| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: Remove calls to drm_put_dev()
Since the allocation of the drivers main structure was changed to
devm_drm_dev_alloc() drm_put_dev()'ing to trigger it to be free'd
should be done by devres.
However, drm_put_dev() is still in the probe error and device remove
paths. When the driver fails to probe warnings like the following are
shown because devres is trying to drm_put_dev() after the driver
already did it.
[ 5.642230] radeon 0000:01:05.0: probe with driver radeon failed with error -22
[ 5.649605] ------------[ cut here ]------------
[ 5.649607] refcount_t: underflow; use-after-free.
[ 5.649620] WARNING: CPU: 0 PID: 357 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
(cherry picked from commit 3eb8c0b4c091da0a623ade0d3ee7aa4a93df1ea4) |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: hda/hdmi: Fix breakage at probing nvhdmi-mcp driver
After restructuring and splitting the HDMI codec driver code, each
HDMI codec driver contains the own build_controls and build_pcms ops.
A copy-n-paste error put the wrong entries for nvhdmi-mcp driver; both
build_controls and build_pcms are swapped. Unfortunately both
callbacks have the very same form, and the compiler didn't complain
it, either. This resulted in a NULL dereference because the PCM
instance hasn't been initialized at calling the build_controls
callback.
Fix it by passing the proper entries. |
| In the Linux kernel, the following vulnerability has been resolved:
sysfs: check visibility before changing group attribute ownership
Since commit 0c17270f9b92 ("net: sysfs: Implement is_visible for
phys_(port_id, port_name, switch_id)"), __dev_change_net_namespace() can
hit WARN_ON() when trying to change owner of a file that isn't visible.
See the trace below:
WARNING: CPU: 6 PID: 2938 at net/core/dev.c:12410 __dev_change_net_namespace+0xb89/0xc30
CPU: 6 UID: 0 PID: 2938 Comm: incusd Not tainted 6.17.1-1-mainline #1 PREEMPT(full) 4b783b4a638669fb644857f484487d17cb45ed1f
Hardware name: Framework Laptop 13 (AMD Ryzen 7040Series)/FRANMDCP07, BIOS 03.07 02/19/2025
RIP: 0010:__dev_change_net_namespace+0xb89/0xc30
[...]
Call Trace:
<TASK>
? if6_seq_show+0x30/0x50
do_setlink.isra.0+0xc7/0x1270
? __nla_validate_parse+0x5c/0xcc0
? security_capable+0x94/0x1a0
rtnl_newlink+0x858/0xc20
? update_curr+0x8e/0x1c0
? update_entity_lag+0x71/0x80
? sched_balance_newidle+0x358/0x450
? psi_task_switch+0x113/0x2a0
? __pfx_rtnl_newlink+0x10/0x10
rtnetlink_rcv_msg+0x346/0x3e0
? sched_clock+0x10/0x30
? __pfx_rtnetlink_rcv_msg+0x10/0x10
netlink_rcv_skb+0x59/0x110
netlink_unicast+0x285/0x3c0
? __alloc_skb+0xdb/0x1a0
netlink_sendmsg+0x20d/0x430
____sys_sendmsg+0x39f/0x3d0
? import_iovec+0x2f/0x40
___sys_sendmsg+0x99/0xe0
__sys_sendmsg+0x8a/0xf0
do_syscall_64+0x81/0x970
? __sys_bind+0xe3/0x110
? syscall_exit_work+0x143/0x1b0
? do_syscall_64+0x244/0x970
? sock_alloc_file+0x63/0xc0
? syscall_exit_work+0x143/0x1b0
? do_syscall_64+0x244/0x970
? alloc_fd+0x12e/0x190
? put_unused_fd+0x2a/0x70
? do_sys_openat2+0xa2/0xe0
? syscall_exit_work+0x143/0x1b0
? do_syscall_64+0x244/0x970
? exc_page_fault+0x7e/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[...]
