Linux: >> Linux Kernel >> 6.1.1 Security Vulnerabilities
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
In the Linux kernel, the following vulnerability has been resolved:
tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
When the best clk is searched, we iterate over all possible clk.
If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt7601u: fix an integer underflow
Fix an integer underflow that leads to a null pointer dereference in
'mt7601u_rx_skb_from_seg()'. The variable 'dma_len' in the URB packet
could be manipulated, which could trigger an integer underflow of
'seg_len' in 'mt7601u_rx_process_seg()'. This underflow subsequently
causes the 'bad_frame' checks in 'mt7601u_rx_skb_from_seg()' to be
bypassed, eventually leading to a dereference of the pointer 'p', which
is a null pointer.
Ensure that 'dma_len' is greater than 'min_seg_len'.
Found by a modified version of syzkaller.
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 12 Comm: ksoftirqd/0 Tainted: G W O 5.14.0+
#139
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_add_rx_frag+0x143/0x370
Code: e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 86 01 00 00 4c 8d 7d 08 44
89 68 08 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02
00 0f 85 cd 01 00 00 48 8b 45 08 a8 01 0f 85 3d 01 00 00
RSP: 0018:ffffc900000cfc90 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888115520dc0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff8881118430c0 RDI: ffff8881118430f8
RBP: 0000000000000000 R08: 0000000000000e09 R09: 0000000000000010
R10: ffff888111843017 R11: ffffed1022308602 R12: 0000000000000000
R13: 0000000000000e09 R14: 0000000000000010 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff88811a800000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004035af40 CR3: 00000001157f2000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
mt7601u_rx_tasklet+0xc73/0x1270
? mt7601u_submit_rx_buf.isra.0+0x510/0x510
? tasklet_action_common.isra.0+0x79/0x2f0
tasklet_action_common.isra.0+0x206/0x2f0
__do_softirq+0x1b5/0x880
? tasklet_unlock+0x30/0x30
run_ksoftirqd+0x26/0x50
smpboot_thread_fn+0x34f/0x7d0
? smpboot_register_percpu_thread+0x370/0x370
kthread+0x3a1/0x480
? set_kthread_struct+0x120/0x120
ret_from_fork+0x1f/0x30
Modules linked in: 88XXau(O) 88x2bu(O)
---[ end trace 57f34f93b4da0f9b ]---
RIP: 0010:skb_add_rx_frag+0x143/0x370
Code: e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 86 01 00 00 4c 8d 7d 08 44
89 68 08 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02
00 0f 85 cd 01 00 00 48 8b 45 08 a8 01 0f 85 3d 01 00 00
RSP: 0018:ffffc900000cfc90 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888115520dc0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff8881118430c0 RDI: ffff8881118430f8
RBP: 0000000000000000 R08: 0000000000000e09 R09: 0000000000000010
R10: ffff888111843017 R11: ffffed1022308602 R12: 0000000000000000
R13: 0000000000000e09 R14: 0000000000000010 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff88811a800000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004035af40 CR3: 00000001157f2000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL
OPDESC() simply indexes into nfsd4_ops[] by the op's operation
number, without range checking that value. It assumes callers are
careful to avoid calling it with an out-of-bounds opnum value.
nfsd4_decode_compound() is not so careful, and can invoke OPDESC()
with opnum set to OP_ILLEGAL, which is 10044 -- well beyond the end
of nfsd4_ops[].
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent
In some specific situations, the return value of __bch_btree_node_alloc
may be NULL. This may lead to a potential NULL pointer dereference in
caller function like a calling chain :
btree_split->bch_btree_node_alloc->__bch_btree_node_alloc.
Fix it by initializing the return value in __bch_btree_node_alloc.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (xgene) Fix ioremap and memremap leak
Smatch reports:
drivers/hwmon/xgene-hwmon.c:757 xgene_hwmon_probe() warn:
'ctx->pcc_comm_addr' from ioremap() not released on line: 757.
This is because in drivers/hwmon/xgene-hwmon.c:701 xgene_hwmon_probe(),
ioremap and memremap is not released, which may cause a leak.
To fix this, ioremap and memremap is modified to devm_ioremap and
devm_memremap.
[groeck: Fixed formatting and subject]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
fs: hfsplus: remove WARN_ON() from hfsplus_cat_{read,write}_inode()
syzbot is hitting WARN_ON() in hfsplus_cat_{read,write}_inode(), for
crafted filesystem image can contain bogus length. There conditions are
not kernel bugs that can justify kernel to panic.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
xfrm: Zero padding when dumping algos and encap
When copying data to user-space we should ensure that only valid
data is copied over. Padding in structures may be filled with
random (possibly sensitve) data and should never be given directly
to user-space.
