180
High · 7.5
CWE-476 May 27, 2026
Multiple vulnerabilities in Aspera applications.
IBM Aspera High-Speed Transfer Endpoint 3.7.4 through 4.4.7 Fix Pack 1 and IBM Aspera High-Speed Transfer Server 3.7.4 through 4.4.7 Fix Pack 1 and IBM Aspera High-Speed Transfer Endpoint are affected by a potential denial of service in the asperahttpd component. An unauthenticated user can cause the asperahttpd service to crash.
CVE-2026-46098
Medium · 5.5
CWE-476 May 27, 2026
net: caif: clear client service pointer on teardown
In the Linux kernel, the following vulnerability has been resolved:
net: caif: clear client service pointer on teardown
`caif_connect()` can tear down an existing client after remote shutdown by
calling `caif_disconnect_client()` followed by `caif_free_client()`.
`caif_free_client()` releases the service layer referenced by
`adap_layer->dn`, but leaves that pointer stale.
When the socket is later destroyed, `caif_sock_destructor()` calls
`caif_free_client()` again and dereferences the freed service pointer.
Clear the client/service links before releasing the service object so
repeated teardown becomes harmless.
CVE-2026-46092
Medium · 5.5
CWE-476 May 27, 2026
wifi: rtw88: check for PCI upstream bridge existence
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw88: check for PCI upstream bridge existence
pci_upstream_bridge() returns NULL if the device is on a root bus. If
8821CE is installed in the system with such a PCI topology, the probing
routine will crash. This has probably been unnoticed as 8821CE is mostly
supplied in laptops where there is a PCI-to-PCI bridge located upstream
from the device. However the card might be installed on a system with
different configuration.
Check if the bridge does exist for the specific workaround to be applied.
Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.
CVE-2026-46086
Medium · 5.5
CWE-476 May 27, 2026
net: bridge: use a stable FDB dst snapshot in RCU readers
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: use a stable FDB dst snapshot in RCU readers
Local FDB entries can be rewritten in place by `fdb_delete_local()`, which
updates `f->dst` to another port or to `NULL` while keeping the entry
alive. Several bridge RCU readers inspect `f->dst`, including
`br_fdb_fillbuf()` through the `brforward_read()` sysfs path.
These readers currently load `f->dst` multiple times and can therefore
observe inconsistent values across the check and later dereference.
In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change
`f->dst` after the NULL check and before the `port_no` dereference,
leading to a NULL-ptr-deref.
Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each
affected RCU reader and using that snapshot for the rest of the access
sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()`
with `WRITE_ONCE()` so the readers and writer use matching access patterns.
CVE-2026-46079
Medium · 5.5
CWE-476 May 27, 2026
rbd: fix null-ptr-deref when device_add_disk() fails
In the Linux kernel, the following vulnerability has been resolved:
rbd: fix null-ptr-deref when device_add_disk() fails
do_rbd_add() publishes the device with device_add() before calling
device_add_disk(). If device_add_disk() fails after device_add()
succeeds, the error path calls rbd_free_disk() directly and then later
falls through to rbd_dev_device_release(), which calls rbd_free_disk()
again. This double teardown can leave blk-mq cleanup operating on
invalid state and trigger a null-ptr-deref in
__blk_mq_free_map_and_rqs(), reached from blk_mq_free_tag_set().
Fix this by following the normal remove ordering: call device_del()
before rbd_dev_device_release() when device_add_disk() fails after
device_add(). That keeps the teardown sequence consistent and avoids
re-entering disk cleanup through the wrong path.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available.
We reproduced the bug on v7.0 with a real Ceph backend and a QEMU x86_64
guest booted with KASAN and CONFIG_FAILSLAB enabled. The reproducer
confines failslab injections to the __add_disk() range and injects
fail-nth while mapping an RBD image through
/sys/bus/rbd/add_single_major.
