Linux: >> Linux Kernel >> 4.19.321 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
srcu: Use irq_work to start GP in tiny SRCU
Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(),
which acquires the workqueue pool->lock.
This causes a lockdep splat when call_srcu() is called with a scheduler
lock held, due to:
call_srcu() [holding pi_lock]
srcu_gp_start_if_needed()
schedule_work() -> pool->lock
workqueue_init() / create_worker() [holding pool->lock]
wake_up_process() -> try_to_wake_up() -> pi_lock
Also add irq_work_sync() to cleanup_srcu_struct() to prevent a
use-after-free if a queued irq_work fires after cleanup begins.
Tested with rcutorture SRCU-T and no lockdep warnings.
[ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work
to start process_srcu()" ]
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: ensure safe access to master conntrack
Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp->master invalid.
To access exp->master safely:
- Grab the nf_conntrack_expect_lock, this gets serialized with
clean_from_lists() which also holds this lock when the master
conntrack goes away.
- Hold reference on master conntrack via nf_conntrack_find_get().
Not so easy since the master tuple to look up for the master conntrack
is not available in the existing problematic paths.
This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.
The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().
However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.
The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.
For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp->master.
While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()
If overlay is used on top of btrfs, dentry->d_sb translates to overlay's
super block and fsid assignment will lead to a crash.
Use file_inode(file)->i_sb to always get btrfs_sb.
CVSS Score
9.1
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix zero size inode with non-zero size after log replay
When logging that an inode exists, as part of logging a new name or
logging new dir entries for a directory, we always set the generation of
the logged inode item to 0. This is to signal during log replay (in
overwrite_item()), that we should not set the i_size since we only logged
that an inode exists, so the i_size of the inode in the subvolume tree
must be preserved (as when we log new names or that an inode exists, we
don't log extents).
This works fine except when we have already logged an inode in full mode
or it's the first time we are logging an inode created in a past
transaction, that inode has a new i_size of 0 and then we log a new name
for the inode (due to a new hardlink or a rename), in which case we log
an i_size of 0 for the inode and a generation of 0, which causes the log
replay code to not update the inode's i_size to 0 (in overwrite_item()).
An example scenario:
mkdir /mnt/dir
xfs_io -f -c "pwrite 0 64K" /mnt/dir/foo
sync
xfs_io -c "truncate 0" -c "fsync" /mnt/dir/foo
ln /mnt/dir/foo /mnt/dir/bar
xfs_io -c "fsync" /mnt/dir
<power fail>
After log replay the file remains with a size of 64K. This is because when
we first log the inode, when we fsync file foo, we log its current i_size
of 0, and then when we create a hard link we log again the inode in exists
mode (LOG_INODE_EXISTS) but we set a generation of 0 for the inode item we
add to the log tree, so during log replay overwrite_item() sees that the
generation is 0 and i_size is 0 so we skip updating the inode's i_size
from 64K to 0.
Fix this by making sure at fill_inode_item() we always log the real
generation of the inode if it was logged in the current transaction with
the i_size we logged before. Also if an inode created in a previous
transaction is logged in exists mode only, make sure we log the i_size
stored in the inode item located from the commit root, so that if we log
multiple times that the inode exists we get the correct i_size.
A test case for fstests will follow soon.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Fix memory leak of BO array in hang state
The hang state's BO array is allocated separately with kzalloc() in
vc4_save_hang_state() but never freed in vc4_free_hang_state(). Add the
missing kfree() for the BO array before freeing the hang state struct.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
xfrm: account XFRMA_IF_ID in aevent size calculation
xfrm_get_ae() allocates the reply skb with xfrm_aevent_msgsize(), then
build_aevent() appends attributes including XFRMA_IF_ID when x->if_id is
set.
xfrm_aevent_msgsize() does not include space for XFRMA_IF_ID. For states
with if_id, build_aevent() can fail with -EMSGSIZE and hit BUG_ON(err < 0)
in xfrm_get_ae(), turning a malformed netlink interaction into a kernel
panic.
Account XFRMA_IF_ID in the size calculation unconditionally and replace
the BUG_ON with normal error unwinding.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: validate bsscfg indices in IF events
brcmf_fweh_handle_if_event() validates the firmware-provided interface
index before it touches drvr->iflist[], but it still uses the raw
bsscfgidx field as an array index without a matching range check.
Reject IF events whose bsscfg index does not fit in drvr->iflist[]
before indexing the interface array.
[add missing wifi prefix]
CVSS Score
8.8
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
HID: roccat: fix use-after-free in roccat_report_event
roccat_report_event() iterates over the device->readers list without
holding the readers_lock. This allows a concurrent roccat_release() to
remove and free a reader while it's still being accessed, leading to a
use-after-free.
Protect the readers list traversal with the readers_lock mutex.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
net: lapbether: handle NETDEV_PRE_TYPE_CHANGE
lapbeth_data_transmit() expects the underlying device type
to be ARPHRD_ETHER.
Returning NOTIFY_BAD from lapbeth_device_event() makes sure
bonding driver can not break this expectation.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Fix a memory leak in hang state error path
When vc4_save_hang_state() encounters an early return condition, it
returns without freeing the previously allocated `kernel_state`,
leaking memory.
Add the missing kfree() calls by consolidating the early return paths
into a single place.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-06