Linux: >> Linux Kernel >> 6.0.18 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: sched: fix memory leak in tcindex_set_parms
Syzkaller reports a memory leak as follows:
====================================
BUG: memory leak
unreferenced object 0xffff88810c287f00 (size 256):
comm "syz-executor105", pid 3600, jiffies 4294943292 (age 12.990s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814cf9f0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046
[<ffffffff839c9e07>] kmalloc include/linux/slab.h:576 [inline]
[<ffffffff839c9e07>] kmalloc_array include/linux/slab.h:627 [inline]
[<ffffffff839c9e07>] kcalloc include/linux/slab.h:659 [inline]
[<ffffffff839c9e07>] tcf_exts_init include/net/pkt_cls.h:250 [inline]
[<ffffffff839c9e07>] tcindex_set_parms+0xa7/0xbe0 net/sched/cls_tcindex.c:342
[<ffffffff839caa1f>] tcindex_change+0xdf/0x120 net/sched/cls_tcindex.c:553
[<ffffffff8394db62>] tc_new_tfilter+0x4f2/0x1100 net/sched/cls_api.c:2147
[<ffffffff8389e91c>] rtnetlink_rcv_msg+0x4dc/0x5d0 net/core/rtnetlink.c:6082
[<ffffffff839eba67>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2540
[<ffffffff839eab87>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
[<ffffffff839eab87>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345
[<ffffffff839eb046>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921
[<ffffffff8383e796>] sock_sendmsg_nosec net/socket.c:714 [inline]
[<ffffffff8383e796>] sock_sendmsg+0x56/0x80 net/socket.c:734
[<ffffffff8383eb08>] ____sys_sendmsg+0x178/0x410 net/socket.c:2482
[<ffffffff83843678>] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536
[<ffffffff838439c5>] __sys_sendmmsg+0x105/0x330 net/socket.c:2622
[<ffffffff83843c14>] __do_sys_sendmmsg net/socket.c:2651 [inline]
[<ffffffff83843c14>] __se_sys_sendmmsg net/socket.c:2648 [inline]
[<ffffffff83843c14>] __x64_sys_sendmmsg+0x24/0x30 net/socket.c:2648
[<ffffffff84605fd5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84605fd5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
====================================
Kernel uses tcindex_change() to change an existing
filter properties.
Yet the problem is that, during the process of changing,
if `old_r` is retrieved from `p->perfect`, then
kernel uses tcindex_alloc_perfect_hash() to newly
allocate filter results, uses tcindex_filter_result_init()
to clear the old filter result, without destroying
its tcf_exts structure, which triggers the above memory leak.
To be more specific, there are only two source for the `old_r`,
according to the tcindex_lookup(). `old_r` is retrieved from
`p->perfect`, or `old_r` is retrieved from `p->h`.
* If `old_r` is retrieved from `p->perfect`, kernel uses
tcindex_alloc_perfect_hash() to newly allocate the
filter results. Then `r` is assigned with `cp->perfect + handle`,
which is newly allocated. So condition `old_r && old_r != r` is
true in this situation, and kernel uses tcindex_filter_result_init()
to clear the old filter result, without destroying
its tcf_exts structure
* If `old_r` is retrieved from `p->h`, then `p->perfect` is NULL
according to the tcindex_lookup(). Considering that `cp->h`
is directly copied from `p->h` and `p->perfect` is NULL,
`r` is assigned with `tcindex_lookup(cp, handle)`, whose value
should be the same as `old_r`, so condition `old_r && old_r != r`
is false in this situation, kernel ignores using
tcindex_filter_result_init() to clear the old filter result.
So only when `old_r` is retrieved from `p->perfect` does kernel use
tcindex_filter_result_init() to clear the old filter result, which
triggers the above memory leak.
Considering that there already exists a tc_filter_wq workqueue
to destroy the old tcindex_d
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
nvme: fix multipath crash caused by flush request when blktrace is enabled
The flush request initialized by blk_kick_flush has NULL bio,
and it may be dealt with nvme_end_req during io completion.
