Linux: >> Linux Kernel >> 2.6.26.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
romfs: check sb_set_blocksize() return value
romfs_fill_super() ignores the return value of sb_set_blocksize(), which
can fail if the requested block size is incompatible with the block
device's configuration.
This can be triggered by setting a loop device's block size larger than
PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs
filesystem on that device.
When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the
device has logical_block_size=32768, bdev_validate_blocksize() fails
because the requested size is smaller than the device's logical block
size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and
continues mounting.
The superblock's block size remains at the device's logical block size
(32768). Later, when sb_bread() attempts I/O with this oversized block
size, it triggers a kernel BUG in folio_set_bh():
kernel BUG at fs/buffer.c:1582!
BUG_ON(size > PAGE_SIZE);
Fix by checking the return value of sb_set_blocksize() and failing the
mount with -EINVAL if it returns 0.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-04
Sensitive data disclosure and manipulation due to improper authentication. The following products are affected: Acronis Cyber Protect 16 (Linux, Windows) before build 39938, Acronis Cyber Protect 15 (Linux, Windows) before build 41800.
CVSS Score
10.0
EPSS Score
0.0
Published
2026-02-20
Sensitive data disclosure and manipulation due to improper authentication. The following products are affected: Acronis Cyber Protect 16 (Linux, Windows) before build 39938, Acronis Cyber Protect 15 (Linux, Windows) before build 41800.
CVSS Score
10.0
EPSS Score
0.0
Published
2026-02-20
Sensitive data disclosure and manipulation due to missing authorization. The following products are affected: Acronis Cyber Protect 16 (Linux, Windows) before build 39938, Acronis Cyber Protect 15 (Linux, Windows) before build 41800.
CVSS Score
10.0
EPSS Score
0.0
Published
2026-02-20
In the Linux kernel, the following vulnerability has been resolved:
bonding: annotate data-races around slave->last_rx
slave->last_rx and slave->target_last_arp_rx[...] can be read and written
locklessly. Add READ_ONCE() and WRITE_ONCE() annotations.
syzbot reported:
BUG: KCSAN: data-race in bond_rcv_validate / bond_rcv_validate
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 1:
bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335
bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533
__netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039
__netif_receive_skb_one_core net/core/dev.c:6150 [inline]
__netif_receive_skb+0x59/0x270 net/core/dev.c:6265
netif_receive_skb_internal net/core/dev.c:6351 [inline]
netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410
...
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 0:
bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335
bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533
__netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039
__netif_receive_skb_one_core net/core/dev.c:6150 [inline]
__netif_receive_skb+0x59/0x270 net/core/dev.c:6265
netif_receive_skb_internal net/core/dev.c:6351 [inline]
netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410
br_netif_receive_skb net/bridge/br_input.c:30 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
...
value changed: 0x0000000100005365 -> 0x0000000100005366
CVSS Score
4.7
EPSS Score
0.0
Published
2026-02-18
In the Linux kernel, the following vulnerability has been resolved:
sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT
A null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key
initialization fails:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2
RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline]
RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401
Call Trace:
sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189
sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111
sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217
sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787
sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169
sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052
sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88
sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243
sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127
The issue is triggered when sctp_auth_asoc_init_active_key() fails in
sctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the
command sequence is currently:
- SCTP_CMD_PEER_INIT
- SCTP_CMD_TIMER_STOP (T1_INIT)
- SCTP_CMD_TIMER_START (T1_COOKIE)
- SCTP_CMD_NEW_STATE (COOKIE_ECHOED)
- SCTP_CMD_ASSOC_SHKEY
- SCTP_CMD_GEN_COOKIE_ECHO
If SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while
asoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by
SCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL
to be queued by sctp_datamsg_from_user().
Since command interpretation stops on failure, no COOKIE_ECHO should been
sent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already
been started, and it may enqueue a COOKIE_ECHO into the outqueue later. As
a result, the DATA chunk can be transmitted together with the COOKIE_ECHO
in sctp_outq_flush_data(), leading to the observed issue.
