Linux: >> Linux Kernel >> 6.6.49 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: libwx: fix the using of Rx buffer DMA
The wx_rx_buffer structure contained two DMA address fields: 'dma' and
'page_dma'. However, only 'page_dma' was actually initialized and used
to program the Rx descriptor. But 'dma' was uninitialized and used in
some paths.
This could lead to undefined behavior, including DMA errors or
use-after-free, if the uninitialized 'dma' was used. Althrough such
error has not yet occurred, it is worth fixing in the code.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-16
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix recv-recv race of completed call
If a call receives an event (such as incoming data), the call gets placed
on the socket's queue and a thread in recvmsg can be awakened to go and
process it. Once the thread has picked up the call off of the queue,
further events will cause it to be requeued, and once the socket lock is
dropped (recvmsg uses call->user_mutex to allow the socket to be used in
parallel), a second thread can come in and its recvmsg can pop the call off
the socket queue again.
In such a case, the first thread will be receiving stuff from the call and
the second thread will be blocked on call->user_mutex. The first thread
can, at this point, process both the event that it picked call for and the
event that the second thread picked the call for and may see the call
terminate - in which case the call will be "released", decoupling the call
from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control
message).
The first thread will return okay, but then the second thread will wake up
holding the user_mutex and, if it sees that the call has been released by
the first thread, it will BUG thusly:
kernel BUG at net/rxrpc/recvmsg.c:474!
Fix this by just dequeuing the call and ignoring it if it is seen to be
already released. We can't tell userspace about it anyway as the user call
ID has become stale.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-08-16
In the Linux kernel, the following vulnerability has been resolved:
HID: nintendo: avoid bluetooth suspend/resume stalls
Ensure we don't stall or panic the kernel when using bluetooth-connected
controllers. This was reported as an issue on android devices using
kernel 6.6 due to the resume hook which had been added for usb joycons.
First, set a new state value to JOYCON_CTLR_STATE_SUSPENDED in a
newly-added nintendo_hid_suspend. This makes sure we will not stall out
the kernel waiting for input reports during led classdev suspend. The
stalls could happen if connectivity is unreliable or lost to the
controller prior to suspend.
Second, since we lose connectivity during suspend, do not try
joycon_init() for bluetooth controllers in the nintendo_hid_resume path.
Tested via multiple suspend/resume flows when using the controller both
in USB and bluetooth modes.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-16
In the Linux kernel, the following vulnerability has been resolved:
net: libwx: remove duplicate page_pool_put_full_page()
page_pool_put_full_page() should only be invoked when freeing Rx buffers
or building a skb if the size is too short. At other times, the pages
need to be reused. So remove the redundant page put. In the original
code, double free pages cause kernel panic:
[ 876.949834] __irq_exit_rcu+0xc7/0x130
[ 876.949836] common_interrupt+0xb8/0xd0
[ 876.949838] </IRQ>
[ 876.949838] <TASK>