When blktrace is enabled, nvme_trace_bio_complete with multipath
activated trying to access NULL pointer bio from flush request
results in the following crash:
[ 2517.831677] BUG: kernel NULL pointer dereference, address: 000000000000001a
[ 2517.835213] #PF: supervisor read access in kernel mode
[ 2517.838724] #PF: error_code(0x0000) - not-present page
[ 2517.842222] PGD 7b2d51067 P4D 0
[ 2517.845684] Oops: 0000 [#1] SMP NOPTI
[ 2517.849125] CPU: 2 PID: 732 Comm: kworker/2:1H Kdump: loaded Tainted: G S 5.15.67-0.cl9.x86_64 #1
[ 2517.852723] Hardware name: XFUSION 2288H V6/BC13MBSBC, BIOS 1.13 07/27/2022
[ 2517.856358] Workqueue: nvme_tcp_wq nvme_tcp_io_work [nvme_tcp]
[ 2517.859993] RIP: 0010:blk_add_trace_bio_complete+0x6/0x30
[ 2517.863628] Code: 1f 44 00 00 48 8b 46 08 31 c9 ba 04 00 10 00 48 8b 80 50 03 00 00 48 8b 78 50 e9 e5 fe ff ff 0f 1f 44 00 00 41 54 49 89 f4 55 <0f> b6 7a 1a 48 89 d5 e8 3e 1c 2b 00 48 89 ee 4c 89 e7 5d 89 c1 ba
[ 2517.871269] RSP: 0018:ff7f6a008d9dbcd0 EFLAGS: 00010286
[ 2517.875081] RAX: ff3d5b4be00b1d50 RBX: 0000000002040002 RCX: ff3d5b0a270f2000
[ 2517.878966] RDX: 0000000000000000 RSI: ff3d5b0b021fb9f8 RDI: 0000000000000000
[ 2517.882849] RBP: ff3d5b0b96a6fa00 R08: 0000000000000001 R09: 0000000000000000
[ 2517.886718] R10: 000000000000000c R11: 000000000000000c R12: ff3d5b0b021fb9f8
[ 2517.890575] R13: 0000000002000000 R14: ff3d5b0b021fb1b0 R15: 0000000000000018
[ 2517.894434] FS: 0000000000000000(0000) GS:ff3d5b42bfc80000(0000) knlGS:0000000000000000
[ 2517.898299] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2517.902157] CR2: 000000000000001a CR3: 00000004f023e005 CR4: 0000000000771ee0
[ 2517.906053] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2517.909930] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2517.913761] PKRU: 55555554
[ 2517.917558] Call Trace:
[ 2517.921294] <TASK>
[ 2517.924982] nvme_complete_rq+0x1c3/0x1e0 [nvme_core]
[ 2517.928715] nvme_tcp_recv_pdu+0x4d7/0x540 [nvme_tcp]
[ 2517.932442] nvme_tcp_recv_skb+0x4f/0x240 [nvme_tcp]
[ 2517.936137] ? nvme_tcp_recv_pdu+0x540/0x540 [nvme_tcp]
[ 2517.939830] tcp_read_sock+0x9c/0x260
[ 2517.943486] nvme_tcp_try_recv+0x65/0xa0 [nvme_tcp]
[ 2517.947173] nvme_tcp_io_work+0x64/0x90 [nvme_tcp]
[ 2517.950834] process_one_work+0x1e8/0x390
[ 2517.954473] worker_thread+0x53/0x3c0
[ 2517.958069] ? process_one_work+0x390/0x390
[ 2517.961655] kthread+0x10c/0x130
[ 2517.965211] ? set_kthread_struct+0x40/0x40
[ 2517.968760] ret_from_fork+0x1f/0x30
[ 2517.972285] </TASK>
To avoid this situation, add a NULL check for req->bio before
calling trace_block_bio_complete.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
accel/habanalabs: fix mem leak in capture user mappings
This commit fixes a memory leak caused when clearing the user_mappings
info when a new context is opened immediately after user_mapping is
captured and a hard reset is performed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix race issue between cpu buffer write and swap
Warning happened in rb_end_commit() at code:
if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)))
WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142
rb_commit+0x402/0x4a0
Call Trace:
ring_buffer_unlock_commit+0x42/0x250
trace_buffer_unlock_commit_regs+0x3b/0x250
trace_event_buffer_commit+0xe5/0x440
trace_event_buffer_reserve+0x11c/0x150
trace_event_raw_event_sched_switch+0x23c/0x2c0
__traceiter_sched_switch+0x59/0x80
__schedule+0x72b/0x1580
schedule+0x92/0x120
worker_thread+0xa0/0x6f0
It is because the race between writing event into cpu buffer and swapping
cpu buffer through file per_cpu/cpu0/snapshot:
Write on CPU 0 Swap buffer by per_cpu/cpu0/snapshot on CPU 1
-------- --------
tracing_snapshot_write()
[...]
ring_buffer_lock_reserve()
cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a';
[...]
