Linux: >> Linux Kernel >> 5.4.255 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
btrfs: output extra debug info if we failed to find an inline backref
[BUG]
Syzbot reported several warning triggered inside
lookup_inline_extent_backref().
[CAUSE]
As usual, the reproducer doesn't reliably trigger locally here, but at
least we know the WARN_ON() is triggered when an inline backref can not
be found, and it can only be triggered when @insert is true. (I.e.
inserting a new inline backref, which means the backref should already
exist)
[ENHANCEMENT]
After the WARN_ON(), dump all the parameters and the extent tree
leaf to help debug.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()
The function lio_target_nacl_info_show() uses sprintf() in a loop to print
details for every iSCSI connection in a session without checking for the
buffer length. With enough iSCSI connections it's possible to overflow the
buffer provided by configfs and corrupt the memory.
This patch replaces sprintf() with sysfs_emit_at() that checks for buffer
boundries.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
bnxt: avoid overflow in bnxt_get_nvram_directory()
The value of an arithmetic expression is subject
of possible overflow due to a failure to cast operands to a larger data
type before performing arithmetic. Used macro for multiplication instead
operator for avoiding overflow.
Found by Security Code and Linux Verification
Center (linuxtesting.org) with SVACE.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
Drivers: hv: vmbus: Don't dereference ACPI root object handle
Since the commit referenced in the Fixes: tag below the VMBus client driver
is walking the ACPI namespace up from the VMBus ACPI device to the ACPI
namespace root object trying to find Hyper-V MMIO ranges.
However, if it is not able to find them it ends trying to walk resources of
the ACPI namespace root object itself.
This object has all-ones handle, which causes a NULL pointer dereference
in the ACPI code (from dereferencing this pointer with an offset).
This in turn causes an oops on boot with VMBus host implementations that do
not provide Hyper-V MMIO ranges in their VMBus ACPI device or its
ancestors.
The QEMU VMBus implementation is an example of such implementation.
I guess providing these ranges is optional, since all tested Windows
versions seem to be able to use VMBus devices without them.
Fix this by explicitly terminating the lookup at the ACPI namespace root
object.
Note that Linux guests under KVM/QEMU do not use the Hyper-V PV interface
by default - they only do so if the KVM PV interface is missing or
disabled.
Example stack trace of such oops:
[ 3.710827] ? __die+0x1f/0x60
[ 3.715030] ? page_fault_oops+0x159/0x460
[ 3.716008] ? exc_page_fault+0x73/0x170
[ 3.716959] ? asm_exc_page_fault+0x22/0x30
[ 3.717957] ? acpi_ns_lookup+0x7a/0x4b0
[ 3.718898] ? acpi_ns_internalize_name+0x79/0xc0
[ 3.720018] acpi_ns_get_node_unlocked+0xb5/0xe0
[ 3.721120] ? acpi_ns_check_object_type+0xfe/0x200
[ 3.722285] ? acpi_rs_convert_aml_to_resource+0x37/0x6e0
[ 3.723559] ? down_timeout+0x3a/0x60
[ 3.724455] ? acpi_ns_get_node+0x3a/0x60
[ 3.725412] acpi_ns_get_node+0x3a/0x60
[ 3.726335] acpi_ns_evaluate+0x1c3/0x2c0
[ 3.727295] acpi_ut_evaluate_object+0x64/0x1b0
[ 3.728400] acpi_rs_get_method_data+0x2b/0x70
[ 3.729476] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus]
[ 3.730940] ? vmbus_platform_driver_probe+0x1d0/0x1d0 [hv_vmbus]
[ 3.732411] acpi_walk_resources+0x78/0xd0
[ 3.733398] vmbus_platform_driver_probe+0x9f/0x1d0 [hv_vmbus]
[ 3.734802] platform_probe+0x3d/0x90
[ 3.735684] really_probe+0x19b/0x400
[ 3.736570] ? __device_attach_driver+0x100/0x100
[ 3.737697] __driver_probe_device+0x78/0x160
[ 3.738746] driver_probe_device+0x1f/0x90
[ 3.739743] __driver_attach+0xc2/0x1b0
[ 3.740671] bus_for_each_dev+0x70/0xc0
[ 3.741601] bus_add_driver+0x10e/0x210
[ 3.742527] driver_register+0x55/0xf0
[ 3.744412] ? 0xffffffffc039a000
[ 3.745207] hv_acpi_init+0x3c/0x1000 [hv_vmbus]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
Input: exc3000 - properly stop timer on shutdown
We need to stop the timer on driver unbind or probe failures, otherwise
we get UAF/Oops.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: fix wrong ct->timeout value
(struct nf_conn)->timeout is an interval before the conntrack
confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack:
- Set by calling ctnetlink_change_timeout(). As a result,
`nfct_time_stamp` was wrongly added to `ct->timeout` twice.
