Linux: >> Linux Kernel >> 3.10.28 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
smb: client: restrict implied bcc[0] exemption to responses without data area
smb2_check_message() has a long-standing quirk that accepts a response
whose calculated length is one byte larger than the bytes actually
received ("server can return one byte more due to implied bcc[0]").
This was introduced to accommodate servers that omit the trailing bcc[0]
overlap byte when no data area is present.
However, the exemption is applied unconditionally, regardless of whether
the command actually carries a data area (has_smb2_data_area[]). When a
response with a data area is subject to the +1 exemption, the reported
data can extend one byte beyond the bytes actually received, yet
smb2_check_message() still accepts it. The subsequent decoder then reads
past the end of the receive buffer. This is reachable during NEGOTIATE
and SESSION_SETUP, before the session is established.
The resulting out-of-bounds reads are visible under KASAN when mounting
against a non-conforming server; both the SPNEGO/negTokenInit and the
NTLMSSP challenge decoders are affected:
BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x16a7/0x1b00
Read of size 1 at addr ffff8880084d67c0 by task mount.cifs/81
CPU: 1 UID: 0 PID: 81 Comm: mount.cifs Not tainted 7.1.0-rc6 #1
Call Trace:
<TASK>
dump_stack_lvl+0x4e/0x70
print_report+0x157/0x4c9
kasan_report+0xce/0x100
asn1_ber_decoder+0x16a7/0x1b00
decode_negTokenInit+0x19/0x30
SMB2_negotiate+0x31d9/0x4c90
cifs_negotiate_protocol+0x1f2/0x3f0
cifs_get_smb_ses+0x93f/0x17e0
cifs_mount_get_session+0x7f/0x3a0
cifs_mount+0xb4/0xcf0
cifs_smb3_do_mount+0x23a/0x1500
smb3_get_tree+0x3b0/0x630
vfs_get_tree+0x82/0x2d0
fc_mount+0x10/0x1b0
path_mount+0x50d/0x1de0
__x64_sys_mount+0x20b/0x270
do_syscall_64+0xee/0x590
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 85:
kmem_cache_alloc_noprof+0x106/0x380
mempool_alloc_noprof+0x116/0x1e0
cifs_small_buf_get+0x31/0x80
allocate_buffers+0x10d/0x2b0
cifs_demultiplex_thread+0x1d5/0x1d50
kthread+0x2c6/0x390
ret_from_fork+0x36e/0x5a0
ret_from_fork_asm+0x1a/0x30
The buggy address is located 0 bytes to the right of
allocated 448-byte region [ffff8880084d6600, ffff8880084d67c0)
which belongs to the cache cifs_small_rq of size 448
BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x36/0x50
Read of size 329 at addr ffff88800726c678 by task mount.cifs/89
CPU: 0 UID: 0 PID: 89 Comm: mount.cifs Tainted: G B 7.1.0-rc6 #1
Call Trace:
<TASK>
dump_stack_lvl+0x4e/0x70
print_report+0x157/0x4c9
kasan_report+0xce/0x100
kasan_check_range+0x10f/0x1e0
__asan_memcpy+0x23/0x60
kmemdup_noprof+0x36/0x50
decode_ntlmssp_challenge+0x457/0x680
SMB2_sess_auth_rawntlmssp_negotiate+0x6f0/0xcb0
SMB2_sess_setup+0x219/0x4f0
cifs_setup_session+0x248/0xaf0
cifs_get_smb_ses+0xf79/0x17e0
cifs_mount_get_session+0x7f/0x3a0
cifs_mount+0xb4/0xcf0
cifs_smb3_do_mount+0x23a/0x1500
smb3_get_tree+0x3b0/0x630
vfs_get_tree+0x82/0x2d0
fc_mount+0x10/0x1b0
path_mount+0x50d/0x1de0
__x64_sys_mount+0x20b/0x270
do_syscall_64+0xee/0x590
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 93:
kmem_cache_alloc_noprof+0x106/0x380
mempool_alloc_noprof+0x116/0x1e0
cifs_small_buf_get+0x31/0x80
allocate_buffers+0x10d/0x2b0
cifs_demultiplex_thread+0x1d5/0x1d50
kthread+0x2c6/0x390
ret_from_fork+0x36e/0x5a0
ret_from_fork_asm+0x1a/0x30
The buggy address is located 120 bytes inside of
allocated 448-byte region [ffff88800726c600, ffff88800726c7c0)
which belongs to the cache cifs_small_rq of size 448
Restrict the +1 exemption to responses that have no data area, so that
it still covers the bcc[0] omission it was meant for. When a data area
is present, the +1 discrepancy instead means the reported data length
overruns the
---truncated---
CVSS Score
8.2
EPSS Score
0.005
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: vme_user: bound slave read/write to the kern_buf size
The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy
'count' bytes into/out of the fixed-size kern_buf (size_buf ==
PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without
bounding *ppos + count against size_buf.
