Linux: >> Linux Kernel >> 2.16.12 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:
register_ftrace_function
ftrace_startup
__register_ftrace_function
...
add_ftrace_ops(&ftrace_ops_list, ops)
...
...
ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
...
return 0 // ops is in the ftrace_ops_list.
When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
ftrace_shutdown
if (unlikely(ftrace_disabled))
return -ENODEV; // return here, __unregister_ftrace_function is not executed,
// as a result, ops is still in the ftrace_ops_list
__unregister_ftrace_function
...
If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:
is_ftrace_trampoline
ftrace_ops_trampoline
do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!
Syzkaller reports as follows:
[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b
[ 1203.508039] #PF: supervisor read access in kernel mode
[ 1203.508798] #PF: error_code(0x0000) - not-present page
[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0
[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI
[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8
[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0
[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00
[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246
[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866
[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b
[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07
[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399
[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008
[ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
[ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0
[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Therefore, when ftrace_startup_enable fails, we need to rollback registration
process and remove ops from ftrace_ops_list.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
fbdev: fb_pm2fb: Avoid potential divide by zero error
In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be
copied from user, then go through `fb_set_var()` and
`info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`.
Along the path, `var->pixclock` won't be modified. This function checks
whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is
zero, there will be a divide by zero error. So, it is necessary to check
whether denominator is zero to avoid crash. As this bug is found by
Syzkaller, logs are listed below.
divide error in pm2fb_check_var
Call Trace:
<TASK>
fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
net: fix refcount bug in sk_psock_get (2)
Syzkaller reports refcount bug as follows:
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 3605 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19
Modules linked in:
CPU: 1 PID: 3605 Comm: syz-executor208 Not tainted 5.18.0-syzkaller-03023-g7e062cda7d90 #0
<TASK>
__refcount_add_not_zero include/linux/refcount.h:163 [inline]
__refcount_inc_not_zero include/linux/refcount.h:227 [inline]
refcount_inc_not_zero include/linux/refcount.h:245 [inline]
sk_psock_get+0x3bc/0x410 include/linux/skmsg.h:439
tls_data_ready+0x6d/0x1b0 net/tls/tls_sw.c:2091
tcp_data_ready+0x106/0x520 net/ipv4/tcp_input.c:4983
tcp_data_queue+0x25f2/0x4c90 net/ipv4/tcp_input.c:5057
tcp_rcv_state_process+0x1774/0x4e80 net/ipv4/tcp_input.c:6659
tcp_v4_do_rcv+0x339/0x980 net/ipv4/tcp_ipv4.c:1682
sk_backlog_rcv include/net/sock.h:1061 [inline]
__release_sock+0x134/0x3b0 net/core/sock.c:2849
release_sock+0x54/0x1b0 net/core/sock.c:3404
inet_shutdown+0x1e0/0x430 net/ipv4/af_inet.c:909
__sys_shutdown_sock net/socket.c:2331 [inline]
__sys_shutdown_sock net/socket.c:2325 [inline]
__sys_shutdown+0xf1/0x1b0 net/socket.c:2343
__do_sys_shutdown net/socket.c:2351 [inline]
__se_sys_shutdown net/socket.c:2349 [inline]
__x64_sys_shutdown+0x50/0x70 net/socket.c:2349
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
During SMC fallback process in connect syscall, kernel will
replaces TCP with SMC. In order to forward wakeup
smc socket waitqueue after fallback, kernel will sets
clcsk->sk_user_data to origin smc socket in
smc_fback_replace_callbacks().
Later, in shutdown syscall, kernel will calls
sk_psock_get(), which treats the clcsk->sk_user_data
as psock type, triggering the refcnt warning.
So, the root cause is that smc and psock, both will use
sk_user_data field. So they will mismatch this field
easily.
This patch solves it by using another bit(defined as
SK_USER_DATA_PSOCK) in PTRMASK, to mark whether
sk_user_data points to a psock object or not.
This patch depends on a PTRMASK introduced in commit f1ff5ce2cd5e
("net, sk_msg: Clear sk_user_data pointer on clone if tagged").
For there will possibly be more flags in the sk_user_data field,
this patch also refactor sk_user_data flags code to be more generic
to improve its maintainability.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: Fix use-after-free Read in usb_udc_uevent()
The syzbot fuzzer found a race between uevent callbacks and gadget
driver unregistration that can cause a use-after-free bug:
---------------------------------------------------------------
BUG: KASAN: use-after-free in usb_udc_uevent+0x11f/0x130
drivers/usb/gadget/udc/core.c:1732
Read of size 8 at addr ffff888078ce2050 by task udevd/2968
CPU: 1 PID: 2968 Comm: udevd Not tainted 5.19.0-rc4-next-20220628-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
06/29/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
kasan_report+0xbe/0x1f0 mm/kasan/report.c:495
usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1732
dev_uevent+0x290/0x770 drivers/base/core.c:2424
---------------------------------------------------------------
The bug occurs because usb_udc_uevent() dereferences udc->driver but
does so without acquiring the udc_lock mutex, which protects this
field. If the gadget driver is unbound from the udc concurrently with
uevent processing, the driver structure may be accessed after it has
been deallocated.
