Linux: >> Linux Kernel >> 3.15.1 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: do not free existing class in qfq_change_class()
Fixes qfq_change_class() error case.
cl->qdisc and cl should only be freed if a new class and qdisc
were allocated, or we risk various UAF.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
libceph: replace overzealous BUG_ON in osdmap_apply_incremental()
If the osdmap is (maliciously) corrupted such that the incremental
osdmap epoch is different from what is expected, there is no need to
BUG. Instead, just declare the incremental osdmap to be invalid.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
wifi: avoid kernel-infoleak from struct iw_point
struct iw_point has a 32bit hole on 64bit arches.
struct iw_point {
void __user *pointer; /* Pointer to the data (in user space) */
__u16 length; /* number of fields or size in bytes */
__u16 flags; /* Optional params */
};
Make sure to zero the structure to avoid disclosing 32bits of kernel data
to user space.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
net: usb: rtl8150: fix memory leak on usb_submit_urb() failure
In async_set_registers(), when usb_submit_urb() fails, the allocated
async_req structure and URB are not freed, causing a memory leak.
The completion callback async_set_reg_cb() is responsible for freeing
these allocations, but it is only called after the URB is successfully
submitted and completes (successfully or with error). If submission
fails, the callback never runs and the memory is leaked.
Fix this by freeing both the URB and the request structure in the error
path when usb_submit_urb() fails.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset
`qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class
itself is active.
Two qfq_class objects may point to the same leaf_qdisc. This happens
when:
1. one QFQ qdisc is attached to the dev as the root qdisc, and
2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()
/ qdisc_put()) and is pending to be destroyed, as in function
tc_new_tfilter.
When packets are enqueued through the root QFQ qdisc, the shared
leaf_qdisc->q.qlen increases. At the same time, the second QFQ
qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters
qfq_reset() with its own q->q.qlen == 0, but its class's leaf
qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate
an inactive aggregate and trigger a null-deref in qfq_deactivate_agg:
[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 0.903571] #PF: supervisor write access in kernel mode
[ 0.903860] #PF: error_code(0x0002) - not-present page
[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0
[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI
[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE
[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0
Code starting with the faulting instruction
===========================================
0: 0f 84 4d 01 00 00 je 0x153
6: 48 89 70 18 mov %rsi,0x18(%rax)
a: 8b 4b 10 mov 0x10(%rbx),%ecx
d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx
14: 48 8b 78 08 mov 0x8(%rax),%rdi
18: 48 d3 e2 shl %cl,%rdx
1b: 48 21 f2 and %rsi,%rdx
1e: 48 2b 13 sub (%rbx),%rdx
21: 48 8b 30 mov (%rax),%rsi
24: 48 d3 ea shr %cl,%rdx
27: 8b 4b 18 mov 0x18(%rbx),%ecx
...
[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[ 0.910247] PKRU: 55555554
[ 0.910391] Call Trace:
[ 0.910527] <TASK>
[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)
[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)
[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)
[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)
[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)
[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)
[ 0.912484] netlink_sendmsg (net/netlink/af
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-21
In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential null-ptr-deref in device_add()
I got the following null-ptr-deref report while doing fault injection test:
BUG: kernel NULL pointer dereference, address: 0000000000000058
CPU: 2 PID: 278 Comm: 37-i2c-ds2482 Tainted: G B W N 6.1.0-rc3+
RIP: 0010:klist_put+0x2d/0xd0
Call Trace:
<TASK>
klist_remove+0xf1/0x1c0
device_release_driver_internal+0x196/0x210
bus_remove_device+0x1bd/0x240
device_add+0xd3d/0x1100
w1_add_master_device+0x476/0x490 [wire]
ds2482_probe+0x303/0x3e0 [ds2482]
This is how it happened:
w1_alloc_dev()
// The dev->driver is set to w1_master_driver.
memcpy(&dev->dev, device, sizeof(struct device));
device_add()
bus_add_device()
dpm_sysfs_add() // It fails, calls bus_remove_device.
// error path
bus_remove_device()
// The dev->driver is not null, but driver is not bound.
__device_release_driver()
klist_remove(&dev->p->knode_driver) <-- It causes null-ptr-deref.
// normal path
bus_probe_device() // It's not called yet.
device_bind_driver()
If dev->driver is set, in the error path after calling bus_add_device()
in device_add(), bus_remove_device() is called, then the device will be
detached from driver. But device_bind_driver() is not called yet, so it
causes null-ptr-deref while access the 'knode_driver'. To fix this, set
dev->driver to null in the error path before calling bus_remove_device().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-12-30
In the Linux kernel, the following vulnerability has been resolved:
team: Move team device type change at the end of team_port_add
Attempting to add a port device that is already up will expectedly fail,
but not before modifying the team device header_ops.