- Get by calling ctnetlink_dump_timeout(). As a result,
`nfct_time_stamp` was wrongly subtracted.
Call Trace:
<TASK>
dump_stack_lvl
ctnetlink_dump_timeout
__ctnetlink_glue_build
ctnetlink_glue_build
__nfqnl_enqueue_packet
nf_queue
nf_hook_slow
ip_mc_output
? __pfx_ip_finish_output
ip_send_skb
? __pfx_dst_output
udp_send_skb
udp_sendmsg
? __pfx_ip_generic_getfrag
sock_sendmsg
Separate the 2 cases in:
- Setting `ct->timeout` in __nf_ct_set_timeout().
- Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is
set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the
introduction of the nfnetlink_queue conntrack support, select a
sufficiently old Fixes: tag for -stable kernel to pick up this fix.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_fq: fix integer overflow of "credit"
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gvt: fix vgpu debugfs clean in remove
Check carefully on root debugfs available when destroying vgpu,
e.g in remove case drm minor's debugfs root might already be destroyed,
which led to kernel oops like below.
Console: switching to colour dummy device 80x25
i915 0000:00:02.0: MDEV: Unregistering
intel_vgpu_mdev b1338b2d-a709-4c23-b766-cc436c36cdf0: Removing from iommu group 14
BUG: kernel NULL pointer dereference, address: 0000000000000150
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 3 PID: 1046 Comm: driverctl Not tainted 6.1.0-rc2+ #6
Hardware name: HP HP ProDesk 600 G3 MT/829D, BIOS P02 Ver. 02.44 09/13/2022
RIP: 0010:__lock_acquire+0x5e2/0x1f90
Code: 87 ad 09 00 00 39 05 e1 1e cc 02 0f 82 f1 09 00 00 ba 01 00 00 00 48 83 c4 48 89 d0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ff <48> 81 3f 60 9e c2 b6 45 0f 45 f8 83 fe 01 0f 87 55 fa ff ff 89 f0
RSP: 0018:ffff9f770274f948 EFLAGS: 00010046
RAX: 0000000000000003 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000150
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8895d1173300 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000150 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fc9b2ba0740(0000) GS:ffff889cdfcc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000150 CR3: 000000010fd93005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0xbf/0x2b0
? simple_recursive_removal+0xa5/0x2b0
? lock_release+0x13d/0x2d0
down_write+0x2a/0xd0
? simple_recursive_removal+0xa5/0x2b0
simple_recursive_removal+0xa5/0x2b0
? start_creating.part.0+0x110/0x110
? _raw_spin_unlock+0x29/0x40
debugfs_remove+0x40/0x60
intel_gvt_debugfs_remove_vgpu+0x15/0x30 [kvmgt]
intel_gvt_destroy_vgpu+0x60/0x100 [kvmgt]
intel_vgpu_release_dev+0xe/0x20 [kvmgt]
device_release+0x30/0x80
kobject_put+0x79/0x1b0
device_release_driver_internal+0x1b8/0x230
bus_remove_device+0xec/0x160
device_del+0x189/0x400
? up_write+0x9c/0x1b0
? mdev_device_remove_common+0x60/0x60 [mdev]
mdev_device_remove_common+0x22/0x60 [mdev]
mdev_device_remove_cb+0x17/0x20 [mdev]
device_for_each_child+0x56/0x80
mdev_unregister_parent+0x5a/0x81 [mdev]
intel_gvt_clean_device+0x2d/0xe0 [kvmgt]
intel_gvt_driver_remove+0x2e/0xb0 [i915]
i915_driver_remove+0xac/0x100 [i915]
i915_pci_remove+0x1a/0x30 [i915]
