Linux: >> Linux Kernel >> 2.6.20.18 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
l2tp: prevent possible tunnel refcount underflow
When a session is created, it sets a backpointer to its tunnel. When
the session refcount drops to 0, l2tp_session_free drops the tunnel
refcount if session->tunnel is non-NULL. However, session->tunnel is
set in l2tp_session_create, before the tunnel refcount is incremented
by l2tp_session_register, which leaves a small window where
session->tunnel is non-NULL when the tunnel refcount hasn't been
bumped.
Moving the assignment to l2tp_session_register is trivial but
l2tp_session_create calls l2tp_session_set_header_len which uses
session->tunnel to get the tunnel's encap. Add an encap arg to
l2tp_session_set_header_len to avoid using session->tunnel.
If l2tpv3 sessions have colliding IDs, it is possible for
l2tp_v3_session_get to race with l2tp_session_register and fetch a
session which doesn't yet have session->tunnel set. Add a check for
this case.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for head_pipe in dcn32_acquire_idle_pipe_for_head_pipe_in_layer
This commit addresses a potential null pointer dereference issue in the
`dcn32_acquire_idle_pipe_for_head_pipe_in_layer` function. The issue
could occur when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn32/dcn32_resource.c:2690 dcn32_acquire_idle_pipe_for_head_pipe_in_layer() error: we previously assumed 'head_pipe' could be null (see line 2681)
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for head_pipe in dcn201_acquire_free_pipe_for_layer
This commit addresses a potential null pointer dereference issue in the
`dcn201_acquire_free_pipe_for_layer` function. The issue could occur
when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn201/dcn201_resource.c:1016 dcn201_acquire_free_pipe_for_layer() error: we previously assumed 'head_pipe' could be null (see line 1010)
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointers before multiple uses
[WHAT & HOW]
Poniters, such as stream_enc and dc->bw_vbios, are null checked previously
in the same function, so Coverity warns "implies that stream_enc and
dc->bw_vbios might be null". They are used multiple times in the
subsequent code and need to be checked.
This fixes 10 FORWARD_NULL issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointers before used
[WHAT & HOW]
Poniters, such as dc->clk_mgr, are null checked previously in the same
function, so Coverity warns "implies that "dc->clk_mgr" might be null".
As a result, these pointers need to be checked when used again.
This fixes 10 FORWARD_NULL issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointers before using them
[WHAT & HOW]
These pointers are null checked previously in the same function,
indicating they might be null as reported by Coverity. As a result,
they need to be checked when used again.
This fixes 3 FORWARD_NULL issue reported by Coverity.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Pass non-null to dcn20_validate_apply_pipe_split_flags
[WHAT & HOW]
"dcn20_validate_apply_pipe_split_flags" dereferences merge, and thus it
cannot be a null pointer. Let's pass a valid pointer to avoid null
dereference.
This fixes 2 FORWARD_NULL issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
fbdev: efifb: Register sysfs groups through driver core
The driver core can register and cleanup sysfs groups already.
Make use of that functionality to simplify the error handling and
cleanup.
Also avoid a UAF race during unregistering where the sysctl attributes
were usable after the info struct was freed.
CVSS Score
5.5
EPSS Score
0.003
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
rcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb()
For kernels built with CONFIG_FORCE_NR_CPUS=y, the nr_cpu_ids is
defined as NR_CPUS instead of the number of possible cpus, this
will cause the following system panic:
smpboot: Allowing 4 CPUs, 0 hotplug CPUs
...
setup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:512 nr_node_ids:1
...
BUG: unable to handle page fault for address: ffffffff9911c8c8
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 15 Comm: rcu_tasks_trace Tainted: G W
6.6.21 #1 5dc7acf91a5e8e9ac9dcfc35bee0245691283ea6
RIP: 0010:rcu_tasks_need_gpcb+0x25d/0x2c0
RSP: 0018:ffffa371c00a3e60 EFLAGS: 00010082
CR2: ffffffff9911c8c8 CR3: 000000040fa20005 CR4: 00000000001706f0
Call Trace:
<TASK>
? __die+0x23/0x80
? page_fault_oops+0xa4/0x180
? exc_page_fault+0x152/0x180
? asm_exc_page_fault+0x26/0x40
? rcu_tasks_need_gpcb+0x25d/0x2c0
? __pfx_rcu_tasks_kthread+0x40/0x40
rcu_tasks_one_gp+0x69/0x180
rcu_tasks_kthread+0x94/0xc0
kthread+0xe8/0x140
? __pfx_kthread+0x40/0x40
ret_from_fork+0x34/0x80
? __pfx_kthread+0x40/0x40
ret_from_fork_asm+0x1b/0x80
</TASK>
Considering that there may be holes in the CPU numbers, use the
maximum possible cpu number, instead of nr_cpu_ids, for configuring
enqueue and dequeue limits.
[ neeraj.upadhyay: Fix htmldocs build error reported by Stephen Rothwell ]
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
x86/ioapic: Handle allocation failures gracefully
Breno observed panics when using failslab under certain conditions during
runtime:
can not alloc irq_pin_list (-1,0,20)
Kernel panic - not syncing: IO-APIC: failed to add irq-pin. Can not proceed
panic+0x4e9/0x590
mp_irqdomain_alloc+0x9ab/0xa80
irq_domain_alloc_irqs_locked+0x25d/0x8d0
__irq_domain_alloc_irqs+0x80/0x110
mp_map_pin_to_irq+0x645/0x890
acpi_register_gsi_ioapic+0xe6/0x150
hpet_open+0x313/0x480
That's a pointless panic which is a leftover of the historic IO/APIC code
which panic'ed during early boot when the interrupt allocation failed.
The only place which might justify panic is the PIT/HPET timer_check() code
which tries to figure out whether the timer interrupt is delivered through
the IO/APIC. But that code does not require to handle interrupt allocation
failures. If the interrupt cannot be allocated then timer delivery fails
and it either panics due to that or falls back to legacy mode.
Cure this by removing the panic wrapper around __add_pin_to_irq_node() and
making mp_irqdomain_alloc() aware of the failure condition and handle it as
any other failure in this function gracefully.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-10-21