Linux: >> Linux Kernel >> 4.20.4 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix dc_link NULL handling in HPD init
amdgpu_dm_hpd_init() may see connectors without a valid dc_link.
The code already checks dc_link for the polling decision, but later
unconditionally dereferences it when setting up HPD interrupts.
Assign dc_link early and skip connectors where it is NULL.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c:940 amdgpu_dm_hpd_init()
error: we previously assumed 'dc_link' could be null (see line 931)
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c
923 /*
924 * Analog connectors may be hot-plugged unlike other connector
925 * types that don't support HPD. Only poll analog connectors.
926 */
927 use_polling |=
928 amdgpu_dm_connector->dc_link &&
^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The patch adds this NULL check but hopefully it can be removed
929 dc_connector_supports_analog(amdgpu_dm_connector->dc_link->link_id.id);
930
931 dc_link = amdgpu_dm_connector->dc_link;
dc_link assigned here.
932
933 /*
934 * Get a base driver irq reference for hpd ints for the lifetime
935 * of dm. Note that only hpd interrupt types are registered with
936 * base driver; hpd_rx types aren't. IOW, amdgpu_irq_get/put on
937 * hpd_rx isn't available. DM currently controls hpd_rx
938 * explicitly with dc_interrupt_set()
939 */
--> 940 if (dc_link->irq_source_hpd != DC_IRQ_SOURCE_INVALID) {
^^^^^^^^^^^^^^^^^^^^^^^ If it's NULL then we are trouble because we dereference it here.
941 irq_type = dc_link->irq_source_hpd - DC_IRQ_SOURCE_HPD1;
942 /*
943 * TODO: There's a mismatch between mode_info.num_hpd
944 * and what bios reports as the # of connectors with hpd
CVSS Score
5.5
EPSS Score
0.0
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gfx3d: add parent to parent request map
After commit d228ece36345 ("clk: divider: remove round_rate() in favor
of determine_rate()") determining GFX3D clock rate crashes, because the
passed parent map doesn't provide the expected best_parent_hw clock
(with the roundd_rate path before the offending commit the
best_parent_hw was ignored).
Set the field in parent_req in addition to setting it in the req,
fixing the crash.
clk_hw_round_rate (drivers/clk/clk.c:1764) (P)
clk_divider_bestdiv (drivers/clk/clk-divider.c:336)
divider_determine_rate (drivers/clk/clk-divider.c:358)
clk_alpha_pll_postdiv_determine_rate (drivers/clk/qcom/clk-alpha-pll.c:1275)
clk_core_determine_round_nolock (drivers/clk/clk.c:1606)
clk_core_round_rate_nolock (drivers/clk/clk.c:1701)
__clk_determine_rate (drivers/clk/clk.c:1741)
clk_gfx3d_determine_rate (drivers/clk/qcom/clk-rcg2.c:1268)
clk_core_determine_round_nolock (drivers/clk/clk.c:1606)
clk_core_round_rate_nolock (drivers/clk/clk.c:1701)
clk_core_round_rate_nolock (drivers/clk/clk.c:1710)
clk_round_rate (drivers/clk/clk.c:1804)
dev_pm_opp_set_rate (drivers/opp/core.c:1440 (discriminator 1))
msm_devfreq_target (drivers/gpu/drm/msm/msm_gpu_devfreq.c:51)
devfreq_set_target (drivers/devfreq/devfreq.c:360)
devfreq_update_target (drivers/devfreq/devfreq.c:426)
devfreq_monitor (drivers/devfreq/devfreq.c:458)
process_one_work (arch/arm64/include/asm/jump_label.h:36 include/trace/events/workqueue.h:110 kernel/workqueue.c:3284)
worker_thread (kernel/workqueue.c:3356 (discriminator 2) kernel/workqueue.c:3443 (discriminator 2))
kthread (kernel/kthread.c:467)
ret_from_fork (arch/arm64/kernel/entry.S:861)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-06-03
In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject userspace cifs.spnego descriptions
cifs.spnego key descriptions contain authority-bearing fields such as
pid, uid, creduid, and upcall_target that cifs.upcall treats as
kernel-originating inputs. However, userspace can also create keys of
this type through request_key(2) or add_key(2), allowing those fields to
be supplied without CIFS origin.