[ 876.949840] asm_common_interrupt+0x22/0x40
[ 876.949841] RIP: 0010:cpuidle_enter_state+0xc2/0x420
[ 876.949843] Code: 00 00 e8 d1 1d 5e ff e8 ac f0 ff ff 49 89 c5 0f 1f 44 00 00 31 ff e8 cd fc 5c ff 45 84 ff 0f 85 40 02 00 00 fb 0f 1f 44 00 00 <45> 85 f6 0f 88 84 01 00 00 49 63 d6 48 8d 04 52 48 8d 04 82 49 8d
[ 876.949844] RSP: 0018:ffffaa7340267e78 EFLAGS: 00000246
[ 876.949845] RAX: ffff9e3f135be000 RBX: 0000000000000002 RCX: 0000000000000000
[ 876.949846] RDX: 000000cc2dc4cb7c RSI: ffffffff89ee49ae RDI: ffffffff89ef9f9e
[ 876.949847] RBP: ffff9e378f940800 R08: 0000000000000002 R09: 00000000000000ed
[ 876.949848] R10: 000000000000afc8 R11: ffff9e3e9e5a9b6c R12: ffffffff8a6d8580
[ 876.949849] R13: 000000cc2dc4cb7c R14: 0000000000000002 R15: 0000000000000000
[ 876.949852] ? cpuidle_enter_state+0xb3/0x420
[ 876.949855] cpuidle_enter+0x29/0x40
[ 876.949857] cpuidle_idle_call+0xfd/0x170
[ 876.949859] do_idle+0x7a/0xc0
[ 876.949861] cpu_startup_entry+0x25/0x30
[ 876.949862] start_secondary+0x117/0x140
[ 876.949864] common_startup_64+0x13e/0x148
[ 876.949867] </TASK>
[ 876.949868] ---[ end trace 0000000000000000 ]---
[ 876.949869] ------------[ cut here ]------------
[ 876.949870] list_del corruption, ffffead40445a348->next is NULL
[ 876.949873] WARNING: CPU: 14 PID: 0 at lib/list_debug.c:52 __list_del_entry_valid_or_report+0x67/0x120
[ 876.949875] Modules linked in: snd_hrtimer(E) bnep(E) binfmt_misc(E) amdgpu(E) squashfs(E) vfat(E) loop(E) fat(E) amd_atl(E) snd_hda_codec_realtek(E) intel_rapl_msr(E) snd_hda_codec_generic(E) intel_rapl_common(E) snd_hda_scodec_component(E) snd_hda_codec_hdmi(E) snd_hda_intel(E) edac_mce_amd(E) snd_intel_dspcfg(E) snd_hda_codec(E) snd_hda_core(E) amdxcp(E) kvm_amd(E) snd_hwdep(E) gpu_sched(E) drm_panel_backlight_quirks(E) cec(E) snd_pcm(E) drm_buddy(E) snd_seq_dummy(E) drm_ttm_helper(E) btusb(E) kvm(E) snd_seq_oss(E) btrtl(E) ttm(E) btintel(E) snd_seq_midi(E) btbcm(E) drm_exec(E) snd_seq_midi_event(E) i2c_algo_bit(E) snd_rawmidi(E) bluetooth(E) drm_suballoc_helper(E) irqbypass(E) snd_seq(E) ghash_clmulni_intel(E) sha512_ssse3(E) drm_display_helper(E) aesni_intel(E) snd_seq_device(E) rfkill(E) snd_timer(E) gf128mul(E) drm_client_lib(E) drm_kms_helper(E) snd(E) i2c_piix4(E) joydev(E) soundcore(E) wmi_bmof(E) ccp(E) k10temp(E) i2c_smbus(E) gpio_amdpt(E) i2c_designware_platform(E) gpio_generic(E) sg(E)
[ 876.949914] i2c_designware_core(E) sch_fq_codel(E) parport_pc(E) drm(E) ppdev(E) lp(E) parport(E) fuse(E) nfnetlink(E) ip_tables(E) ext4 crc16 mbcache jbd2 sd_mod sfp mdio_i2c i2c_core txgbe ahci ngbe pcs_xpcs libahci libwx r8169 phylink libata realtek ptp pps_core video wmi
[ 876.949933] CPU: 14 UID: 0 PID: 0 Comm: swapper/14 Kdump: loaded Tainted: G W E 6.16.0-rc2+ #20 PREEMPT(voluntary)
[ 876.949935] Tainted: [W]=WARN, [E]=UNSIGNED_MODULE
[ 876.949936] Hardware name: Micro-Star International Co., Ltd. MS-7E16/X670E GAMING PLUS WIFI (MS-7E16), BIOS 1.90 12/31/2024
[ 876.949936] RIP: 0010:__list_del_entry_valid_or_report+0x67/0x120
[ 876.949938] Code: 00 00 00 48 39 7d 08 0f 85 a6 00 00 00 5b b8 01 00 00 00 5d 41 5c e9 73 0d 93 ff 48 89 fe 48 c7 c7 a0 31 e8 89 e8 59 7c b3 ff <0f> 0b 31 c0 5b 5d 41 5c e9 57 0d 93 ff 48 89 fe 48 c7 c7 c8 31 e8
[ 876.949940] RSP: 0018:ffffaa73405d0c60 EFLAGS: 00010282
[ 876.949941] RAX: 0000000000000000 RBX: ffffead40445a348 RCX: 0000000000000000
[ 876.949942] RDX: 0000000000000105 RSI: 00000
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
