Linux: >> Linux Kernel >> 5.1 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ipv6: Add lwtunnel encap size of all siblings in nexthop calculation
In function rt6_nlmsg_size(), the length of nexthop is calculated
by multipling the nexthop length of fib6_info and the number of
siblings. However if the fib6_info has no lwtunnel but the siblings
have lwtunnels, the nexthop length is less than it should be, and
it will trigger a warning in inet6_rt_notify() as follows:
WARNING: CPU: 0 PID: 6082 at net/ipv6/route.c:6180 inet6_rt_notify+0x120/0x130
......
Call Trace:
<TASK>
fib6_add_rt2node+0x685/0xa30
fib6_add+0x96/0x1b0
ip6_route_add+0x50/0xd0
inet6_rtm_newroute+0x97/0xa0
rtnetlink_rcv_msg+0x156/0x3d0
netlink_rcv_skb+0x5a/0x110
netlink_unicast+0x246/0x350
netlink_sendmsg+0x250/0x4c0
sock_sendmsg+0x66/0x70
___sys_sendmsg+0x7c/0xd0
__sys_sendmsg+0x5d/0xb0
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
This bug can be reproduced by script:
ip -6 addr add 2002::2/64 dev ens2
ip -6 route add 100::/64 via 2002::1 dev ens2 metric 100
for i in 10 20 30 40 50 60 70;
do
ip link add link ens2 name ipv_$i type ipvlan
ip -6 addr add 2002::$i/64 dev ipv_$i
ifconfig ipv_$i up
done
for i in 10 20 30 40 50 60;
do
ip -6 route append 100::/64 encap ip6 dst 2002::$i via 2002::1
dev ipv_$i metric 100
done
ip -6 route append 100::/64 via 2002::1 dev ipv_70 metric 100
This patch fixes it by adding nexthop_len of every siblings using
rt6_nh_nlmsg_size().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
kobject: Add sanity check for kset->kobj.ktype in kset_register()
When I register a kset in the following way:
static struct kset my_kset;
kobject_set_name(&my_kset.kobj, "my_kset");
ret = kset_register(&my_kset);
A null pointer dereference exception is occurred:
[ 4453.568337] Unable to handle kernel NULL pointer dereference at \
virtual address 0000000000000028
... ...
[ 4453.810361] Call trace:
[ 4453.813062] kobject_get_ownership+0xc/0x34
[ 4453.817493] kobject_add_internal+0x98/0x274
[ 4453.822005] kset_register+0x5c/0xb4
[ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset]
... ...
Because I didn't initialize my_kset.kobj.ktype.
According to the description in Documentation/core-api/kobject.rst:
- A ktype is the type of object that embeds a kobject. Every structure
that embeds a kobject needs a corresponding ktype.
So add sanity check to make sure kset->kobj.ktype is not NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed
Following process will trigger an infinite loop in ubi_wl_put_peb():
ubifs_bgt ubi_bgt
ubifs_leb_unmap
ubi_leb_unmap
ubi_eba_unmap_leb
ubi_wl_put_peb wear_leveling_worker
e1 = rb_entry(rb_first(&ubi->used)
e2 = get_peb_for_wl(ubi)
ubi_io_read_vid_hdr // return err (flash fault)
out_error:
ubi->move_from = ubi->move_to = NULL
wl_entry_destroy(ubi, e1)
ubi->lookuptbl[e->pnum] = NULL
retry:
e = ubi->lookuptbl[pnum]; // return NULL
if (e == ubi->move_from) { // NULL == NULL gets true
goto retry; // infinite loop !!!
$ top
PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND
7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0
Fix it by:
1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has
been removed from 'ubi->lookuptbl'.
2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an
use-after-free problem for wl entry in ubi_wl_put_peb().
Fetch a reproducer in [Link].
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
iommu: Fix error unwind in iommu_group_alloc()
If either iommu_group_grate_file() fails then the
iommu_group is leaked.
Destroy it on these error paths.
Found by kselftest/iommu/iommufd_fail_nth
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/gfx: disable gfx9 cp_ecc_error_irq only when enabling legacy gfx ras
gfx9 cp_ecc_error_irq is only enabled when legacy gfx ras is assert.
So in gfx_v9_0_hw_fini, interrupt disablement for cp_ecc_error_irq
should be executed under such condition, otherwise, an amdgpu_irq_put
calltrace will occur.