Only accept cifs.spnego descriptions while CIFS is using its private
spnego_cred to request the key.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-06-01
In the Linux kernel, the following vulnerability has been resolved:
media: saa7164: add ioremap return checks and cleanups
Add checks for ioremap return values in saa7164_dev_setup(). If
ioremap for BAR0 or BAR2 fails, release the already allocated PCI
memory regions, remove the device from the global list, decrement
the device count, and return -ENODEV.
This prevents potential null pointer dereferences and ensures proper
cleanup on memory mapping failures.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: stop caching unowned originator pointers in BAT IV
BAT IV keeps the last-hop neighbor address in each neigh_node, but some
paths also cache an originator pointer derived from a temporary lookup.
That pointer is not owned by the neigh_node and may no longer refer to a
live originator entry after purge handling runs.
Stop storing the auxiliary originator pointer in the BAT IV neighbor
state. When BAT IV needs the neighbor originator data, resolve it from
the stored neighbor address and drop the reference again after use.
[sven: avoid bonding logic for outgoing OGM]
CVSS Score
8.8
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
spi: mpc52xx: fix use-after-free on registration failure
Make sure to disable and free the interrupts in case controller
registration fails to avoid a potential use-after-free and resource
leak.
This issue was flagged by Sashiko when reviewing a controller
deregistration fix.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
spi: rspi: fix controller deregistration
Make sure to deregister the controller before releasing underlying
resources like DMA during driver unbind.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
spi: fsl: fix controller deregistration
Make sure to deregister the controller before releasing underlying
resources like DMA during driver unbind.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL
The SCTP_SENDALL path in sctp_sendmsg() iterates ep->asocs with
list_for_each_entry_safe(), which caches the next entry in @tmp before
the loop body runs. The body calls sctp_sendmsg_to_asoc(), which may
drop the socket lock inside sctp_wait_for_sndbuf().
While the lock is dropped, another thread can SCTP_SOCKOPT_PEELOFF the
association cached in @tmp, migrating it to a new endpoint via
sctp_sock_migrate() (list_del_init() + list_add_tail() to
newep->asocs), and optionally close the new socket which frees the
association via kfree_rcu(). The cached @tmp can also be freed by a
network ABORT for that association, processed in softirq while the
lock is dropped.
sctp_wait_for_sndbuf() revalidates @asoc (the current entry) on re-lock
via the "sk != asoc->base.sk" and "asoc->base.dead" checks, but nothing
revalidates @tmp. After a successful return, the iterator advances to
the stale @tmp, yielding either a use-after-free (if the peeled socket
was closed) or a list-walk onto the new endpoint's list head (type
confusion of &newep->asocs as a struct sctp_association *).
Both are reachable from CapEff=0; the type-confusion path gives
controlled indirect call via the outqueue.sched->init_sid pointer.
Fix by re-deriving @tmp from @asoc after sctp_sendmsg_to_asoc()
returns. @asoc is known to still be on ep->asocs at that point: the
only callers that list_del an association from ep->asocs are
sctp_association_free() (which sets asoc->base.dead) and
sctp_assoc_migrate() (which changes asoc->base.sk), and
sctp_wait_for_sndbuf() checks both under the lock before any
successful return; a tripped check propagates as err < 0 and the loop
bails before the re-derive.
The SCTP_ABORT path in sctp_sendmsg_check_sflags() returns 0 and the
loop hits 'continue' before sctp_sendmsg_to_asoc() is ever called, so
the @tmp cached by list_for_each_entry_safe() still covers the
lock-held free that ba59fb027307 ("sctp: walk the list of asoc
safely") was added for.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: put backbone reference on failed claim hash insert
When batadv_bla_add_claim() fails to insert a new claim into the hash, it
leaked a reference to the backbone_gw for which the claim was intended.
Call batadv_backbone_gw_put() on the error path to release the reference
and avoid leaking the backbone_gw object.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-28