tracing/osnoise: Fix crash in timerlat_dump_stack()
We have observed kernel panics when using timerlat with stack saving,
with the following dmesg output:
memcpy: detected buffer overflow: 88 byte write of buffer size 0
WARNING: CPU: 2 PID: 8153 at lib/string_helpers.c:1032 __fortify_report+0x55/0xa0
CPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy)
Call Trace:
<TASK>
? trace_buffer_lock_reserve+0x2a/0x60
__fortify_panic+0xd/0xf
__timerlat_dump_stack.cold+0xd/0xd
timerlat_dump_stack.part.0+0x47/0x80
timerlat_fd_read+0x36d/0x390
vfs_read+0xe2/0x390
? syscall_exit_to_user_mode+0x1d5/0x210
ksys_read+0x73/0xe0
do_syscall_64+0x7b/0x160
? exc_page_fault+0x7e/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
__timerlat_dump_stack() constructs the ftrace stack entry like this:
struct stack_entry *entry;
...
memcpy(&entry->caller, fstack->calls, size);
entry->size = fstack->nr_entries;
Since commit e7186af7fb26 ("tracing: Add back FORTIFY_SOURCE logic to
kernel_stack event structure"), struct stack_entry marks its caller
field with __counted_by(size). At the time of the memcpy, entry->size
contains garbage from the ringbuffer, which under some circumstances is
zero, triggering a kernel panic by buffer overflow.
Populate the size field before the memcpy so that the out-of-bounds
check knows the correct size. This is analogous to
__ftrace_trace_stack().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
dm-bufio: fix sched in atomic context
If "try_verify_in_tasklet" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP
is enabled for dm-bufio. However, when bufio tries to evict buffers, there
is a chance to trigger scheduling in spin_lock_bh, the following warning
is hit:
BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2
preempt_count: 201, expected: 0
RCU nest depth: 0, expected: 0
4 locks held by kworker/2:2/123:
#0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970
#1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970
#2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710
#3: ffff88801d5820b8 (&c->spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: dm_bufio_cache do_global_cleanup
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
__might_resched+0x360/0x4e0
do_global_cleanup+0x2f5/0x710
process_one_work+0x7db/0x1970
worker_thread+0x518/0xea0
kthread+0x359/0x690
ret_from_fork+0xf3/0x1b0
ret_from_fork_asm+0x1a/0x30
</TASK>
That can be reproduced by:
veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb
SIZE=$(blockdev --getsz /dev/vda)
dmsetup create myverity -r --table "0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 <data_blocks> 1 sha256 <root_hash> <salt> 1 try_verify_in_tasklet"
mount /dev/dm-0 /mnt -o ro
echo 102400 > /sys/module/dm_bufio/parameters/max_cache_size_bytes
[read files in /mnt]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
s390/bpf: Fix bpf_arch_text_poke() with new_addr == NULL again
Commit 7ded842b356d ("s390/bpf: Fix bpf_plt pointer arithmetic") has
accidentally removed the critical piece of commit c730fce7c70c
("s390/bpf: Fix bpf_arch_text_poke() with new_addr == NULL"), causing
intermittent kernel panics in e.g. perf's on_switch() prog to reappear.
Restore the fix and add a comment.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/xen: Fix cleanup logic in emulation of Xen schedop poll hypercalls
kvm_xen_schedop_poll does a kmalloc_array() when a VM polls the host
for more than one event channel potr (nr_ports > 1).