</TASK>
Fix this by checking is_visible() before trying to touch the attribute. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: fix potential use after free in iwl_mld_remove_link()
This code frees "link" by calling kfree_rcu(link, rcu_head) and then it
dereferences "link" to get the "link->fw_id". Save the "link->fw_id"
first to avoid a potential use after free. |
| In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Fix unsafe locking in the scx_dump_state()
For built with CONFIG_PREEMPT_RT=y kernels, the dump_lock will be converted
sleepable spinlock and not disable-irq, so the following scenarios occur:
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
irq_work/0/27 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&rq->__lock){?...}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x40
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0x1e1/0x510
_raw_spin_lock_nested+0x42/0x80
raw_spin_rq_lock_nested+0x2b/0x40
sched_tick+0xae/0x7b0
update_process_times+0x14c/0x1b0
tick_periodic+0x62/0x1f0
tick_handle_periodic+0x48/0xf0
timer_interrupt+0x55/0x80
__handle_irq_event_percpu+0x20a/0x5c0
handle_irq_event_percpu+0x18/0xc0
handle_irq_event+0xb5/0x150
handle_level_irq+0x220/0x460
__common_interrupt+0xa2/0x1e0
common_interrupt+0xb0/0xd0
asm_common_interrupt+0x2b/0x40
_raw_spin_unlock_irqrestore+0x45/0x80
__setup_irq+0xc34/0x1a30
request_threaded_irq+0x214/0x2f0
hpet_time_init+0x3e/0x60
x86_late_time_init+0x5b/0xb0
start_kernel+0x308/0x410
x86_64_start_reservations+0x1c/0x30
x86_64_start_kernel+0x96/0xa0
common_startup_64+0x13e/0x148
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&rq->__lock);
<Interrupt>
lock(&rq->__lock);
*** DEADLOCK ***
stack backtrace:
CPU: 0 UID: 0 PID: 27 Comm: irq_work/0
Call Trace:
<TASK>
dump_stack_lvl+0x8c/0xd0
dump_stack+0x14/0x20
print_usage_bug+0x42e/0x690
mark_lock.part.44+0x867/0xa70
? __pfx_mark_lock.part.44+0x10/0x10
? string_nocheck+0x19c/0x310
? number+0x739/0x9f0
? __pfx_string_nocheck+0x10/0x10
? __pfx_check_pointer+0x10/0x10
? kvm_sched_clock_read+0x15/0x30
? sched_clock_noinstr+0xd/0x20
? local_clock_noinstr+0x1c/0xe0
__lock_acquire+0xc4b/0x62b0
? __pfx_format_decode+0x10/0x10
? __pfx_string+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
? __pfx_vsnprintf+0x10/0x10
lock_acquire+0x1e1/0x510
? raw_spin_rq_lock_nested+0x2b/0x40
? __pfx_lock_acquire+0x10/0x10
? dump_line+0x12e/0x270
? raw_spin_rq_lock_nested+0x20/0x40
_raw_spin_lock_nested+0x42/0x80
? raw_spin_rq_lock_nested+0x2b/0x40
raw_spin_rq_lock_nested+0x2b/0x40
scx_dump_state+0x3b3/0x1270
? finish_task_switch+0x27e/0x840
scx_ops_error_irq_workfn+0x67/0x80
irq_work_single+0x113/0x260
irq_work_run_list.part.3+0x44/0x70
run_irq_workd+0x6b/0x90
? __pfx_run_irq_workd+0x10/0x10
smpboot_thread_fn+0x529/0x870
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x305/0x3f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x40/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This commit therefore use rq_lock_irqsave/irqrestore() to replace
rq_lock/unlock() in the scx_dump_state(). |
| In the Linux kernel, the following vulnerability has been resolved:
slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts
If two competing threads enter alloc_slab_obj_exts() and one of them
fails to allocate the object extension vector, it might override the
valid slab->obj_exts allocated by the other thread with
OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and
expects a valid pointer to dereference a NULL pointer later on.
Update slab->obj_exts atomically using cmpxchg() to avoid
slab->obj_exts overrides by racing threads.
Thanks for Vlastimil and Suren's help with debugging. |
| In the Linux kernel, the following vulnerability has been resolved:
codetag: debug: handle existing CODETAG_EMPTY in mark_objexts_empty for slabobj_ext
When alloc_slab_obj_exts() fails and then later succeeds in allocating a
slab extension vector, it calls handle_failed_objexts_alloc() to mark all
objects in the vector as empty. As a result all objects in this slab
(slabA) will have their extensions set to CODETAG_EMPTY.
Later on if this slabA is used to allocate a slabobj_ext vector for
another slab (slabB), we end up with the slabB->obj_exts pointing to a
slabobj_ext vector that itself has a non-NULL slabobj_ext equal to
CODETAG_EMPTY. When slabB gets freed, free_slab_obj_exts() is called to
free slabB->obj_exts vector.
free_slab_obj_exts() calls mark_objexts_empty(slabB->obj_exts) which will
generate a warning because it expects slabobj_ext vectors to have a NULL
obj_ext, not CODETAG_EMPTY.