vme_user_write()/vme_user_read() only clamp count to the VME window size
(image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the
user-supplied slave.size -- validated against the VME address space (up
to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window
exceeds 128 KiB, a write()/read() copies past the kern_buf allocation.
Clamp count against size_buf in both helpers, with an early return when
*ppos is already at/after the buffer end. *ppos is >= 0 here (the caller
rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors
the existing clamp in the MASTER-path helpers resource_to_user() /
resource_from_user(), and matches the read()/write() convention of a
short transfer at end-of-buffer.
Found by static analysis (CodeQL taint tracking + CBMC bounded model
checking) and confirmed dynamically under KASAN with the vme_fake bridge:
BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80
Write of size 262144 at addr ffff888004100000 by task trigger/68
_copy_from_user+0x2d/0x80
vme_user_write+0x13e/0x240 [vme_user]
vfs_write+0x1b8/0x7a0
ksys_write+0xb8/0x150
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
net: af_key: initialize alg_key_len for IPComp states
pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by
allocating x->calg and copying only the algorithm name:
x->calg = kmalloc_obj(*x->calg);
if (!x->calg) {
err = -ENOMEM;
goto out;
}
strcpy(x->calg->alg_name, a->name);
x->props.calgo = sa->sadb_sa_encrypt;
Unlike the authentication (x->aalg) and encryption (x->ealg) branches of
the same function, the compression branch never initializes
calg->alg_key_len. IPComp carries no key and the allocation only
reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field
is left containing uninitialized slab data.
calg->alg_key_len is later used as a length by xfrm_algo_clone() when an
IPComp state is cloned during XFRM_MSG_MIGRATE:
xfrm_state_migrate()
xfrm_state_clone_and_setup()
x->calg = xfrm_algo_clone(orig->calg);
kmemdup(orig, xfrm_alg_len(orig));
where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With
a non-zero garbage alg_key_len, kmemdup() reads past the end of the
68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating
it triggers (net-next, KASAN, init_on_alloc=0):
BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60
Read of size 4164 at addr ff11000025a74980 by task diag2/9287
CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1
Call Trace:
<TASK>
dump_stack_lvl+0x10e/0x1f0
print_report+0xf7/0x600
kasan_report+0xe4/0x120
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x23/0x60
kmemdup_noprof+0x44/0x60
xfrm_state_migrate+0x70a/0x1da0
xfrm_migrate+0x753/0x18a0
xfrm_do_migrate+0xb47/0xf10
xfrm_user_rcv_msg+0x411/0xb50
netlink_rcv_skb+0x158/0x420
xfrm_netlink_rcv+0x71/0x90
netlink_unicast+0x584/0x850
netlink_sendmsg+0x8b0/0xdc0
____sys_sendmsg+0x9f7/0xb90
___sys_sendmsg+0x134/0x1d0
__sys_sendmsg+0x16d/0x220
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 9287:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
pfkey_add+0x2652/0x2ea0
pfkey_process+0x6d0/0x830
pfkey_sendmsg+0x42c/0x850
__sys_sendto+0x461/0x4b0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ff11000025a74980
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
allocated 68-byte region [ff11000025a74980, ff11000025a749c4)
Depending on the uninitialized value the same field can instead request
an oversized kmemdup() allocation and make the migration clone fail.
The XFRM netlink path is not affected: verify_one_alg() rejects an
XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via
XFRM_MSG_NEWSA is always self-consistent.