rb_reserve_next_event()
[...]
ring_buffer_swap_cpu()
if (local_read(&cpu_buffer_a->committing))
goto out_dec;
if (local_read(&cpu_buffer_b->committing))
goto out_dec;
buffer_a->buffers[cpu] = cpu_buffer_b;
buffer_b->buffers[cpu] = cpu_buffer_a;
// 2. cpu_buffer has swapped here.
rb_start_commit(cpu_buffer);
if (unlikely(READ_ONCE(cpu_buffer->buffer)
!= buffer)) { // 3. This check passed due to 'cpu_buffer->buffer'
[...] // has not changed here.
return NULL;
}
cpu_buffer_b->buffer = buffer_a;
cpu_buffer_a->buffer = buffer_b;
[...]
// 4. Reserve event from 'cpu_buffer_a'.
ring_buffer_unlock_commit()
[...]
cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!!
rb_commit(cpu_buffer)
rb_end_commit() // 6. WARN for the wrong 'committing' state !!!
Based on above analysis, we can easily reproduce by following testcase:
``` bash
#!/bin/bash
dmesg -n 7
sysctl -w kernel.panic_on_warn=1
TR=/sys/kernel/tracing
echo 7 > ${TR}/buffer_size_kb
echo "sched:sched_switch" > ${TR}/set_event
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
```
To fix it, IIUC, we can use smp_call_function_single() to do the swap on
the target cpu where the buffer is located, so that above race would be
avoided.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
USB: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: mm: Add p?d_leaf() definitions
When I do LTP test, LTP test case ksm06 caused panic at
break_ksm_pmd_entry
-> pmd_leaf (Huge page table but False)
-> pte_present (panic)
The reason is pmd_leaf() is not defined, So like commit 501b81046701
("mips: mm: add p?d_leaf() definitions") add p?d_leaf() definition for
LoongArch.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
ip6mr: Fix skb_under_panic in ip6mr_cache_report()
skbuff: skb_under_panic: text:ffffffff88771f69 len:56 put:-4
head:ffff88805f86a800 data:ffff887f5f86a850 tail:0x88 end:0x2c0 dev:pim6reg
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:192!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 2 PID: 22968 Comm: kworker/2:11 Not tainted 6.5.0-rc3-00044-g0a8db05b571a #236
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x152/0x1d0
Call Trace:
<TASK>
skb_push+0xc4/0xe0
ip6mr_cache_report+0xd69/0x19b0
reg_vif_xmit+0x406/0x690
dev_hard_start_xmit+0x17e/0x6e0
__dev_queue_xmit+0x2d6a/0x3d20
vlan_dev_hard_start_xmit+0x3ab/0x5c0
dev_hard_start_xmit+0x17e/0x6e0
__dev_queue_xmit+0x2d6a/0x3d20
neigh_connected_output+0x3ed/0x570
ip6_finish_output2+0x5b5/0x1950
ip6_finish_output+0x693/0x11c0
ip6_output+0x24b/0x880
NF_HOOK.constprop.0+0xfd/0x530
ndisc_send_skb+0x9db/0x1400
ndisc_send_rs+0x12a/0x6c0
addrconf_dad_completed+0x3c9/0xea0
addrconf_dad_work+0x849/0x1420
process_one_work+0xa22/0x16e0
worker_thread+0x679/0x10c0
ret_from_fork+0x28/0x60
ret_from_fork_asm+0x11/0x20
When setup a vlan device on dev pim6reg, DAD ns packet may sent on reg_vif_xmit().
