Linux: >> Linux Kernel >> 2.6.12.5 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
atm: lec: fix null-ptr-deref in lec_arp_clear_vccs
syzkaller reported a null-ptr-deref in lec_arp_clear_vccs().
This issue can be easily reproduced using the syzkaller reproducer.
In the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by
multiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).
When the underlying VCC is closed, lec_vcc_close() iterates over all
ARP entries and calls lec_arp_clear_vccs() for each matched entry.
For example, when lec_vcc_close() iterates through the hlists in
priv->lec_arp_empty_ones or other ARP tables:
1. In the first iteration, for the first matched ARP entry sharing the VCC,
lec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)
and sets vcc->user_back to NULL.
2. In the second iteration, for the next matched ARP entry sharing the same
VCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from
vcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it
via `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.
Fix this by adding a null check for vpriv before dereferencing
it. If vpriv is already NULL, it means the VCC has been cleared
by a previous call, so we can safely skip the cleanup and just
clear the entry's vcc/recv_vcc pointers.
The entire cleanup block (including vcc_release_async()) is placed inside
the vpriv guard because a NULL vpriv indicates the VCC has already been
fully released by a prior iteration — repeating the teardown would
redundantly set flags and trigger callbacks on an already-closing socket.
The Fixes tag points to the initial commit because the entry->vcc path has
been vulnerable since the original code. The entry->recv_vcc path was later
added by commit 8d9f73c0ad2f ("atm: fix a memory leak of vcc->user_back")
with the same pattern, and both paths are fixed here.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
fbdev: rivafb: fix divide error in nv3_arb()
A userspace program can trigger the RIVA NV3 arbitration code by calling
the FBIOPUT_VSCREENINFO ioctl on /dev/fb*. When doing so, the driver
recomputes FIFO arbitration parameters in nv3_arb(), using state->mclk_khz
(derived from the PRAMDAC MCLK PLL) as a divisor without validating it
first.
In a normal setup, state->mclk_khz is provided by the real hardware and is
non-zero. However, an attacker can construct a malicious or misconfigured
device (e.g. a crafted/emulated PCI device) that exposes a bogus PLL
configuration, causing state->mclk_khz to become zero. Once
nv3_get_param() calls nv3_arb(), the division by state->mclk_khz in the gns
calculation causes a divide error and crashes the kernel.
Fix this by checking whether state->mclk_khz is zero and bailing out before
doing the division.
The following log reveals it:
rivafb: setting virtual Y resolution to 2184
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 PID: 2187 Comm: syz-executor.0 Not tainted 5.18.0-rc1+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:nv3_arb drivers/video/fbdev/riva/riva_hw.c:439 [inline]
RIP: 0010:nv3_get_param+0x3ab/0x13b0 drivers/video/fbdev/riva/riva_hw.c:546
Call Trace:
nv3CalcArbitration.constprop.0+0x255/0x460 drivers/video/fbdev/riva/riva_hw.c:603
nv3UpdateArbitrationSettings drivers/video/fbdev/riva/riva_hw.c:637 [inline]
CalcStateExt+0x447/0x1b90 drivers/video/fbdev/riva/riva_hw.c:1246
riva_load_video_mode+0x8a9/0xea0 drivers/video/fbdev/riva/fbdev.c:779
rivafb_set_par+0xc0/0x5f0 drivers/video/fbdev/riva/fbdev.c:1196
fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1033
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1109
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1188
__x64_sys_ioctl+0x122/0x190 fs/ioctl.c:856
CVSS Score
5.5
EPSS Score
0.001
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
0.001
Published
2026-03-18
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
0.002
Published
2026-03-04
Vulnerability in Centreon Centreon Open Tickets on Central Server on Linux (Centroen Open Ticket modules).This issue affects Centreon Open Tickets on Central Server: from all before 25.10.3, 24.10.8, 24.04.7.
CVSS Score
9.9
EPSS Score
0.005
Published
2026-02-27
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
0.006
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
0.006
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
0.004
Published
2026-02-20
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
8.8
EPSS Score
0.002
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
0.001
Published
2026-02-04