This patch fixes the copying of xfrm algorithms and the encap
template in xfrm_user so that padding is zeroed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
tun: Fix memory leak for detached NAPI queue.
syzkaller reported [0] memory leaks of sk and skb related to the TUN
device with no repro, but we can reproduce it easily with:
struct ifreq ifr = {}
int fd_tun, fd_tmp;
char buf[4] = {};
fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0);
ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE;
ioctl(fd_tun, TUNSETIFF, &ifr);
ifr.ifr_flags = IFF_DETACH_QUEUE;
ioctl(fd_tun, TUNSETQUEUE, &ifr);
fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0);
ifr.ifr_flags = IFF_UP;
ioctl(fd_tmp, SIOCSIFFLAGS, &ifr);
write(fd_tun, buf, sizeof(buf));
close(fd_tun);
If we enable NAPI and multi-queue on a TUN device, we can put skb into
tfile->sk.sk_write_queue after the queue is detached. We should prevent
it by checking tfile->detached before queuing skb.
Note this must be done under tfile->sk.sk_write_queue.lock because write()
and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would
be a small race window:
write() ioctl(IFF_DETACH_QUEUE)
`- tun_get_user `- __tun_detach
|- if (tfile->detached) |- tun_disable_queue
| `-> false | `- tfile->detached = tun
| `- tun_queue_purge
|- spin_lock_bh(&queue->lock)
`- __skb_queue_tail(queue, skb)
Another solution is to call tun_queue_purge() when closing and
reattaching the detached queue, but it could paper over another
problems. Also, we do the same kind of test for IFF_NAPI_FRAGS.
[0]:
unreferenced object 0xffff88801edbc800 (size 2048):
comm "syz-executor.1", pid 33269, jiffies 4295743834 (age 18.756s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<000000008c16ea3d>] __do_kmalloc_node mm/slab_common.c:965 [inline]
[<000000008c16ea3d>] __kmalloc+0x4a/0x130 mm/slab_common.c:979
[<000000003addde56>] kmalloc include/linux/slab.h:563 [inline]
[<000000003addde56>] sk_prot_alloc+0xef/0x1b0 net/core/sock.c:2035
[<000000003e20621f>] sk_alloc+0x36/0x2f0 net/core/sock.c:2088
[<0000000028e43843>] tun_chr_open+0x3d/0x190 drivers/net/tun.c:3438
[<000000001b0f1f28>] misc_open+0x1a6/0x1f0 drivers/char/misc.c:165
[<000000004376f706>] chrdev_open+0x111/0x300 fs/char_dev.c:414
[<00000000614d379f>] do_dentry_open+0x2f9/0x750 fs/open.c:920
[<000000008eb24774>] do_open fs/namei.c:3636 [inline]
[<000000008eb24774>] path_openat+0x143f/0x1a30 fs/namei.c:3791
[<00000000955077b5>] do_filp_open+0xce/0x1c0 fs/namei.c:3818
[<00000000b78973b0>] do_sys_openat2+0xf0/0x260 fs/open.c:1356
[<00000000057be699>] do_sys_open fs/open.c:1372 [inline]
[<00000000057be699>] __do_sys_openat fs/open.c:1388 [inline]
[<00000000057be699>] __se_sys_openat fs/open.c:1383 [inline]
[<00000000057be699>] __x64_sys_openat+0x83/0xf0 fs/open.c:1383
[<00000000a7d2182d>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<00000000a7d2182d>] do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80
[<000000004cc4e8c4>] entry_SYSCALL_64_after_hwframe+0x72/0xdc
unreferenced object 0xffff88802f671700 (size 240):
comm "syz-executor.1", pid 33269, jiffies 4295743854 (age 18.736s)
hex dump (first 32 bytes):
68 c9 db 1e 80 88 ff ff 68 c9 db 1e 80 88 ff ff h.......h.......
00 c0 7b 2f 80 88 ff ff 00 c8 db 1e 80 88 ff ff ..{/............
backtrace:
[<00000000e9d9fdb6>] __alloc_skb+0x223/0x250 net/core/skbuff.c:644
[<000000002c3e4e0b>] alloc_skb include/linux/skbuff.h:1288 [inline]
[<000000002c3e4e0b>] alloc_skb_with_frags+0x6f/0x350 net/core/skbuff.c:6378
[<00000000825f98d7>] sock_alloc_send_pskb+0x3ac/0x3e0 net/core/sock.c:2729
[<00000000e9eb3df3>] tun_alloc_skb drivers/net/tun.c:1529 [inline]
[<
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
srcu: Delegate work to the boot cpu if using SRCU_SIZE_SMALL
Commit 994f706872e6 ("srcu: Make Tree SRCU able to operate without
snp_node array") assumes that cpu 0 is always online. However, there
really are situations when some other CPU is the boot CPU, for example,
when booting a kdump kernel with the maxcpus=1 boot parameter.