Modify mark_objexts_empty() to skip the warning and setting the obj_ext
value if it's already set to CODETAG_EMPTY.
To quickly detect this WARN, I modified the code from
WARN_ON(slab_exts[offs].ref.ct) to BUG_ON(slab_exts[offs].ref.ct == 1);
We then obtained this message:
[21630.898561] ------------[ cut here ]------------
[21630.898596] kernel BUG at mm/slub.c:2050!
[21630.898611] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
[21630.900372] Modules linked in: squashfs isofs vfio_iommu_type1
vhost_vsock vfio vhost_net vmw_vsock_virtio_transport_common vhost tap
vhost_iotlb iommufd vsock binfmt_misc nfsv3 nfs_acl nfs lockd grace
netfs tls rds dns_resolver tun brd overlay ntfs3 exfat btrfs
blake2b_generic xor xor_neon raid6_pq loop sctp ip6_udp_tunnel
udp_tunnel nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib
nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct
nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4
nf_tables rfkill ip_set sunrpc vfat fat joydev sg sch_fq_codel nfnetlink
virtio_gpu sr_mod cdrom drm_client_lib virtio_dma_buf drm_shmem_helper
drm_kms_helper drm ghash_ce backlight virtio_net virtio_blk virtio_scsi
net_failover virtio_console failover virtio_mmio dm_mirror
dm_region_hash dm_log dm_multipath dm_mod fuse i2c_dev virtio_pci
virtio_pci_legacy_dev virtio_pci_modern_dev virtio virtio_ring autofs4
aes_neon_bs aes_ce_blk [last unloaded: hwpoison_inject]
[21630.909177] CPU: 3 UID: 0 PID: 3787 Comm: kylin-process-m Kdump:
loaded Tainted: G W 6.18.0-rc1+ #74 PREEMPT(voluntary)
[21630.910495] Tainted: [W]=WARN
[21630.910867] Hardware name: QEMU KVM Virtual Machine, BIOS unknown
2/2/2022
[21630.911625] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[21630.912392] pc : __free_slab+0x228/0x250
[21630.912868] lr : __free_slab+0x18c/0x250[21630.913334] sp :
ffff8000a02f73e0
[21630.913830] x29: ffff8000a02f73e0 x28: fffffdffc43fc800 x27:
ffff0000c0011c40
[21630.914677] x26: ffff0000c000cac0 x25: ffff00010fe5e5f0 x24:
ffff000102199b40
[21630.915469] x23: 0000000000000003 x22: 0000000000000003 x21:
ffff0000c0011c40
[21630.916259] x20: fffffdffc4086600 x19: fffffdffc43fc800 x18:
0000000000000000
[21630.917048] x17: 0000000000000000 x16: 0000000000000000 x15:
0000000000000000
[21630.917837] x14: 0000000000000000 x13: 0000000000000000 x12:
ffff70001405ee66
[21630.918640] x11: 1ffff0001405ee65 x10: ffff70001405ee65 x9 :
ffff800080a295dc
[21630.919442] x8 : ffff8000a02f7330 x7 : 0000000000000000 x6 :
0000000000003000
[21630.920232] x5 : 0000000024924925 x4 : 0000000000000001 x3 :
0000000000000007
[21630.921021] x2 : 0000000000001b40 x1 : 000000000000001f x0 :
0000000000000001
[21630.921810] Call trace:
[21630.922130] __free_slab+0x228/0x250 (P)
[21630.922669] free_slab+0x38/0x118
[21630.923079] free_to_partial_list+0x1d4/0x340
[21630.923591] __slab_free+0x24c/0x348
[21630.924024] ___cache_free+0xf0/0x110
[21630.924468] qlist_free_all+0x78/0x130
[21630.924922] kasan_quarantine_reduce+0x11
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix null pointer dereference in bnxt_bs_trace_check_wrap()
With older FW, we may get the ASYNC_EVENT_CMPL_EVENT_ID_DBG_BUF_PRODUCER
for FW trace data type that has not been initialized. This will result
in a crash in bnxt_bs_trace_type_wrap(). Add a guard to check for a
valid magic_byte pointer before proceeding. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/guc: Synchronize Dead CT worker with unbind
Cancel and wait for any Dead CT worker to complete before continuing
with device unbinding. Else the worker will end up using resources freed
by the undind operation.
