Linux: >> Linux Kernel >> 6.1.139 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
mm/thp: fix deferred split unqueue naming and locking
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without). The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.
Before fixing locking: rename misleading folio_undo_large_rmappable(),
which does not undo large_rmappable, to folio_unqueue_deferred_split(),
which is what it does. But that and its out-of-line __callee are mm
internals of very limited usability: add comment and WARN_ON_ONCEs to
check usage; and return a bool to say if a deferred split was unqueued,
which can then be used in WARN_ON_ONCEs around safety checks (sparing
callers the arcane conditionals in __folio_unqueue_deferred_split()).
Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all
of whose callers now call it beforehand (and if any forget then bad_page()
will tell) - except for its caller put_pages_list(), which itself no
longer has any callers (and will be deleted separately).
Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0
without checking and unqueueing a THP folio from deferred split list;
which is unfortunate, since the split_queue_lock depends on the memcg
(when memcg is enabled); so swapout has been unqueueing such THPs later,
when freeing the folio, using the pgdat's lock instead: potentially
corrupting the memcg's list. __remove_mapping() has frozen refcount to 0
here, so no problem with calling folio_unqueue_deferred_split() before
resetting memcg_data.
That goes back to 5.4 commit 87eaceb3faa5 ("mm: thp: make deferred split
shrinker memcg aware"): which included a check on swapcache before adding
to deferred queue, but no check on deferred queue before adding THP to
swapcache. That worked fine with the usual sequence of events in reclaim
(though there were a couple of rare ways in which a THP on deferred queue
could have been swapped out), but 6.12 commit dafff3f4c850 ("mm: split
underused THPs") avoids splitting underused THPs in reclaim, which makes
swapcache THPs on deferred queue commonplace.
Keep the check on swapcache before adding to deferred queue? Yes: it is
no longer essential, but preserves the existing behaviour, and is likely
to be a worthwhile optimization (vmstat showed much more traffic on the
queue under swapping load if the check was removed); update its comment.
Memcg-v1 move (deprecated): mem_cgroup_move_account() has been changing
folio->memcg_data without checking and unqueueing a THP folio from the
deferred list, sometimes corrupting "from" memcg's list, like swapout.
Refcount is non-zero here, so folio_unqueue_deferred_split() can only be
used in a WARN_ON_ONCE to validate the fix, which must be done earlier:
mem_cgroup_move_charge_pte_range() first try to split the THP (splitting
of course unqueues), or skip it if that fails. Not ideal, but moving
charge has been requested, and khugepaged should repair the THP later:
nobody wants new custom unqueueing code just for this deprecated case.
The 87eaceb3faa5 commit did have the code to move from one deferred list
to another (but was not conscious of its unsafety while refcount non-0);
but that was removed by 5.6 commit fac0516b5534 ("mm: thp: don't need care
deferred split queue in memcg charge move path"), which argued that the
existence of a PMD mapping guarantees that the THP cannot be on a deferred
list. As above, false in rare cases, and now commonly false.
Backport to 6.11 should be straightforward. Earlier backports must take
care that other _deferred_list fixes and dependencies are included. There
is not a strong case for backports, but they can fix cornercases.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/imagination: Break an object reference loop
When remaining resources are being cleaned up on driver close,
outstanding VM mappings may result in resources being leaked, due
to an object reference loop, as shown below, with each object (or
set of objects) referencing the object below it:
PVR GEM Object
GPU scheduler "finished" fence
GPU scheduler “scheduled” fence
PVR driver “done” fence
PVR Context
PVR VM Context
PVR VM Mappings
PVR GEM Object
The reference that the PVR VM Context has on the VM mappings is a
soft one, in the sense that the freeing of outstanding VM mappings
is done as part of VM context destruction; no reference counts are
involved, as is the case for all the other references in the loop.
To break the reference loop during cleanup, free the outstanding
VM mappings before destroying the PVR Context associated with the
VM context.