On the unpatched kernel, fail-nth=4 reliably triggered the fault:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 273 Comm: bash Not tainted 7.0.0-01247-gd60bc1401583 #6 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__blk_mq_free_map_and_rqs+0x8c/0x240
Code: 00 00 48 8b 6b 60 41 89 f4 49 c1 e4 03 4c 01 e5 45 85 ed 0f 85 0a 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 e9 48 c1 e9 03 <80> 3c 01 00 0f 85 31 01 00 00 4c 8b 6d 00 4d 85 ed 0f 84 e2 00 00
RSP: 0018:ff1100000ab0fac8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ff1100000c4806a0 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ff1100000c4806f4
RBP: 0000000000000000 R08: 0000000000000001 R09: ffe21c000189001b
R10: ff1100000c4800df R11: ff1100006cf37be0 R12: 0000000000000000
R13: 0000000000000000 R14: ff1100000c480700 R15: ff1100000c480004
FS: 00007f0fbe8fe740(0000) GS:ff110000e5851000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe53473b2e0 CR3: 0000000012eef000 CR4: 00000000007516f0
PKRU: 55555554
Call Trace:
<TASK>
blk_mq_free_tag_set+0x77/0x460
do_rbd_add+0x1446/0x2b80
? __pfx_do_rbd_add+0x10/0x10
? lock_acquire+0x18c/0x300
? find_held_lock+0x2b/0x80
? sysfs_file_kobj+0xb6/0x1b0
? __pfx_sysfs_kf_write+0x10/0x10
kernfs_fop_write_iter+0x2f4/0x4a0
vfs_write+0x98e/0x1000
? expand_files+0x51f/0x850
? __pfx_vfs_write+0x10/0x10
ksys_write+0xf2/0x1d0
? __pfx_ksys_write+0x10/0x10
do_syscall_64+0x115/0x690
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fbea15907
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffe22346ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f0fbea15907
RDX: 0000000000000058 RSI: 0000563ace6c0ef0 RDI: 0000000000000001
RBP: 0000563ace6c0ef0 R08: 0000563ace6c0ef0 R09: 6b6435726d694141
R10: 5250337279762f78 R11: 0000000000000246 R12: 0000000000000058
R13: 00007f0fbeb1c780 R14: ff1100000c480700 R15: ff1100000c480004
</TASK>
With this fix applied, rerunning the reproducer over fail-nth=1..256
yields no KASAN reports.
[ idryomov: rename err_out_device_del -> err_out_device ]
CVE-2026-46034
Medium · 5.5
CWE-476 May 27, 2026
vfio/cdx: Fix NULL pointer dereference in interrupt trigger path
In the Linux kernel, the following vulnerability has been resolved:
vfio/cdx: Fix NULL pointer dereference in interrupt trigger path
Add validation to ensure MSI is configured before accessing cdx_irqs
array in vfio_cdx_set_msi_trigger(). Without this check, userspace
can trigger a NULL pointer dereference by calling VFIO_DEVICE_SET_IRQS
with VFIO_IRQ_SET_DATA_BOOL or VFIO_IRQ_SET_DATA_NONE flags before
ever setting up interrupts via VFIO_IRQ_SET_DATA_EVENTFD.
The vfio_cdx_msi_enable() function allocates the cdx_irqs array and
sets config_msi to 1 only when called through the EVENTFD path. The
trigger loop (for DATA_BOOL/DATA_NONE) assumed this had already been
done, but there was no enforcement of this call ordering.
This matches the protection used in the PCI VFIO driver where
vfio_pci_set_msi_trigger() checks irq_is() before the trigger loop.
CVE-2026-46024
High · 7.5
CWE-476 May 27, 2026
libceph: Prevent potential null-ptr-deref in ceph_handle_auth_reply()
In the Linux kernel, the following vulnerability has been resolved:
libceph: Prevent potential null-ptr-deref in ceph_handle_auth_reply()
If a message of type CEPH_MSG_AUTH_REPLY contains a zero value for both
protocol and result, this is currently not treated as an error. In case
of ac->negotiating == true and ac->protocol > 0, this leads to setting
ac->protocol = 0 and ac->ops = NULL. Thereafter, the check for
ac->protocol != protocol returns false, and init_protocol() is not
called. Subsequently, ac->ops->handle_reply() is called, which leads to
a null pointer dereference, because ac->ops is still NULL.
