Security Vulnerabilities - CVEs Published In 2024
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
7.8
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/panthor: Lock XArray when getting entries for the VM
Similar to commit cac075706f29 ("drm/panthor: Fix race when converting
group handle to group object") we need to use the XArray's internal
locking when retrieving a vm pointer from there.
v2: Removed part of the patch that was trying to protect fetching
the heap pointer from XArray, as that operation is protected by
the @pool->lock.
CVSS Score
7.8
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
media: ar0521: don't overflow when checking PLL values
The PLL checks are comparing 64 bit integers with 32 bit
ones, as reported by Coverity. Depending on the values of
the variables, this may underflow.
Fix it ensuring that both sides of the expression are u64.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
virtio_net: Add hash_key_length check
Add hash_key_length check in virtnet_probe() to avoid possible out of
bound errors when setting/reading the hash key.
CVSS Score
8.4
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: qcom-pmic: init value of hdr_len/txbuf_len earlier
If the read of USB_PDPHY_RX_ACKNOWLEDGE_REG failed, then hdr_len and
txbuf_len are uninitialized. This commit stops to print uninitialized
value and misleading/false data.
CVSS Score
5.5
EPSS Score
0.002
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
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
tpm: Lock TPM chip in tpm_pm_suspend() first
Setting TPM_CHIP_FLAG_SUSPENDED in the end of tpm_pm_suspend() can be racy
according, as this leaves window for tpm_hwrng_read() to be called while
the operation is in progress. The recent bug report gives also evidence of
this behaviour.
Aadress this by locking the TPM chip before checking any chip->flags both
in tpm_pm_suspend() and tpm_hwrng_read(). Move TPM_CHIP_FLAG_SUSPENDED
check inside tpm_get_random() so that it will be always checked only when
the lock is reserved.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Drop VM dma-resv lock on xe_sync_in_fence_get failure in exec IOCTL
Upon failure all locks need to be dropped before returning to the user.
(cherry picked from commit 7d1a4258e602ffdce529f56686925034c1b3b095)
CVSS Score
5.5
EPSS Score
0.001
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Fix possible exec queue leak in exec IOCTL
In a couple of places after an exec queue is looked up the exec IOCTL
returns on input errors without dropping the exec queue ref. Fix this
ensuring the exec queue ref is dropped on input error.
(cherry picked from commit 07064a200b40ac2195cb6b7b779897d9377e5e6f)
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-19
In the Linux kernel, the following vulnerability has been resolved:
i40e: fix race condition by adding filter's intermediate sync state
Fix a race condition in the i40e driver that leads to MAC/VLAN filters
becoming corrupted and leaking. Address the issue that occurs under
heavy load when multiple threads are concurrently modifying MAC/VLAN
filters by setting mac and port VLAN.
1. Thread T0 allocates a filter in i40e_add_filter() within
i40e_ndo_set_vf_port_vlan().
2. Thread T1 concurrently frees the filter in __i40e_del_filter() within
i40e_ndo_set_vf_mac().
3. Subsequently, i40e_service_task() calls i40e_sync_vsi_filters(), which
refers to the already freed filter memory, causing corruption.
Reproduction steps:
1. Spawn multiple VFs.
2. Apply a concurrent heavy load by running parallel operations to change
MAC addresses on the VFs and change port VLANs on the host.
3. Observe errors in dmesg:
"Error I40E_AQ_RC_ENOSPC adding RX filters on VF XX,
please set promiscuous on manually for VF XX".
Exact code for stable reproduction Intel can't open-source now.
The fix involves implementing a new intermediate filter state,
I40E_FILTER_NEW_SYNC, for the time when a filter is on a tmp_add_list.
These filters cannot be deleted from the hash list directly but
must be removed using the full process.
CVSS Score
7.8
EPSS Score
0.002
Published
2024-11-19