(cherry picked from commit 492671339114e376aaa38626d637a2751cdef263) |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: RX, Fix generating skb from non-linear xdp_buff for striding RQ
XDP programs can change the layout of an xdp_buff through
bpf_xdp_adjust_tail() and bpf_xdp_adjust_head(). Therefore, the driver
cannot assume the size of the linear data area nor fragments. Fix the
bug in mlx5 by generating skb according to xdp_buff after XDP programs
run.
Currently, when handling multi-buf XDP, the mlx5 driver assumes the
layout of an xdp_buff to be unchanged. That is, the linear data area
continues to be empty and fragments remain the same. This may cause
the driver to generate erroneous skb or triggering a kernel
warning. When an XDP program added linear data through
bpf_xdp_adjust_head(), the linear data will be ignored as
mlx5e_build_linear_skb() builds an skb without linear data and then
pull data from fragments to fill the linear data area. When an XDP
program has shrunk the non-linear data through bpf_xdp_adjust_tail(),
the delta passed to __pskb_pull_tail() may exceed the actual nonlinear
data size and trigger the BUG_ON in it.
To fix the issue, first record the original number of fragments. If the
number of fragments changes after the XDP program runs, rewind the end
fragment pointer by the difference and recalculate the truesize. Then,
build the skb with the linear data area matching the xdp_buff. Finally,
only pull data in if there is non-linear data and fill the linear part
up to 256 bytes. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Add bpf_prog_run_data_pointers()
syzbot found that cls_bpf_classify() is able to change
tc_skb_cb(skb)->drop_reason triggering a warning in sk_skb_reason_drop().
WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 __sk_skb_reason_drop net/core/skbuff.c:1189 [inline]
WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 sk_skb_reason_drop+0x76/0x170 net/core/skbuff.c:1214
struct tc_skb_cb has been added in commit ec624fe740b4 ("net/sched:
Extend qdisc control block with tc control block"), which added a wrong
interaction with db58ba459202 ("bpf: wire in data and data_end for
cls_act_bpf").
drop_reason was added later.
Add bpf_prog_run_data_pointers() helper to save/restore the net_sched
storage colliding with BPF data_meta/data_end. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/fpu: Ensure XFD state on signal delivery
Sean reported [1] the following splat when running KVM tests:
WARNING: CPU: 232 PID: 15391 at xfd_validate_state+0x65/0x70
Call Trace:
<TASK>
fpu__clear_user_states+0x9c/0x100
arch_do_signal_or_restart+0x142/0x210
exit_to_user_mode_loop+0x55/0x100
do_syscall_64+0x205/0x2c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Chao further identified [2] a reproducible scenario involving signal
delivery: a non-AMX task is preempted by an AMX-enabled task which
modifies the XFD MSR.
When the non-AMX task resumes and reloads XSTATE with init values,
a warning is triggered due to a mismatch between fpstate::xfd and the
CPU's current XFD state. fpu__clear_user_states() does not currently
re-synchronize the XFD state after such preemption.
Invoke xfd_update_state() which detects and corrects the mismatch if
there is a dynamic feature.
This also benefits the sigreturn path, as fpu__restore_sig() may call
fpu__clear_user_states() when the sigframe is inaccessible.
[ dhansen: minor changelog munging ] |
| In the Linux kernel, the following vulnerability has been resolved:
net: enetc: fix the deadlock of enetc_mdio_lock
After applying the workaround for err050089, the LS1028A platform
experiences RCU stalls on RT kernel. This issue is caused by the
recursive acquisition of the read lock enetc_mdio_lock. Here list some
of the call stacks identified under the enetc_poll path that may lead to
a deadlock:
enetc_poll
-> enetc_lock_mdio
-> enetc_clean_rx_ring OR napi_complete_done
-> napi_gro_receive
-> enetc_start_xmit
-> enetc_lock_mdio
-> enetc_map_tx_buffs
-> enetc_unlock_mdio
-> enetc_unlock_mdio
After enetc_poll acquires the read lock, a higher-priority writer attempts
to acquire the lock, causing preemption. The writer detects that a
read lock is already held and is scheduled out. However, readers under
enetc_poll cannot acquire the read lock again because a writer is already
waiting, leading to a thread hang.