This patch changes the check for ac->protocol != protocol to
!ac->protocol, as this also includes the case when the protocol was set
to zero in the message. This causes the message to be treated as
containing a bad auth protocol.
CVE-2026-46016
Medium · 5.5
CWE-476 May 27, 2026
remoteproc: xlnx: Only access buffer information if IPI is buffered
In the Linux kernel, the following vulnerability has been resolved:
remoteproc: xlnx: Only access buffer information if IPI is buffered
In the receive callback check if message is NULL to prevent
possibility of crash by NULL pointer dereferencing.
CVE-2026-45982
Medium · 5.5
CWE-476 May 27, 2026
ACPICA: Fix NULL pointer dereference in acpi_ev_address_space_dispatch()
In the Linux kernel, the following vulnerability has been resolved:
ACPICA: Fix NULL pointer dereference in acpi_ev_address_space_dispatch()
Cover a missed execution path with a new check.
CVE-2026-45978
Medium · 5.5
CWE-476 May 27, 2026
staging: greybus: lights: avoid NULL deref
In the Linux kernel, the following vulnerability has been resolved:
staging: greybus: lights: avoid NULL deref
gb_lights_light_config() stores channel_count before allocating the
channels array. If kcalloc() fails, gb_lights_release() iterates the
non-zero count and dereferences light->channels, which is NULL.
Allocate channels first and only then publish channels_count so the
cleanup path can't walk a NULL pointer.
CVE-2026-45969
Medium · 5.5
CWE-476 May 27, 2026
HID: playstation: Add missing check for input_ff_create_memless
In the Linux kernel, the following vulnerability has been resolved:
HID: playstation: Add missing check for input_ff_create_memless
The ps_gamepad_create() function calls input_ff_create_memless()
without verifying its return value, which can lead to incorrect
behavior or potential crashes when FF effects are triggered.
Add a check for the return value of input_ff_create_memless().
CVE-2026-45968
Medium · 5.5
CWE-476 May 27, 2026
cpuidle: Skip governor when only one idle state is available
In the Linux kernel, the following vulnerability has been resolved:
cpuidle: Skip governor when only one idle state is available
On certain platforms (PowerNV systems without a power-mgt DT node),
cpuidle may register only a single idle state. In cases where that
single state is a polling state (state 0), the ladder governor may
incorrectly treat state 1 as the first usable state and pass an
out-of-bounds index. This can lead to a NULL enter callback being
invoked, ultimately resulting in a system crash.
[ 13.342636] cpuidle-powernv : Only Snooze is available
[ 13.351854] Faulting instruction address: 0x00000000
[ 13.376489] NIP [0000000000000000] 0x0
[ 13.378351] LR [c000000001e01974] cpuidle_enter_state+0x2c4/0x668
Fix this by adding a bail-out in cpuidle_select() that returns state 0
directly when state_count <= 1, bypassing the governor and keeping the
tick running.
CVE-2026-45966
Medium · 5.5
CWE-476 May 27, 2026
apparmor: fix NULL pointer dereference in __unix_needs_revalidation
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix NULL pointer dereference in __unix_needs_revalidation
When receiving file descriptors via SCM_RIGHTS, both the socket pointer
and the socket's sk pointer can be NULL during socket setup or teardown,
causing NULL pointer dereferences in __unix_needs_revalidation().
This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new
__unix_needs_revalidation() function was added without proper NULL checks.
The crash manifests as:
BUG: kernel NULL pointer dereference, address: 0x0000000000000018
RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0)
Call Trace:
apparmor_file_receive+0x42/0x80
security_file_receive+0x2e/0x50
receive_fd+0x1d/0xf0
scm_detach_fds+0xad/0x1c0
The function dereferences sock->sk->sk_family without checking if either
sock or sock->sk is NULL first.
Add NULL checks for both sock and sock->sk before accessing sk_family.