On PowerPC, the kdump kernel can hang as follows:
...
[ 1.740036] systemd[1]: Hostname set to <xyz.com>
[ 243.686240] INFO: task systemd:1 blocked for more than 122 seconds.
[ 243.686264] Not tainted 6.1.0-rc1 #1
[ 243.686272] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 243.686281] task:systemd state:D stack:0 pid:1 ppid:0 flags:0x00042000
[ 243.686296] Call Trace:
[ 243.686301] [c000000016657640] [c000000016657670] 0xc000000016657670 (unreliable)
[ 243.686317] [c000000016657830] [c00000001001dec0] __switch_to+0x130/0x220
[ 243.686333] [c000000016657890] [c000000010f607b8] __schedule+0x1f8/0x580
[ 243.686347] [c000000016657940] [c000000010f60bb4] schedule+0x74/0x140
[ 243.686361] [c0000000166579b0] [c000000010f699b8] schedule_timeout+0x168/0x1c0
[ 243.686374] [c000000016657a80] [c000000010f61de8] __wait_for_common+0x148/0x360
[ 243.686387] [c000000016657b20] [c000000010176bb0] __flush_work.isra.0+0x1c0/0x3d0
[ 243.686401] [c000000016657bb0] [c0000000105f2768] fsnotify_wait_marks_destroyed+0x28/0x40
[ 243.686415] [c000000016657bd0] [c0000000105f21b8] fsnotify_destroy_group+0x68/0x160
[ 243.686428] [c000000016657c40] [c0000000105f6500] inotify_release+0x30/0xa0
[ 243.686440] [c000000016657cb0] [c0000000105751a8] __fput+0xc8/0x350
[ 243.686452] [c000000016657d00] [c00000001017d524] task_work_run+0xe4/0x170
[ 243.686464] [c000000016657d50] [c000000010020e94] do_notify_resume+0x134/0x140
[ 243.686478] [c000000016657d80] [c00000001002eb18] interrupt_exit_user_prepare_main+0x198/0x270
[ 243.686493] [c000000016657de0] [c00000001002ec60] syscall_exit_prepare+0x70/0x180
[ 243.686505] [c000000016657e10] [c00000001000bf7c] system_call_vectored_common+0xfc/0x280
[ 243.686520] --- interrupt: 3000 at 0x7fffa47d5ba4
[ 243.686528] NIP: 00007fffa47d5ba4 LR: 0000000000000000 CTR: 0000000000000000
[ 243.686538] REGS: c000000016657e80 TRAP: 3000 Not tainted (6.1.0-rc1)
[ 243.686548] MSR: 800000000000d033 <SF,EE,PR,ME,IR,DR,RI,LE> CR: 42044440 XER: 00000000
[ 243.686572] IRQMASK: 0
[ 243.686572] GPR00: 0000000000000006 00007ffffa606710 00007fffa48e7200 0000000000000000
[ 243.686572] GPR04: 0000000000000002 000000000000000a 0000000000000000 0000000000000001
[ 243.686572] GPR08: 000001000c172dd0 0000000000000000 0000000000000000 0000000000000000
[ 243.686572] GPR12: 0000000000000000 00007fffa4ff4bc0 0000000000000000 0000000000000000
[ 243.686572] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 243.686572] GPR20: 0000000132dfdc50 000000000000000e 0000000000189375 0000000000000000
[ 243.686572] GPR24: 00007ffffa606ae0 0000000000000005 000001000c185490 000001000c172570
[ 243.686572] GPR28: 000001000c172990 000001000c184850 000001000c172e00 00007fffa4fedd98
[ 243.686683] NIP [00007fffa47d5ba4] 0x7fffa47d5ba4
[ 243.686691] LR [0000000000000000] 0x0
[ 243.686698] --- interrupt: 3000
[ 243.686708] INFO: task kworker/u16:1:24 blocked for more than 122 seconds.
[ 243.686717] Not tainted 6.1.0-rc1 #1
[ 243.686724] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 243.686733] task:kworker/u16:1 state:D stack:0 pid:24 ppid:2 flags:0x00000800
[ 243.686747] Workqueue: events_unbound fsnotify_mark_destroy_workfn
[ 243.686758] Call Trace:
[ 243.686762] [c0000000166736e0] [c00000004fd91000] 0xc00000004fd91000 (unreliable)
[ 243.686775] [c0000000166738d0] [c00000001001dec0] __switch_to+0x130/0x220
[ 243.686788] [c000000016673930] [c000000010f607b8] __schedule+0x1f8/0x
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07