Currently, the deadlock is avoided by adjusting enetc_lock_mdio to prevent
recursive lock acquisition. |
| In the Linux kernel, the following vulnerability has been resolved:
s390: Disable ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
As reported by Luiz Capitulino enabling HVO on s390 leads to reproducible
crashes. The problem is that kernel page tables are modified without
flushing corresponding TLB entries.
Even if it looks like the empty flush_tlb_all() implementation on s390 is
the problem, it is actually a different problem: on s390 it is not allowed
to replace an active/valid page table entry with another valid page table
entry without the detour over an invalid entry. A direct replacement may
lead to random crashes and/or data corruption.
In order to invalidate an entry special instructions have to be used
(e.g. ipte or idte). Alternatively there are also special instructions
available which allow to replace a valid entry with a different valid
entry (e.g. crdte or cspg).
Given that the HVO code currently does not provide the hooks to allow for
an implementation which is compliant with the s390 architecture
requirements, disable ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP again, which is
basically a revert of the original patch which enabled it. |
| In the Linux kernel, the following vulnerability has been resolved:
net: usb: qmi_wwan: initialize MAC header offset in qmimux_rx_fixup
Raw IP packets have no MAC header, leaving skb->mac_header uninitialized.
This can trigger kernel panics on ARM64 when xfrm or other subsystems
access the offset due to strict alignment checks.
Initialize the MAC header to prevent such crashes.
This can trigger kernel panics on ARM when running IPsec over the
qmimux0 interface.
Example trace:
Internal error: Oops: 000000009600004f [#1] SMP
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.34-gbe78e49cb433 #1
Hardware name: LS1028A RDB Board (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : xfrm_input+0xde8/0x1318
lr : xfrm_input+0x61c/0x1318
sp : ffff800080003b20
Call trace:
xfrm_input+0xde8/0x1318
xfrm6_rcv+0x38/0x44
xfrm6_esp_rcv+0x48/0xa8
ip6_protocol_deliver_rcu+0x94/0x4b0
ip6_input_finish+0x44/0x70
ip6_input+0x44/0xc0
ipv6_rcv+0x6c/0x114
__netif_receive_skb_one_core+0x5c/0x8c
__netif_receive_skb+0x18/0x60
process_backlog+0x78/0x17c
__napi_poll+0x38/0x180
net_rx_action+0x168/0x2f0 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: Disable AFBC support on Mediatek DRM driver
Commit c410fa9b07c3 ("drm/mediatek: Add AFBC support to Mediatek DRM
driver") added AFBC support to Mediatek DRM and enabled the
32x8/split/sparse modifier.
However, this is currently broken on Mediatek MT8188 (Genio 700 EVK
platform); tested using upstream Kernel and Mesa (v25.2.1), AFBC is used by
default since Mesa v25.0.
Kernel trace reports vblank timeouts constantly, and the render is garbled:
```
[CRTC:62:crtc-0] vblank wait timed out
WARNING: CPU: 7 PID: 70 at drivers/gpu/drm/drm_atomic_helper.c:1835 drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c
[...]
Hardware name: MediaTek Genio-700 EVK (DT)
Workqueue: events_unbound commit_work
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c
lr : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c
sp : ffff80008337bca0
x29: ffff80008337bcd0 x28: 0000000000000061 x27: 0000000000000000
x26: 0000000000000001 x25: 0000000000000000 x24: ffff0000c9dcc000
x23: 0000000000000001 x22: 0000000000000000 x21: ffff0000c66f2f80
x20: ffff0000c0d7d880 x19: 0000000000000000 x18: 000000000000000a
x17: 000000040044ffff x16: 005000f2b5503510 x15: 0000000000000000
x14: 0000000000000000 x13: 74756f2064656d69 x12: 742074696177206b
x11: 0000000000000058 x10: 0000000000000018 x9 : ffff800082396a70
x8 : 0000000000057fa8 x7 : 0000000000000cce x6 : ffff8000823eea70
x5 : ffff0001fef5f408 x4 : ffff80017ccee000 x3 : ffff0000c12cb480
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c12cb480
Call trace:
drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c (P)
drm_atomic_helper_commit_tail_rpm+0x64/0x80
commit_tail+0xa4/0x1a4
commit_work+0x14/0x20
process_one_work+0x150/0x290
worker_thread+0x2d0/0x3ec
kthread+0x12c/0x210
ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
```
Until this gets fixed upstream, disable AFBC support on this platform, as
it's currently broken with upstream Mesa. |
| In the Linux kernel, the following vulnerability has been resolved:
crash: fix crashkernel resource shrink
When crashkernel is configured with a high reservation, shrinking its