pci_device_remove+0x31/0xa0
device_release_driver_internal+0x1b8/0x230
unbind_store+0xd8/0x100
kernfs_fop_write_iter+0x156/0x210
vfs_write+0x236/0x4a0
ksys_write+0x61/0xd0
do_syscall_64+0x55/0x80
? find_held_lock+0x2b/0x80
? lock_release+0x13d/0x2d0
? up_read+0x17/0x20
? lock_is_held_type+0xe3/0x140
? asm_exc_page_fault+0x22/0x30
? lockdep_hardirqs_on+0x7d/0x100
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fc9b2c9e0c4
Code: 15 71 7d 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 80 3d 3d 05 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48
RSP: 002b:00007ffec29c81c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007fc9b2c9e0c4
RDX: 000000000000000d RSI: 0000559f8b5f48a0 RDI: 0000000000000001
RBP: 0000559f8b5f48a0 R08: 0000559f8b5f3540 R09: 00007fc9b2d76d30
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000d
R13: 00007fc9b2d77780 R14: 000000000000000d R15: 00007fc9b2d72a00
</TASK>
Modules linked in: sunrpc intel_rapl_msr intel_rapl_common intel_pmc_core_pltdrv intel_pmc_core intel_tcc_cooling x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ee1004 igbvf rapl vfat fat intel_cstate intel_uncore pktcdvd i2c_i801 pcspkr wmi_bmof i2c_smbus acpi_pad vfio_pci vfio_pci_core vfio_virqfd zram fuse dm
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
scsi: hisi_sas: Grab sas_dev lock when traversing the members of sas_dev.list
When freeing slots in function slot_complete_v3_hw(), it is possible that
sas_dev.list is being traversed elsewhere, and it may trigger a NULL
pointer exception, such as follows:
==>cq thread ==>scsi_eh_6
==>scsi_error_handler()
==>sas_eh_handle_sas_errors()
==>sas_scsi_find_task()
==>lldd_abort_task()
==>slot_complete_v3_hw() ==>hisi_sas_abort_task()
==>hisi_sas_slot_task_free() ==>dereg_device_v3_hw()
==>list_del_init() ==>list_for_each_entry_safe()
[ 7165.434918] sas: Enter sas_scsi_recover_host busy: 32 failed: 32
[ 7165.434926] sas: trying to find task 0x00000000769b5ba5
[ 7165.434927] sas: sas_scsi_find_task: aborting task 0x00000000769b5ba5
[ 7165.434940] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000769b5ba5) aborted
[ 7165.434964] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000c9f7aa07) ignored
[ 7165.434965] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000e2a1cf01) ignored
[ 7165.434968] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 7165.434972] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(0000000022d52d93) ignored
[ 7165.434975] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(0000000066a7516c) ignored
[ 7165.434976] Mem abort info:
[ 7165.434982] ESR = 0x96000004
[ 7165.434991] Exception class = DABT (current EL), IL = 32 bits
[ 7165.434992] SET = 0, FnV = 0
[ 7165.434993] EA = 0, S1PTW = 0
[ 7165.434994] Data abort info:
[ 7165.434994] ISV = 0, ISS = 0x00000004
[ 7165.434995] CM = 0, WnR = 0
[ 7165.434997] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f29543f2
[ 7165.434998] [0000000000000000] pgd=0000000000000000
[ 7165.435003] Internal error: Oops: 96000004 [#1] SMP
[ 7165.439863] Process scsi_eh_6 (pid: 4109, stack limit = 0x00000000c43818d5)