Initialize calg->alg_key_len to 0, matching the aalg/ealg branches.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes
Reject invalid `net.ipv4.tcp_reordering` values before they reach TCP
socket state. The sysctl is stored as an `int` but copied into the
`u32` `tp->reordering` field for new sockets, so negative writes wrap
to large values.
With `tcp_mtu_probing=2`, the wrapped value can overflow the
`tcp_mtu_probe()` size calculation and drive the MTU probing path into
an out-of-bounds read. Route `tcp_reordering` writes through
`proc_dointvec_minmax()` and require it to be at least 1. Also require
`tcp_max_reordering` to be at least 1 so the configured maximum cannot
become negative either.
When registering the table for a non-init network namespace, relocate
`extra2` pointers that refer into `init_net.ipv4` so the
`tcp_reordering` upper bound follows that namespace's
`tcp_max_reordering`.
Harden `tcp_mtu_probe()` itself by computing `size_needed` as `u64`.
This keeps the send queue and window checks from being bypassed through
signed integer overflow.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
netpoll: fix a use-after-free on shutdown path
There is a use-after-free error on netpoll, which is clearly detected by
KASAN.
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80
Read of size 1 at addr ... by task kworker/9:1
Workqueue: events queue_process
Call Trace:
skb_dequeue+0x1e/0xb0
queue_process+0x2c/0x600
process_scheduled_works+0x4b6/0x850
worker_thread+0x414/0x5a0
Allocated by task 242:
__netpoll_setup+0x201/0x4a0
netpoll_setup+0x249/0x550
enabled_store+0x32f/0x380
Freed by task 0:
kfree+0x1b7/0x540
rcu_core+0x3f8/0x7a0
The problem happens when there is a pending TX worker running in
parallel with the cleanup path.
This is what happens on netpoll shutdown path:
1) __netpoll_cleanup() is called
2) set dev->npinfo to NULL
3) call_rcu() with rcu_cleanup_netpoll_info()
3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with
cancel_delayed_work(), but doesn't wait for the worker to finish
4) and kfree(npinfo);
Because 3.1) doesn't really cancel the work, as the comment says "we
can't call cancel_delayed_work_sync here, as we are in softirq", the TX
worker can run after 4).
Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through
the work item via container_of().
Use disable_delayed_work_sync() to ensure the worker is completely
stopped and prevent any future re-arming attempts. Once npinfo is set
to NULL, senders will bail out and not queue new work. The disable flag
ensures any in-flight re-arming attempts also fail silently.
In the future, we can do the cleanup inline here without needing the
npinfo->rcu rcu_head, but that is net-next material.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: zero chainstack array
sashiko reports:
looking at ebtables table
translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
free?
If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
CPU 2, the cleanup loop will blindly decrement and call vfree() on
newinfo->chainstack[1].
Not a real-world bug, such allocation isn't expected to fail
in the first place.
CVSS Score
7.0
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: terminate table name before find_table_lock()
update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.
BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
Read of size 1 at addr ffff8880119dfb20 by task exploit/147
Call Trace:
...
string (lib/vsprintf.c:648 lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
__request_module (kernel/module/kmod.c:150)
do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
update_counters (net/bridge/netfilter/ebtables.c:1440)
do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
nf_setsockopt (net/netfilter/nf_sockopt.c:101)
ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
raw_setsockopt (net/ipv4/raw.c:847)
__sys_setsockopt (net/socket.c:2393)
...
compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers
Syzbot reported a hung task in nilfs_transaction_begin() where multiple
tasks performing chmod() on a nilfs2 mount blocked for over 143 seconds
waiting to acquire ns_segctor_sem for read:
INFO: task syz.0.17:5918 blocked for more than 143 seconds.