value below the low crashkernel reservation causes two issues:
1. Invalid crashkernel resource objects
2. Kernel crash if crashkernel shrinking is done twice
For example, with crashkernel=200M,high, the kernel reserves 200MB of high
memory and some default low memory (say 256MB). The reservation appears
as:
cat /proc/iomem | grep -i crash
af000000-beffffff : Crash kernel
433000000-43f7fffff : Crash kernel
If crashkernel is then shrunk to 50MB (echo 52428800 >
/sys/kernel/kexec_crash_size), /proc/iomem still shows 256MB reserved:
af000000-beffffff : Crash kernel
Instead, it should show 50MB:
af000000-b21fffff : Crash kernel
Further shrinking crashkernel to 40MB causes a kernel crash with the
following trace (x86):
BUG: kernel NULL pointer dereference, address: 0000000000000038
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
<snip...>
Call Trace: <TASK>
? __die_body.cold+0x19/0x27
? page_fault_oops+0x15a/0x2f0
? search_module_extables+0x19/0x60
? search_bpf_extables+0x5f/0x80
? exc_page_fault+0x7e/0x180
? asm_exc_page_fault+0x26/0x30
? __release_resource+0xd/0xb0
release_resource+0x26/0x40
__crash_shrink_memory+0xe5/0x110
crash_shrink_memory+0x12a/0x190
kexec_crash_size_store+0x41/0x80
kernfs_fop_write_iter+0x141/0x1f0
vfs_write+0x294/0x460
ksys_write+0x6d/0xf0
<snip...>
This happens because __crash_shrink_memory()/kernel/crash_core.c
incorrectly updates the crashk_res resource object even when
crashk_low_res should be updated.
Fix this by ensuring the correct crashkernel resource object is updated
when shrinking crashkernel memory. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: account for current allocated stack depth in widen_imprecise_scalars()
The usage pattern for widen_imprecise_scalars() looks as follows:
prev_st = find_prev_entry(env, ...);
queued_st = push_stack(...);
widen_imprecise_scalars(env, prev_st, queued_st);
Where prev_st is an ancestor of the queued_st in the explored states
tree. This ancestor is not guaranteed to have same allocated stack
depth as queued_st. E.g. in the following case:
def main():
for i in 1..2:
foo(i) // same callsite, differnt param
def foo(i):
if i == 1:
use 128 bytes of stack
iterator based loop
Here, for a second 'foo' call prev_st->allocated_stack is 128,
while queued_st->allocated_stack is much smaller.
widen_imprecise_scalars() needs to take this into account and avoid
accessing bpf_verifier_state->frame[*]->stack out of bounds. |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: Check the TLS certificate fields in nfs_match_client()
If the TLS security policy is of type RPC_XPRTSEC_TLS_X509, then the
cert_serial and privkey_serial fields need to match as well since they
define the client's identity, as presented to the server. |
| In the Linux kernel, the following vulnerability has been resolved:
netconsole: Acquire su_mutex before navigating configs hierarchy
There is a race between operations that iterate over the userdata
cg_children list and concurrent add/remove of userdata items through
configfs. The update_userdata() function iterates over the
nt->userdata_group.cg_children list, and count_extradata_entries() also
iterates over this same list to count nodes.
Quoting from Documentation/filesystems/configfs.rst:
> A subsystem can navigate the cg_children list and the ci_parent pointer
> to see the tree created by the subsystem. This can race with configfs'
> management of the hierarchy, so configfs uses the subsystem mutex to
> protect modifications. Whenever a subsystem wants to navigate the
> hierarchy, it must do so under the protection of the subsystem
> mutex.
Without proper locking, if a userdata item is added or removed
concurrently while these functions are iterating, the list can be
accessed in an inconsistent state. For example, the list_for_each() loop
can reach a node that is being removed from the list by list_del_init()
which sets the nodes' .next pointer to point to itself, so the loop will
never end (or reach the WARN_ON_ONCE in update_userdata() ).
Fix this by holding the configfs subsystem mutex (su_mutex) during all
operations that iterate over cg_children.
This includes:
- userdatum_value_store() which calls update_userdata() to iterate over
cg_children
- All sysdata_*_enabled_store() functions which call
count_extradata_entries() to iterate over cg_children
The su_mutex must be acquired before dynamic_netconsole_mutex to avoid
potential lock ordering issues, as configfs operations may already hold
su_mutex when calling into our code. |
