Linux: >> Linux Kernel >> 2.6.31.8 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: only handle RESPONSE during service challenge
Only process RESPONSE packets while the service connection is still in
RXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before
running response verification and security initialization, then use a local
secured flag to decide whether to queue the secured-connection work after
the state transition. This keeps duplicate or late RESPONSE packets from
re-running the setup path and removes the unlocked post-transition state
test.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-04-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_multiport: validate range encoding in checkentry
ports_match_v1() treats any non-zero pflags entry as the start of a
port range and unconditionally consumes the next ports[] element as
the range end.
The checkentry path currently validates protocol, flags and count, but
it does not validate the range encoding itself. As a result, malformed
rules can mark the last slot as a range start or place two range starts
back to back, leaving ports_match_v1() to step past the last valid
ports[] element while interpreting the rule.
Reject malformed multiport v1 rules in checkentry by validating that
each range start has a following element and that the following element
is not itself marked as another range start.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()
Reject rt match rules whose addrnr exceeds IP6T_RT_HOPS.
rt_mt6() expects addrnr to stay within the bounds of rtinfo->addrs[].
Validate addrnr during rule installation so malformed rules are rejected
before the match logic can use an out-of-range value.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-04-25
In the Linux kernel, the following vulnerability has been resolved:
net: rfkill: prevent unlimited numbers of rfkill events from being created
Userspace can create an unlimited number of rfkill events if the system
is so configured, while not consuming them from the rfkill file
descriptor, causing a potential out of memory situation. Prevent this
from bounding the number of pending rfkill events at a "large" number
(i.e. 1000) to prevent abuses like this.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: use netlink policy range checks
Replace manual range and mask validations with netlink policy
annotations in ctnetlink code paths, so that the netlink core rejects
invalid values early and can generate extack errors.
- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at
policy level, removing the manual >= TCP_CONNTRACK_MAX check.
- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE
(14). The normal TCP option parsing path already clamps to this value,
but the ctnetlink path accepted 0-255, causing undefined behavior when
used as a u32 shift count.
- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with
CTA_FILTER_F_ALL, removing the manual mask checks.
- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding
a new mask define grouping all valid expect flags.
Extracted from a broader nf-next patch by Florian Westphal, scoped to
ctnetlink for the fixes tree.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_expect: skip expectations in other netns via proc
Skip expectations that do not reside in this netns.
Similar to e77e6ff502ea ("netfilter: conntrack: do not dump other netns's
conntrack entries via proc").
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false
A UAF issue occurs when the virtio_net driver is configured with napi_tx=N
and the device's IFF_XMIT_DST_RELEASE flag is cleared
(e.g., during the configuration of tc route filter rules).
When IFF_XMIT_DST_RELEASE is removed from the net_device, the network stack
expects the driver to hold the reference to skb->dst until the packet
is fully transmitted and freed. In virtio_net with napi_tx=N,
skbs may remain in the virtio transmit ring for an extended period.
If the network namespace is destroyed while these skbs are still pending,
the corresponding dst_ops structure has freed. When a subsequent packet
is transmitted, free_old_xmit() is triggered to clean up old skbs.
It then calls dst_release() on the skb associated with the stale dst_entry.
Since the dst_ops (referenced by the dst_entry) has already been freed,
a UAF kernel paging request occurs.
fix it by adds skb_dst_drop(skb) in start_xmit to explicitly release
the dst reference before the skb is queued in virtio_net.
Call Trace:
Unable to handle kernel paging request at virtual address ffff80007e150000
CPU: 2 UID: 0 PID: 6236 Comm: ping Kdump: loaded Not tainted 7.0.0-rc1+ #6 PREEMPT
...
percpu_counter_add_batch+0x3c/0x158 lib/percpu_counter.c:98 (P)
dst_release+0xe0/0x110 net/core/dst.c:177
skb_release_head_state+0xe8/0x108 net/core/skbuff.c:1177
sk_skb_reason_drop+0x54/0x2d8 net/core/skbuff.c:1255
dev_kfree_skb_any_reason+0x64/0x78 net/core/dev.c:3469
napi_consume_skb+0x1c4/0x3a0 net/core/skbuff.c:1527
__free_old_xmit+0x164/0x230 drivers/net/virtio_net.c:611 [virtio_net]
free_old_xmit drivers/net/virtio_net.c:1081 [virtio_net]
start_xmit+0x7c/0x530 drivers/net/virtio_net.c:3329 [virtio_net]
...