To prevent the race, we make sure that the routine holds the mutex
around the racing accesses.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
HID: hidraw: fix memory leak in hidraw_release()
Free the buffered reports before deleting the list entry.
BUG: memory leak
unreferenced object 0xffff88810e72f180 (size 32):
comm "softirq", pid 0, jiffies 4294945143 (age 16.080s)
hex dump (first 32 bytes):
64 f3 c6 6a d1 88 07 04 00 00 00 00 00 00 00 00 d..j............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814ac6c3>] kmemdup+0x23/0x50 mm/util.c:128
[<ffffffff8357c1d2>] kmemdup include/linux/fortify-string.h:440 [inline]
[<ffffffff8357c1d2>] hidraw_report_event+0xa2/0x150 drivers/hid/hidraw.c:521
[<ffffffff8356ddad>] hid_report_raw_event+0x27d/0x740 drivers/hid/hid-core.c:1992
[<ffffffff8356e41e>] hid_input_report+0x1ae/0x270 drivers/hid/hid-core.c:2065
[<ffffffff835f0d3f>] hid_irq_in+0x1ff/0x250 drivers/hid/usbhid/hid-core.c:284
[<ffffffff82d3c7f9>] __usb_hcd_giveback_urb+0xf9/0x230 drivers/usb/core/hcd.c:1670
[<ffffffff82d3cc26>] usb_hcd_giveback_urb+0x1b6/0x1d0 drivers/usb/core/hcd.c:1747
[<ffffffff82ef1e14>] dummy_timer+0x8e4/0x14c0 drivers/usb/gadget/udc/dummy_hcd.c:1988
[<ffffffff812f50a8>] call_timer_fn+0x38/0x200 kernel/time/timer.c:1474
[<ffffffff812f5586>] expire_timers kernel/time/timer.c:1519 [inline]
[<ffffffff812f5586>] __run_timers.part.0+0x316/0x430 kernel/time/timer.c:1790
[<ffffffff812f56e4>] __run_timers kernel/time/timer.c:1768 [inline]
[<ffffffff812f56e4>] run_timer_softirq+0x44/0x90 kernel/time/timer.c:1803
[<ffffffff848000e6>] __do_softirq+0xe6/0x2ea kernel/softirq.c:571
[<ffffffff81246db0>] invoke_softirq kernel/softirq.c:445 [inline]
[<ffffffff81246db0>] __irq_exit_rcu kernel/softirq.c:650 [inline]
[<ffffffff81246db0>] irq_exit_rcu+0xc0/0x110 kernel/softirq.c:662
[<ffffffff84574f02>] sysvec_apic_timer_interrupt+0xa2/0xd0 arch/x86/kernel/apic/apic.c:1106
[<ffffffff84600c8b>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649
[<ffffffff8458a070>] native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
[<ffffffff8458a070>] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
[<ffffffff8458a070>] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
[<ffffffff8458a070>] acpi_idle_do_entry+0xc0/0xd0 drivers/acpi/processor_idle.c:554
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
media: pvrusb2: fix memory leak in pvr_probe
The error handling code in pvr2_hdw_create forgets to unregister the
v4l2 device. When pvr2_hdw_create returns back to pvr2_context_create,
it calls pvr2_context_destroy to destroy context, but mp->hdw is NULL,
which leads to that pvr2_hdw_destroy directly returns.
Fix this by adding v4l2_device_unregister to decrease the refcount of
usb interface.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
bpf: Don't redirect packets with invalid pkt_len
Syzbot found an issue [1]: fq_codel_drop() try to drop a flow whitout any
skbs, that is, the flow->head is null.
The root cause, as the [2] says, is because that bpf_prog_test_run_skb()
run a bpf prog which redirects empty skbs.
So we should determine whether the length of the packet modified by bpf
prog or others like bpf_prog_test is valid before forwarding it directly.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
Input: iforce - wake up after clearing IFORCE_XMIT_RUNNING flag
syzbot is reporting hung task at __input_unregister_device() [1], for
iforce_close() waiting at wait_event_interruptible() with dev->mutex held
is blocking input_disconnect_device() from __input_unregister_device().
It seems that the cause is simply that commit c2b27ef672992a20 ("Input:
iforce - wait for command completion when closing the device") forgot to
call wake_up() after clear_bit().
Fix this problem by introducing a helper that calls clear_bit() followed
by wake_up_all().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8712: fix use after free bugs
_Read/Write_MACREG callbacks are NULL so the read/write_macreg_hdl()
functions don't do anything except free the "pcmd" pointer. It
results in a use after free. Delete them.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
vt: Clear selection before changing the font
When changing the console font with ioctl(KDFONTOP) the new font size
can be bigger than the previous font. A previous selection may thus now
be outside of the new screen size and thus trigger out-of-bounds
accesses to graphics memory if the selection is removed in
vc_do_resize().
Prevent such out-of-memory accesses by dropping the selection before the
various con_font_set() console handlers are called.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-06-18