reg_vif_xmit()
ip6mr_cache_report()
skb_push(skb, -skb_network_offset(pkt));//skb_network_offset(pkt) is 4
And skb_push declared as:
void *skb_push(struct sk_buff *skb, unsigned int len);
skb->data -= len;
//0xffff88805f86a84c - 0xfffffffc = 0xffff887f5f86a850
skb->data is set to 0xffff887f5f86a850, which is invalid mem addr, lead to skb_push() fails.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
block: be a bit more careful in checking for NULL bdev while polling
Wei reports a crash with an application using polled IO:
PGD 14265e067 P4D 14265e067 PUD 47ec50067 PMD 0
Oops: 0000 [#1] SMP
CPU: 0 PID: 21915 Comm: iocore_0 Kdump: loaded Tainted: G S 5.12.0-0_fbk12_clang_7346_g1bb6f2e7058f #1
Hardware name: Wiwynn Delta Lake MP T8/Delta Lake-Class2, BIOS Y3DLM08 04/10/2022
RIP: 0010:bio_poll+0x25/0x200
Code: 0f 1f 44 00 00 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 28 65 48 8b 04 25 28 00 00 00 48 89 44 24 20 48 8b 47 08 <48> 8b 80 70 02 00 00 4c 8b 70 50 8b 6f 34 31 db 83 fd ff 75 25 65
RSP: 0018:ffffc90005fafdf8 EFLAGS: 00010292
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 74b43cd65dd66600
RDX: 0000000000000003 RSI: ffffc90005fafe78 RDI: ffff8884b614e140
RBP: ffff88849964df78 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88849964df00
R13: ffffc90005fafe78 R14: ffff888137d3c378 R15: 0000000000000001
FS: 00007fd195000640(0000) GS:ffff88903f400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000270 CR3: 0000000466121001 CR4: 00000000007706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
iocb_bio_iopoll+0x1d/0x30
io_do_iopoll+0xac/0x250
__se_sys_io_uring_enter+0x3c5/0x5a0
? __x64_sys_write+0x89/0xd0
do_syscall_64+0x2d/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x94f225d
Code: 24 cc 00 00 00 41 8b 84 24 d0 00 00 00 c1 e0 04 83 e0 10 41 09 c2 8b 33 8b 53 04 4c 8b 43 18 4c 63 4b 0c b8 aa 01 00 00 0f 05 <85> c0 0f 88 85 00 00 00 29 03 45 84 f6 0f 84 88 00 00 00 41 f6 c7
RSP: 002b:00007fd194ffcd88 EFLAGS: 00000202 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fd194ffcdc0 RCX: 00000000094f225d
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007fd194ffcdb0 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000001 R11: 0000000000000202 R12: 00007fd269d68030
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
which is due to bio->bi_bdev being NULL. This can happen if we have two
tasks doing polled IO, and task B ends up completing IO from task A if
they are sharing a poll queue. If task B completes the IO and puts the
bio into our cache, then it can allocate that bio again before task A
is done polling for it. As that would necessitate a preempt between the
two tasks, it's enough to just be a bit more careful in checking for
whether or not bio->bi_bdev is NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
accel/habanalabs: postpone mem_mgr IDR destruction to hpriv_release()
The memory manager IDR is currently destroyed when user releases the
file descriptor.
However, at this point the user context might be still held, and memory
buffers might be still in use.
Later on, calls to release those buffers will fail due to not finding
their handles in the IDR, leading to a memory leak.
To avoid this leak, split the IDR destruction from the memory manager
fini, and postpone it to hpriv_release() when there is no user context
and no buffers are used.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17
In the Linux kernel, the following vulnerability has been resolved:
skbuff: skb_segment, Call zero copy functions before using skbuff frags
Commit bf5c25d60861 ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.
[ 193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[ 193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G O 5.15.123+ #26
[ 193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[ 194.021892] Call Trace:
[ 194.027422] <TASK>
[ 194.072861] tcp_gso_segment+0x107/0x540
[ 194.082031] inet_gso_segment+0x15c/0x3d0
[ 194.090783] skb_mac_gso_segment+0x9f/0x110
[ 194.095016] __skb_gso_segment+0xc1/0x190
[ 194.103131] netem_enqueue+0x290/0xb10 [sch_netem]
[ 194.107071] dev_qdisc_enqueue+0x16/0x70
[ 194.110884] __dev_queue_xmit+0x63b/0xb30
[ 194.121670] bond_start_xmit+0x159/0x380 [bonding]
[ 194.128506] dev_hard_start_xmit+0xc3/0x1e0
[ 194.131787] __dev_queue_xmit+0x8a0/0xb30
[ 194.138225] macvlan_start_xmit+0x4f/0x100 [macvlan]
[ 194.141477] dev_hard_start_xmit+0xc3/0x1e0
[ 194.144622] sch_direct_xmit+0xe3/0x280
[ 194.147748] __dev_queue_xmit+0x54a/0xb30
[ 194.154131] tap_get_user+0x2a8/0x9c0 [tap]
[ 194.157358] tap_sendmsg+0x52/0x8e0 [tap]
[ 194.167049] handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[ 194.173631] handle_tx+0xcd/0xe0 [vhost_net]
[ 194.176959] vhost_worker+0x76/0xb0 [vhost]
[ 194.183667] kthread+0x118/0x140
[ 194.190358] ret_from_fork+0x1f/0x30
[ 194.193670] </TASK>
In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-17