CVSS Score
5.5
EPSS Score
0.001
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Fix slab-use-after-free in scmi_bus_notifier()
The scmi_dev->name is released prematurely in __scmi_device_destroy(),
which causes slab-use-after-free when accessing scmi_dev->name in
scmi_bus_notifier(). So move the release of scmi_dev->name to
scmi_device_release() to avoid slab-use-after-free.
| BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
| Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
|
| CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1
| Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT)
| Call trace:
| dump_backtrace+0x94/0x114
| show_stack+0x18/0x24
| dump_stack_lvl+0x48/0x60
| print_report+0xf4/0x5b0
| kasan_report+0xa4/0xec
| __asan_report_load1_noabort+0x20/0x2c
| strncmp+0xe4/0xec
| scmi_bus_notifier+0x5c/0x54c
| notifier_call_chain+0xb4/0x31c
| blocking_notifier_call_chain+0x68/0x9c
| bus_notify+0x54/0x78
| device_del+0x1bc/0x840
| device_unregister+0x20/0xb4
| __scmi_device_destroy+0xac/0x280
| scmi_device_destroy+0x94/0xd0
| scmi_chan_setup+0x524/0x750
| scmi_probe+0x7fc/0x1508
| platform_probe+0xc4/0x19c
| really_probe+0x32c/0x99c
| __driver_probe_device+0x15c/0x3c4
| driver_probe_device+0x5c/0x170
| __driver_attach+0x1c8/0x440
| bus_for_each_dev+0xf4/0x178
| driver_attach+0x3c/0x58
| bus_add_driver+0x234/0x4d4
| driver_register+0xf4/0x3c0
| __platform_driver_register+0x60/0x88
| scmi_driver_init+0xb0/0x104
| do_one_initcall+0xb4/0x664
| kernel_init_freeable+0x3c8/0x894
| kernel_init+0x24/0x1e8
| ret_from_fork+0x10/0x20
|
| Allocated by task 1:
| kasan_save_stack+0x2c/0x54
| kasan_set_track+0x2c/0x40
| kasan_save_alloc_info+0x24/0x34
| __kasan_kmalloc+0xa0/0xb8
| __kmalloc_node_track_caller+0x6c/0x104
| kstrdup+0x48/0x84
| kstrdup_const+0x34/0x40
| __scmi_device_create.part.0+0x8c/0x408
| scmi_device_create+0x104/0x370
| scmi_chan_setup+0x2a0/0x750
| scmi_probe+0x7fc/0x1508
| platform_probe+0xc4/0x19c
| really_probe+0x32c/0x99c
| __driver_probe_device+0x15c/0x3c4
| driver_probe_device+0x5c/0x170
| __driver_attach+0x1c8/0x440
| bus_for_each_dev+0xf4/0x178
| driver_attach+0x3c/0x58
| bus_add_driver+0x234/0x4d4
| driver_register+0xf4/0x3c0
| __platform_driver_register+0x60/0x88
| scmi_driver_init+0xb0/0x104
| do_one_initcall+0xb4/0x664
| kernel_init_freeable+0x3c8/0x894
| kernel_init+0x24/0x1e8
| ret_from_fork+0x10/0x20
|
| Freed by task 1:
| kasan_save_stack+0x2c/0x54
| kasan_set_track+0x2c/0x40
| kasan_save_free_info+0x38/0x5c
| __kasan_slab_free+0xe8/0x164
| __kmem_cache_free+0x11c/0x230
| kfree+0x70/0x130
| kfree_const+0x20/0x40
| __scmi_device_destroy+0x70/0x280
| scmi_device_destroy+0x94/0xd0
| scmi_chan_setup+0x524/0x750
| scmi_probe+0x7fc/0x1508
| platform_probe+0xc4/0x19c
| really_probe+0x32c/0x99c
| __driver_probe_device+0x15c/0x3c4
| driver_probe_device+0x5c/0x170
| __driver_attach+0x1c8/0x440
| bus_for_each_dev+0xf4/0x178
| driver_attach+0x3c/0x58
| bus_add_driver+0x234/0x4d4
| driver_register+0xf4/0x3c0
| __platform_driver_register+0x60/0x88
| scmi_driver_init+0xb0/0x104
| do_one_initcall+0xb4/0x664
| kernel_init_freeable+0x3c8/0x894
| kernel_init+0x24/0x1e8
| ret_from_fork+0x10/0x20
CVSS Score
7.8
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/hdcp: Add encoder check in hdcp2_get_capability
Add encoder check in intel_hdcp2_get_capability to avoid
null pointer error.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/hdcp: Add encoder check in intel_hdcp_get_capability
Sometimes during hotplug scenario or suspend/resume scenario encoder is
not always initialized when intel_hdcp_get_capability add
a check to avoid kernel null pointer dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: Fix potential NULL dereference in mtk_crtc_destroy()
In mtk_crtc_create(), if the call to mbox_request_channel() fails then we
set the "mtk_crtc->cmdq_client.chan" pointer to NULL. In that situation,
we do not call cmdq_pkt_create().