After the kmalloc_array(), the error paths need to go through the
"out" label, but the call to kvm_read_guest_virt() does not.
[Adjusted commit message. - Paolo]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-28
In the Linux kernel, the following vulnerability has been resolved:
tcp: Correct signedness in skb remaining space calculation
Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow.
When we send data, if an skb exists at the tail of the write queue, the
kernel will attempt to append the new data to that skb. However, the code
that checks for available space in the skb is flawed:
'''
copy = size_goal - skb->len
'''
The types of the variables involved are:
'''
copy: ssize_t (s64 on 64-bit systems)
size_goal: int
skb->len: unsigned int
'''
Due to C's type promotion rules, the signed size_goal is converted to an
unsigned int to match skb->len before the subtraction. The result is an
unsigned int.
When this unsigned int result is then assigned to the s64 copy variable,
it is zero-extended, preserving its non-negative value. Consequently, copy
is always >= 0.
Assume we are sending 2GB of data and size_goal has been adjusted to a
value smaller than skb->len. The subtraction will result in copy holding a
very large positive integer. In the subsequent logic, this large value is
used to update sk->sk_forward_alloc, which can easily cause it to overflow.
The syzkaller reproducer uses TCP_REPAIR to reliably create this
condition. However, this can also occur in real-world scenarios. The
tcp_bound_to_half_wnd() function can also reduce size_goal to a small
value. This would cause the subsequent tcp_wmem_schedule() to set
sk->sk_forward_alloc to a value close to INT_MAX. Further memory
allocation requests would then cause sk_forward_alloc to wrap around and
become negative.
[1]: https://syzkaller.appspot.com/bug?extid=de6565462ab540f50e47
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-25
In the Linux kernel, the following vulnerability has been resolved:
drm/gem: Acquire references on GEM handles for framebuffers
A GEM handle can be released while the GEM buffer object is attached
to a DRM framebuffer. This leads to the release of the dma-buf backing
the buffer object, if any. [1] Trying to use the framebuffer in further
mode-setting operations leads to a segmentation fault. Most easily
happens with driver that use shadow planes for vmap-ing the dma-buf
during a page flip. An example is shown below.
[ 156.791968] ------------[ cut here ]------------
[ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430
[...]
[ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430
[ 157.043420] Call Trace:
[ 157.045898] <TASK>
[ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710
[ 157.065567] ? dma_buf_vmap+0x224/0x430
[ 157.069446] ? __warn.cold+0x58/0xe4
[ 157.073061] ? dma_buf_vmap+0x224/0x430
[ 157.077111] ? report_bug+0x1dd/0x390
[ 157.080842] ? handle_bug+0x5e/0xa0
[ 157.084389] ? exc_invalid_op+0x14/0x50
[ 157.088291] ? asm_exc_invalid_op+0x16/0x20
[ 157.092548] ? dma_buf_vmap+0x224/0x430
[ 157.096663] ? dma_resv_get_singleton+0x6d/0x230
[ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10
[ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10
[ 157.110697] drm_gem_shmem_vmap+0x74/0x710
[ 157.114866] drm_gem_vmap+0xa9/0x1b0
[ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0
[ 157.123086] drm_gem_fb_vmap+0xab/0x300
[ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10
[ 157.133032] ? lockdep_init_map_type+0x19d/0x880
[ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0
[ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180
[ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40
[...]
[ 157.346424] ---[ end trace 0000000000000000 ]---
Acquiring GEM handles for the framebuffer's GEM buffer objects prevents
this from happening. The framebuffer's cleanup later puts the handle
references.
Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object
instance") triggers the segmentation fault easily by using the dma-buf
field more widely. The underlying issue with reference counting has
been present before.
v2:
- acquire the handle instead of the BO (Christian)
- fix comment style (Christian)
- drop the Fixes tag (Christian)
- rename err_ gotos
- add missing Link tag
CVSS Score
5.5
EPSS Score
0.0
Published
2025-07-25