Similar to the other places where it calls sctp_auth_asoc_init_active_key()
right after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY
immediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting
T1_COOKIE. This ensures that if shared key generation fails, authenticated
DATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT,
giving the client another chance to process INIT_ACK and retry key setup.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
netrom: fix double-free in nr_route_frame()
In nr_route_frame(), old_skb is immediately freed without checking if
nr_neigh->ax25 pointer is NULL. Therefore, if nr_neigh->ax25 is NULL,
the caller function will free old_skb again, causing a double-free bug.
Therefore, to prevent this, we need to modify it to check whether
nr_neigh->ax25 is NULL before freeing old_skb.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
bonding: limit BOND_MODE_8023AD to Ethernet devices
BOND_MODE_8023AD makes sense for ARPHRD_ETHER only.
syzbot reported:
BUG: KASAN: global-out-of-bounds in __hw_addr_create net/core/dev_addr_lists.c:63 [inline]
BUG: KASAN: global-out-of-bounds in __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118
Read of size 16 at addr ffffffff8bf94040 by task syz.1.3580/19497
CPU: 1 UID: 0 PID: 19497 Comm: syz.1.3580 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
__asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
__hw_addr_create net/core/dev_addr_lists.c:63 [inline]
__hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118
__dev_mc_add net/core/dev_addr_lists.c:868 [inline]
dev_mc_add+0xa1/0x120 net/core/dev_addr_lists.c:886
bond_enslave+0x2b8b/0x3ac0 drivers/net/bonding/bond_main.c:2180
do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963
do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165
rtnl_changelink net/core/rtnetlink.c:3776 [inline]
__rtnl_newlink net/core/rtnetlink.c:3935 [inline]
rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x820 net/socket.c:2592
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
__sys_sendmsg+0x164/0x220 net/socket.c:2678
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x1dc/0x560 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
</TASK>
The buggy address belongs to the variable:
lacpdu_mcast_addr+0x0/0x40
CVSS Score
7.1
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix use-after-free in snd_usb_mixer_free()
When snd_usb_create_mixer() fails, snd_usb_mixer_free() frees
mixer->id_elems but the controls already added to the card still
reference the freed memory. Later when snd_card_register() runs,
the OSS mixer layer calls their callbacks and hits a use-after-free read.
Call trace:
get_ctl_value+0x63f/0x820 sound/usb/mixer.c:411
get_min_max_with_quirks.isra.0+0x240/0x1f40 sound/usb/mixer.c:1241
mixer_ctl_feature_info+0x26b/0x490 sound/usb/mixer.c:1381
snd_mixer_oss_build_test+0x174/0x3a0 sound/core/oss/mixer_oss.c:887
...
snd_card_register+0x4ed/0x6d0 sound/core/init.c:923
usb_audio_probe+0x5ef/0x2a90 sound/usb/card.c:1025
Fix by calling snd_ctl_remove() for all mixer controls before freeing
id_elems. We save the next pointer first because snd_ctl_remove()
frees the current element.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Enforce that teql can only be used as root qdisc
Design intent of teql is that it is only supposed to be used as root qdisc.
We need to check for that constraint.
Although not important, I will describe the scenario that unearthed this
issue for the curious.
GangMin Kim <km.kim1503@gmail.com> managed to concot a scenario as follows:
ROOT qdisc 1:0 (QFQ)
├── class 1:1 (weight=15, lmax=16384) netem with delay 6.4s
└── class 1:2 (weight=1, lmax=1514) teql
GangMin sends a packet which is enqueued to 1:1 (netem).
Any invocation of dequeue by QFQ from this class will not return a packet
until after 6.4s. In the meantime, a second packet is sent and it lands on
1:2. teql's enqueue will return success and this will activate class 1:2.
Main issue is that teql only updates the parent visible qlen (sch->q.qlen)
at dequeue. Since QFQ will only call dequeue if peek succeeds (and teql's
peek always returns NULL), dequeue will never be called and thus the qlen
will remain as 0. With that in mind, when GangMin updates 1:2's lmax value,
the qfq_change_class calls qfq_deact_rm_from_agg. Since the child qdisc's
qlen was not incremented, qfq fails to deactivate the class, but still
frees its pointers from the aggregate. So when the first packet is
rescheduled after 6.4 seconds (netem's delay), a dangling pointer is
accessed causing GangMin's causing a UAF.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-02-04
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