Call Trace:
schedule+0x164/0x360
rwsem_down_read_slowpath+0x6d9/0x940
down_read+0x99/0x2e0
nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
nilfs_setattr+0x124/0x2c0 fs/nilfs2/inode.c:921
notify_change+0xc1a/0xf40
chmod_common+0x273/0x4a0
do_fchmodat+0x12d/0x230
The writer holding ns_segctor_sem was a concurrent
NILFS_IOCTL_CLEAN_SEGMENTS caller, stuck inside printk while emitting
per-element warnings from nilfs_sufile_updatev():
__nilfs_msg+0x373/0x450 fs/nilfs2/super.c:78
nilfs_sufile_updatev+0x21c/0x6d0 fs/nilfs2/sufile.c:186
nilfs_sufile_freev fs/nilfs2/sufile.h:93 [inline]
nilfs_free_segments fs/nilfs2/segment.c:1140 [inline]
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1261 [inline]
nilfs_segctor_do_construct+0x1f55/0x76c0
nilfs_clean_segments+0x3bd/0xa50
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline]
nilfs_ioctl+0x261f/0x2780
The root cause is that user-supplied segment numbers are not validated
before nilfs_clean_segments() begins doing work; the range check on
each segnum is performed deep inside the call chain by
nilfs_sufile_updatev(), which emits a nilfs_warn() per invalid entry
while still holding the segctor lock and the sufile mi_sem. Under load
(repeated invocations across multiple mounts saturating the global
printk path), the cumulative printk latency keeps ns_segctor_sem held
long enough to trip the hung_task watchdog, blocking concurrent
operations such as chmod() that need ns_segctor_sem for read.
Fix by validating the contents of kbufs[4] in nilfs_clean_segments()
immediately after acquiring ns_segctor_sem via nilfs_transaction_lock().
Holding ns_segctor_sem serializes the check against
nilfs_ioctl_resize(), which can modify ns_nsegments, so the validation
uses a consistent value. Out-of-range segment numbers are rejected
with -EINVAL before any segment-cleaning work begins, so the bad
entries never reach the per-element diagnostic path inside
nilfs_sufile_updatev().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
HID: appleir: fix UAF on pending key_up_timer in remove()
appleir_remove() runs hid_hw_stop() before timer_delete_sync().
hid_hw_stop() synchronously unregisters the HID input device via
hid_disconnect() -> hidinput_disconnect() -> input_unregister_device(),
which drops the last reference and frees the underlying input_dev when
no userspace handle holds it open.
key_up_tick() reads appleir->input_dev and calls input_report_key() /
input_sync() on it. The timer is armed from appleir_raw_event() with
a HZ/8 (~125 ms) timeout on every keydown and key-repeat report. If a
key was pressed shortly before the device is disconnected, the timer
can fire after hid_hw_stop() has freed input_dev but before the
teardown drains it.
A simple reorder is not sufficient. Putting the timer drain first
still leaves a window where a USB URB completion (raw_event) running
during hid_hw_stop() can call mod_timer() and re-arm the timer, which
then fires after hidinput_disconnect() has freed input_dev. The same
URB-completion window also lets raw_event() reach key_up(), key_down()
and battery_flat() directly, all of which dereference
appleir->input_dev.
Introduce a 'removing' flag on struct appleir, gated by the existing
spinlock. appleir_remove() sets the flag under the lock and then
shuts down the timer with timer_shutdown_sync(), which both drains any
in-flight callback and permanently disables further mod_timer() calls.
appleir_raw_event() and key_up_tick() bail out early if the flag is
set, so no path can arm or run the timer, or dereference
appleir->input_dev, after remove() has started tearing down.
The keyrepeat and flatbattery branches of appleir_raw_event()
previously called into the input layer without holding the spinlock;
take it now so the flag check is well-defined. This incidentally
closes a pre-existing read-side race on appleir->current_key in the
keyrepeat branch.
This bug is structurally a sibling of commit 4db2af929279 ("HID:
appletb-kbd: fix UAF in inactivity-timer cleanup path") and has been
present since the driver was introduced.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
usb: free iso schedules on failed submit
EHCI and FOTG210 isochronous submits build an ehci_iso_sched before
linking the URB to the endpoint queue, and keep the staged schedule in
urb->hcpriv until iso_stream_schedule() and the link helpers consume it.
If the controller is no longer accessible, or usb_hcd_link_urb_to_ep()
fails, submit jumps to done_not_linked before that handoff happens and
leaks the staged schedule still attached to urb->hcpriv.
Free the staged schedule from done_not_linked when submit fails before
the URB is linked and clear urb->hcpriv after the free.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. As we do not have an
EHCI host controller with a USB isochronous device to test with, no
runtime testing was able to be performed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
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