[ 7165.468862] pstate: 00c00009 (nzcv daif +PAN +UAO)
[ 7165.473637] pc : dereg_device_v3_hw+0x68/0xa8 [hisi_sas_v3_hw]
[ 7165.479443] lr : dereg_device_v3_hw+0x2c/0xa8 [hisi_sas_v3_hw]
[ 7165.485247] sp : ffff00001d623bc0
[ 7165.488546] x29: ffff00001d623bc0 x28: ffffa027d03b9508
[ 7165.493835] x27: ffff80278ed50af0 x26: ffffa027dd31e0a8
[ 7165.499123] x25: ffffa027d9b27f88 x24: ffffa027d9b209f8
[ 7165.504411] x23: ffffa027c45b0d60 x22: ffff80278ec07c00
[ 7165.509700] x21: 0000000000000008 x20: ffffa027d9b209f8
[ 7165.514988] x19: ffffa027d9b27f88 x18: ffffffffffffffff
[ 7165.520276] x17: 0000000000000000 x16: 0000000000000000
[ 7165.525564] x15: ffff0000091d9708 x14: ffff0000093b7dc8
[ 7165.530852] x13: ffff0000093b7a23 x12: 6e7265746e692067
[ 7165.536140] x11: 0000000000000000 x10: 0000000000000bb0
[ 7165.541429] x9 : ffff00001d6238f0 x8 : ffffa027d877af00
[ 7165.546718] x7 : ffffa027d6329600 x6 : ffff7e809f58ca00
[ 7165.552006] x5 : 0000000000001f8a x4 : 000000000000088e
[ 7165.557295] x3 : ffffa027d9b27fa8 x2 : 0000000000000000
[ 7165.562583] x1 : 0000000000000000 x0 : 000000003000188e
[ 7165.567872] Call trace:
[ 7165.570309] dereg_device_v3_hw+0x68/0xa8 [hisi_sas_v3_hw]
[ 7165.575775] hisi_sas_abort_task+0x248/0x358 [hisi_sas_main]
[ 7165.581415] sas_eh_handle_sas_errors+0x258/0x8e0 [libsas]
[ 7165.586876] sas_scsi_recover_host+0x134/0x458 [libsas]
[ 7165.592082] scsi_error_handler+0xb4/0x488
[ 7165.596163] kthread+0x134/0x138
[ 7165.599380] ret_from_fork+0x10/0x18
[ 7165.602940] Code: d5033e9f b9000040 aa0103e2 eb03003f (f9400021)
[ 7165.609004] kernel fault(0x1) notification starting on CPU 75
[ 7165.700728] ---[ end trace fc042cbbea224efc ]---
[ 7165.705326] Kernel panic - not syncing: Fatal exception
To fix the issue, grab sas_dev lock when traversing the members of
sas_dev.list in dereg_device_v3_hw() and hisi_sas_release_tasks() to avoid
concurrency of adding and deleting member. When
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
btrfs: reject invalid reloc tree root keys with stack dump
[BUG]
Syzbot reported a crash that an ASSERT() got triggered inside
prepare_to_merge().
That ASSERT() makes sure the reloc tree is properly pointed back by its
subvolume tree.
[CAUSE]
After more debugging output, it turns out we had an invalid reloc tree:
BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17
Note the above root key is (TREE_RELOC_OBJECTID, ROOT_ITEM,
QUOTA_TREE_OBJECTID), meaning it's a reloc tree for quota tree.
But reloc trees can only exist for subvolumes, as for non-subvolume
trees, we just COW the involved tree block, no need to create a reloc
tree since those tree blocks won't be shared with other trees.
Only subvolumes tree can share tree blocks with other trees (thus they
have BTRFS_ROOT_SHAREABLE flag).
Thus this new debug output proves my previous assumption that corrupted
on-disk data can trigger that ASSERT().
[FIX]
Besides the dedicated fix and the graceful exit, also let tree-checker to
check such root keys, to make sure reloc trees can only exist for subvolumes.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07