Reproduction Steps:
NETDEV="enp3s0"
config_qdisc_route_filter() {
tc qdisc del dev $NETDEV root
tc qdisc add dev $NETDEV root handle 1: prio
tc filter add dev $NETDEV parent 1:0 \
protocol ip prio 100 route to 100 flowid 1:1
ip route add 192.168.1.100/32 dev $NETDEV realm 100
}
test_ns() {
ip netns add testns
ip link set $NETDEV netns testns
ip netns exec testns ifconfig $NETDEV 10.0.32.46/24
ip netns exec testns ping -c 1 10.0.32.1
ip netns del testns
}
config_qdisc_route_filter
test_ns
sleep 2
test_ns
CVSS Score
7.8
EPSS Score
0.001
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()
A malicious or compromised VIO server can return a num_written value in the
discover targets MAD response that exceeds max_targets. This value is
stored directly in vhost->num_targets without validation, and is then used
as the loop bound in ibmvfc_alloc_targets() to index into disc_buf[], which
is only allocated for max_targets entries. Indices at or beyond max_targets
access kernel memory outside the DMA-coherent allocation. The
out-of-bounds data is subsequently embedded in Implicit Logout and PLOGI
MADs that are sent back to the VIO server, leaking kernel memory.
Fix by clamping num_written to max_targets before storing it.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid infinite loops caused by residual data
On the mkdir/mknod path, when mapping logical blocks to physical blocks,
if inserting a new extent into the extent tree fails (in this example,
because the file system disabled the huge file feature when marking the
inode as dirty), ext4_ext_map_blocks() only calls ext4_free_blocks() to
reclaim the physical block without deleting the corresponding data in
the extent tree. This causes subsequent mkdir operations to reference
the previously reclaimed physical block number again, even though this
physical block is already being used by the xattr block. Therefore, a
situation arises where both the directory and xattr are using the same
buffer head block in memory simultaneously.
The above causes ext4_xattr_block_set() to enter an infinite loop about
"inserted" and cannot release the inode lock, ultimately leading to the
143s blocking problem mentioned in [1].
If the metadata is corrupted, then trying to remove some extent space
can do even more harm. Also in case EXT4_GET_BLOCKS_DELALLOC_RESERVE
was passed, remove space wrongly update quota information.
Jan Kara suggests distinguishing between two cases:
1) The error is ENOSPC or EDQUOT - in this case the filesystem is fully
consistent and we must maintain its consistency including all the
accounting. However these errors can happen only early before we've
inserted the extent into the extent tree. So current code works correctly
for this case.
2) Some other error - this means metadata is corrupted. We should strive to
do as few modifications as possible to limit damage. So I'd just skip
freeing of allocated blocks.
[1]
INFO: task syz.0.17:5995 blocked for more than 143 seconds.
Call Trace:
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
CVSS Score
9.4
EPSS Score
0.004
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
ext4: validate p_idx bounds in ext4_ext_correct_indexes
ext4_ext_correct_indexes() walks up the extent tree correcting
index entries when the first extent in a leaf is modified. Before
accessing path[k].p_idx->ei_block, there is no validation that
p_idx falls within the valid range of index entries for that
level.
If the on-disk extent header contains a corrupted or crafted
eh_entries value, p_idx can point past the end of the allocated
buffer, causing a slab-out-of-bounds read.
Fix this by validating path[k].p_idx against EXT_LAST_INDEX() at
both access sites: before the while loop and inside it. Return
-EFSCORRUPTED if the index pointer is out of range, consistent
with how other bounds violations are handled in the ext4 extent
tree code.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-04-22