[ 7283.170322] RIP: 0010:amdgpu_irq_put+0x45/0x70 [amdgpu]
[ 7283.170964] RSP: 0018:ffff9a5fc3967d00 EFLAGS: 00010246
[ 7283.170967] RAX: ffff98d88afd3040 RBX: ffff98d89da20000 RCX: 0000000000000000
[ 7283.170969] RDX: 0000000000000000 RSI: ffff98d89da2bef8 RDI: ffff98d89da20000
[ 7283.170971] RBP: ffff98d89da20000 R08: ffff98d89da2ca18 R09: 0000000000000006
[ 7283.170973] R10: ffffd5764243c008 R11: 0000000000000000 R12: 0000000000001050
[ 7283.170975] R13: ffff98d89da38978 R14: ffffffff999ae15a R15: ffff98d880130105
[ 7283.170978] FS: 0000000000000000(0000) GS:ffff98d996f00000(0000) knlGS:0000000000000000
[ 7283.170981] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7283.170983] CR2: 00000000f7a9d178 CR3: 00000001c42ea000 CR4: 00000000003506e0
[ 7283.170986] Call Trace:
[ 7283.170988] <TASK>
[ 7283.170989] gfx_v9_0_hw_fini+0x1c/0x6d0 [amdgpu]
[ 7283.171655] amdgpu_device_ip_suspend_phase2+0x101/0x1a0 [amdgpu]
[ 7283.172245] amdgpu_device_suspend+0x103/0x180 [amdgpu]
[ 7283.172823] amdgpu_pmops_freeze+0x21/0x60 [amdgpu]
[ 7283.173412] pci_pm_freeze+0x54/0xc0
[ 7283.173419] ? __pfx_pci_pm_freeze+0x10/0x10
[ 7283.173425] dpm_run_callback+0x98/0x200
[ 7283.173430] __device_suspend+0x164/0x5f0
v2: drop gfx11 as it's fixed in a different solution by retiring cp_ecc_irq funcs(Hawking)
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
iw_cxgb4: Fix potential NULL dereference in c4iw_fill_res_cm_id_entry()
This condition needs to match the previous "if (epcp->state == LISTEN) {"
exactly to avoid a NULL dereference of either "listen_ep" or "ep". The
problem is that "epcp" has been re-assigned so just testing
"if (epcp->state == LISTEN) {" a second time is not sufficient.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
ubifs: Fix memory leak in alloc_wbufs()
kmemleak reported a sequence of memory leaks, and show them as following:
unreferenced object 0xffff8881575f8400 (size 1024):
comm "mount", pid 19625, jiffies 4297119604 (age 20.383s)
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:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff8881798a6e00 (size 512):
comm "mount", pid 19677, jiffies 4297121912 (age 37.816s)
hex dump (first 32 bytes):
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs]
[<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
The problem is that the ubifs_wbuf_init() returns an error in the
loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes
that were successfully alloced before are not freed.
Fix it by adding error hanging path in alloc_wbufs() which frees
the memory alloced before when ubifs_wbuf_init() returns an error.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
FS: JFS: Fix null-ptr-deref Read in txBegin
Syzkaller reported an issue where txBegin may be called
on a superblock in a read-only mounted filesystem which leads
to NULL pointer deref. This could be solved by checking if
the filesystem is read-only before calling txBegin, and returning
with appropiate error code.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish()
When the driver calls cx23885_risc_buffer() to prepare the buffer, the
function call dma_alloc_coherent may fail, resulting in a empty buffer
risc->cpu. Later when we free the buffer or access the buffer, null ptr
deref is triggered.
This bug is similar to the following one:
https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.
We believe the bug can be also dynamically triggered from user side.
Similarly, we fix this by checking the return value of cx23885_risc_buffer()
and the value of risc->cpu before buffer free.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01
In the Linux kernel, the following vulnerability has been resolved:
io_uring: wait interruptibly for request completions on exit
WHen the ring exits, cleanup is done and the final cancelation and
waiting on completions is done by io_ring_exit_work. That function is
invoked by kworker, which doesn't take any signals. Because of that, it
doesn't really matter if we wait for completions in TASK_INTERRUPTIBLE
or TASK_UNINTERRUPTIBLE state. However, it does matter to the hung task
detection checker!
Normally we expect cancelations and completions to happen rather
quickly. Some test cases, however, will exit the ring and park the
owning task stopped (eg via SIGSTOP). If the owning task needs to run
task_work to complete requests, then io_ring_exit_work won't make any
progress until the task is runnable again. Hence io_ring_exit_work can
trigger the hung task detection, which is particularly problematic if
panic-on-hung-task is enabled.
As the ring exit doesn't take signals to begin with, have it wait
interruptibly rather than uninterruptibly. io_uring has a separate
stuck-exit warning that triggers independently anyway, so we're not
really missing anything by making this switch.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-01