Linux: >> Linux Kernel >> 4.19.147 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by concurrent atomic commit and checkpoint writes
During SPO tests, when mounting F2FS, an -EINVAL error was returned from
f2fs_recover_inode_page. The issue occurred under the following scenario
Thread A Thread B
f2fs_ioc_commit_atomic_write
- f2fs_do_sync_file // atomic = true
- f2fs_fsync_node_pages
: last_folio = inode folio
: schedule before folio_lock(last_folio) f2fs_write_checkpoint
- block_operations// writeback last_folio
- schedule before f2fs_flush_nat_entries
: set_fsync_mark(last_folio, 1)
: set_dentry_mark(last_folio, 1)
: folio_mark_dirty(last_folio)
- __write_node_folio(last_folio)
: f2fs_down_read(&sbi->node_write)//block
- f2fs_flush_nat_entries
: {struct nat_entry}->flag |= BIT(IS_CHECKPOINTED)
- unblock_operations
: f2fs_up_write(&sbi->node_write)
f2fs_write_checkpoint//return
: f2fs_do_write_node_page()
f2fs_ioc_commit_atomic_write//return
SPO
Thread A calls f2fs_need_dentry_mark(sbi, ino), and the last_folio has
already been written once. However, the {struct nat_entry}->flag did not
have the IS_CHECKPOINTED set, causing set_dentry_mark(last_folio, 1) and
write last_folio again after Thread B finishes f2fs_write_checkpoint.
After SPO and reboot, it was detected that {struct node_info}->blk_addr
was not NULL_ADDR because Thread B successfully write the checkpoint.
This issue only occurs in atomic write scenarios. For regular file
fsync operations, the folio must be dirty. If
block_operations->f2fs_sync_node_pages successfully submit the folio
write, this path will not be executed. Otherwise, the
f2fs_write_checkpoint will need to wait for the folio write submission
to complete, as sbi->nr_pages[F2FS_DIRTY_NODES] > 0. Therefore, the
situation where f2fs_need_dentry_mark checks that the {struct
nat_entry}->flag /wo the IS_CHECKPOINTED flag, but the folio write has
already been submitted, will not occur.
Therefore, for atomic file fsync, sbi->node_write should be acquired
through __write_node_folio to ensure that the IS_CHECKPOINTED flag
correctly indicates that the checkpoint write has been completed.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix unprivileged local user can do privileged policy management
An unprivileged local user can load, replace, and remove profiles by
opening the apparmorfs interfaces, via a confused deputy attack, by
passing the opened fd to a privileged process, and getting the
privileged process to write to the interface.
This does require a privileged target that can be manipulated to do
the write for the unprivileged process, but once such access is
achieved full policy management is possible and all the possible
implications that implies: removing confinement, DoS of system or
target applications by denying all execution, by-passing the
unprivileged user namespace restriction, to exploiting kernel bugs for
a local privilege escalation.
The policy management interface can not have its permissions simply
changed from 0666 to 0600 because non-root processes need to be able
to load policy to different policy namespaces.
Instead ensure the task writing the interface has privileges that
are a subset of the task that opened the interface. This is already
done via policy for confined processes, but unconfined can delegate
access to the opened fd, by-passing the usual policy check.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
apparmor: validate DFA start states are in bounds in unpack_pdb
Start states are read from untrusted data and used as indexes into the
DFA state tables. The aa_dfa_next() function call in unpack_pdb() will
access dfa->tables[YYTD_ID_BASE][start], and if the start state exceeds
the number of states in the DFA, this results in an out-of-bound read.
==================================================================
BUG: KASAN: slab-out-of-bounds in aa_dfa_next+0x2a1/0x360
Read of size 4 at addr ffff88811956fb90 by task su/1097
...
Reject policies with out-of-bounds start states during unpacking
to prevent the issue.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
net: liquidio: Initialize netdev pointer before queue setup
In setup_nic_devices(), the netdev is allocated using alloc_etherdev_mq().