In the case of the syzbot reproducer the gre0 device is
already in state UP when it attempts to add it as a
port device of team0, this fails but before that
header_ops->create of team0 is changed from eth_header to ipgre_header
in the call to team_dev_type_check_change.
Later when we end up in ipgre_header() struct ip_tunnel* points to nonsense
as the private data of the device still holds a struct team.
Example sequence of iproute2 commands to reproduce the hang/BUG():
ip link add dev team0 type team
ip link add dev gre0 type gre
ip link set dev gre0 up
ip link set dev gre0 master team0
ip link set dev team0 up
ping -I team0 1.1.1.1
Move team_dev_type_check_change down where all other checks have passed
as it changes the dev type with no way to restore it in case
one of the checks that follow it fail.
Also make sure to preserve the origial mtu assignment:
- If port_dev is not the same type as dev, dev takes mtu from port_dev
- If port_dev is the same type as dev, port_dev takes mtu from dev
This is done by adding a conditional before the call to dev_set_mtu
to prevent it from assigning port_dev->mtu = dev->mtu and instead
letting team_dev_type_check_change assign dev->mtu = port_dev->mtu.
The conditional is needed because the patch moves the call to
team_dev_type_check_change past dev_set_mtu.
Testing:
- team device driver in-tree selftests
- Add/remove various devices as slaves of team device
- syzbot
CVSS Score
5.5
EPSS Score
0.0
Published
2025-12-23
In the Linux kernel, the following vulnerability has been resolved:
ksm: use range-walk function to jump over holes in scan_get_next_rmap_item
Currently, scan_get_next_rmap_item() walks every page address in a VMA to
locate mergeable pages. This becomes highly inefficient when scanning
large virtual memory areas that contain mostly unmapped regions, causing
ksmd to use large amount of cpu without deduplicating much pages.
This patch replaces the per-address lookup with a range walk using
walk_page_range(). The range walker allows KSM to skip over entire
unmapped holes in a VMA, avoiding unnecessary lookups. This problem was
previously discussed in [1].
Consider the following test program which creates a 32 TiB mapping in the
virtual address space but only populates a single page:
#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
/* 32 TiB */
const size_t size = 32ul * 1024 * 1024 * 1024 * 1024;
int main() {
char *area = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0);
if (area == MAP_FAILED) {
perror("mmap() failed\n");
return -1;
}
/* Populate a single page such that we get an anon_vma. */
*area = 0;
/* Enable KSM. */
madvise(area, size, MADV_MERGEABLE);
pause();
return 0;
}
$ ./ksm-sparse &
$ echo 1 > /sys/kernel/mm/ksm/run
Without this patch ksmd uses 100% of the cpu for a long time (more then 1
hour in my test machine) scanning all the 32 TiB virtual address space
that contain only one mapped page. This makes ksmd essentially deadlocked
not able to deduplicate anything of value. With this patch ksmd walks
only the one mapped page and skips the rest of the 32 TiB virtual address
space, making the scan fast using little cpu.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-12-16
In the Linux kernel, the following vulnerability has been resolved:
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Issuing two writes to the same af_alg socket is bogus as the
data will be interleaved in an unpredictable fashion. Furthermore,
concurrent writes may create inconsistencies in the internal
socket state.
Disallow this by adding a new ctx->write field that indiciates
exclusive ownership for writing.
CVSS Score
3.3
EPSS Score
0.0
Published
2025-10-13
In the Linux kernel, the following vulnerability has been resolved:
tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().
syzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk
in the TCP_ESTABLISHED state. [0]
syzbot reused the server-side TCP Fast Open socket as a new client before
the TFO socket completes 3WHS:
1. accept()
2. connect(AF_UNSPEC)
3. connect() to another destination
As of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes
it to TCP_CLOSE and makes connect() possible, which restarts timers.
Since tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the
retransmit timer triggered the warning and the intended packet was not
retransmitted.
Let's call reqsk_fastopen_remove() in tcp_disconnect().
[0]:
WARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))
Modules linked in:
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))
Code: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e
RSP: 0018:ffffc900002f8d40 EFLAGS: 00010293
RAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017
RDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400
RBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8
R10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540
R13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0
FS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0
Call Trace:
<IRQ>
tcp_write_timer (net/ipv4/tcp_timer.c:738)
call_timer_fn (kernel/time/timer.c:1747)
__run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372)
timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135)
tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035)
__walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1))
tmigr_handle_remote (kernel/time/timer_migration.c:1096)
handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580)
irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35))
</IRQ>
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-09
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