During the cleanup, we need to check if the "mtk_crtc->cmdq_client.chan"
is NULL first before calling cmdq_pkt_destroy(). Calling
cmdq_pkt_destroy() is unnecessary if we didn't call cmdq_pkt_create() and
it will result in a NULL pointer dereference.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()
The per-netns IP tunnel hash table is protected by the RTNL mutex and
ip_tunnel_find() is only called from the control path where the mutex is
taken.
Add a lockdep expression to hlist_for_each_entry_rcu() in
ip_tunnel_find() in order to validate that the mutex is held and to
silence the suspicious RCU usage warning [1].
[1]
WARNING: suspicious RCU usage
6.12.0-rc3-custom-gd95d9a31aceb #139 Not tainted
-----------------------------
net/ipv4/ip_tunnel.c:221 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/362:
#0: ffffffff86fc7cb0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x377/0xf60
stack backtrace:
CPU: 12 UID: 0 PID: 362 Comm: ip Not tainted 6.12.0-rc3-custom-gd95d9a31aceb #139
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0xba/0x110
lockdep_rcu_suspicious.cold+0x4f/0xd6
ip_tunnel_find+0x435/0x4d0
ip_tunnel_newlink+0x517/0x7a0
ipgre_newlink+0x14c/0x170
__rtnl_newlink+0x1173/0x19c0
rtnl_newlink+0x6c/0xa0
rtnetlink_rcv_msg+0x3cc/0xf60
netlink_rcv_skb+0x171/0x450
netlink_unicast+0x539/0x7f0
netlink_sendmsg+0x8c1/0xd80
____sys_sendmsg+0x8f9/0xc20
___sys_sendmsg+0x197/0x1e0
__sys_sendmsg+0x122/0x1f0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
media: av7110: fix a spectre vulnerability
As warned by smatch:
drivers/staging/media/av7110/av7110_ca.c:270 dvb_ca_ioctl() warn: potential spectre issue 'av7110->ci_slot' [w] (local cap)
There is a spectre-related vulnerability at the code. Fix it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
net: enetc: allocate vf_state during PF probes
In the previous implementation, vf_state is allocated memory only when VF
is enabled. However, net_device_ops::ndo_set_vf_mac() may be called before
VF is enabled to configure the MAC address of VF. If this is the case,
enetc_pf_set_vf_mac() will access vf_state, resulting in access to a null
pointer. The simplified error log is as follows.
root@ls1028ardb:~# ip link set eno0 vf 1 mac 00:0c:e7:66:77:89
[ 173.543315] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
[ 173.637254] pc : enetc_pf_set_vf_mac+0x3c/0x80 Message from sy
[ 173.641973] lr : do_setlink+0x4a8/0xec8
[ 173.732292] Call trace:
[ 173.734740] enetc_pf_set_vf_mac+0x3c/0x80
[ 173.738847] __rtnl_newlink+0x530/0x89c
[ 173.742692] rtnl_newlink+0x50/0x7c
[ 173.746189] rtnetlink_rcv_msg+0x128/0x390
[ 173.750298] netlink_rcv_skb+0x60/0x130
[ 173.754145] rtnetlink_rcv+0x18/0x24
[ 173.757731] netlink_unicast+0x318/0x380
[ 173.761665] netlink_sendmsg+0x17c/0x3c8
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
dm: fix a crash if blk_alloc_disk fails
If blk_alloc_disk fails, the variable md->disk is set to an error value.
cleanup_mapped_device will see that md->disk is non-NULL and it will
attempt to access it, causing a crash on this statement
"md->disk->private_data = NULL;".
CVSS Score
4.7
EPSS Score
0.0
Published
2024-11-19