However, the pointer to this structure is stored in oct->props[i].netdev
only after the calls to netif_set_real_num_rx_queues() and
netif_set_real_num_tx_queues().
If either of these functions fails, setup_nic_devices() returns an error
without freeing the allocated netdev. Since oct->props[i].netdev is still
NULL at this point, the cleanup function liquidio_destroy_nic_device()
will fail to find and free the netdev, resulting in a memory leak.
Fix this by initializing oct->props[i].netdev before calling the queue
setup functions. This ensures that the netdev is properly accessible for
cleanup in case of errors.
Compile tested only. Issue found using a prototype static analysis tool
and code review.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
media: dvb-core: fix wrong reinitialization of ringbuffer on reopen
dvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the
DVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which
reinitializes the waitqueue list head to empty.
Since dmxdev->dvr_buffer.queue is a shared waitqueue (all opens of the
same DVR device share it), this orphans any existing waitqueue entries
from io_uring poll or epoll, leaving them with stale prev/next pointers
while the list head is reset to {self, self}.
The waitqueue and spinlock in dvr_buffer are already properly
initialized once in dvb_dmxdev_init(). The open path only needs to
reset the buffer data pointer, size, and read/write positions.
Replace the dvb_ringbuffer_init() call in dvb_dvr_open() with direct
assignment of data/size and a call to dvb_ringbuffer_reset(), which
properly resets pread, pwrite, and error with correct memory ordering
without touching the waitqueue or spinlock.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
net: add proper RCU protection to /proc/net/ptype
Yin Fengwei reported an RCU stall in ptype_seq_show() and provided
a patch.
Real issue is that ptype_seq_next() and ptype_seq_show() violate
RCU rules.
ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev
to get device name without any barrier.
At the same time, concurrent writers can remove a packet_type structure
(which is correctly freed after an RCU grace period) and clear pt->dev
without an RCU grace period.
Define ptype_iter_state to carry a dev pointer along seq_net_private:
struct ptype_iter_state {
struct seq_net_private p;
struct net_device *dev; // added in this patch
};
We need to record the device pointer in ptype_get_idx() and
ptype_seq_next() so that ptype_seq_show() is safe against
concurrent pt->dev changes.
We also need to add full RCU protection in ptype_seq_next().
(Missing READ_ONCE() when reading list.next values)
Many thanks to Dong Chenchen for providing a repro.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
net: liquidio: Fix off-by-one error in VF setup_nic_devices() cleanup
In setup_nic_devices(), the initialization loop jumps to the label
setup_nic_dev_free on failure. The current cleanup loop while(i--)
skip the failing index i, causing a memory leak.
Fix this by changing the loop to iterate from the current index i
down to 0.
Compile tested only. Issue found using code review.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
net: liquidio: Fix off-by-one error in PF setup_nic_devices() cleanup
In setup_nic_devices(), the initialization loop jumps to the label
setup_nic_dev_free on failure. The current cleanup loop while(i--)
skip the failing index i, causing a memory leak.
Fix this by changing the loop to iterate from the current index i
down to 0.
Also, decrement i in the devlink_alloc failure path to point to the
last successfully allocated index.
Compile tested only. Issue found using code review.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not free data reservation in fallback from inline due to -ENOSPC
If we fail to create an inline extent due to -ENOSPC, we will attempt to
go through the normal COW path, reserve an extent, create an ordered
extent, etc. However we were always freeing the reserved qgroup data,
which is wrong since we will use data. Fix this by freeing the reserved
qgroup data in __cow_file_range_inline() only if we are not doing the
fallback (ret is <= 0).
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix reservation leak in some error paths when inserting inline extent
If we fail to allocate a path or join a transaction, we return from
__cow_file_range_inline() without freeing the reserved qgroup data,
resulting in a leak. Fix this by ensuring we call btrfs_qgroup_free_data()
in such cases.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-18