Linux: >> Linux Kernel >> 2.6.37.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential null-ptr-deref in device_add()
I got the following null-ptr-deref report while doing fault injection test:
BUG: kernel NULL pointer dereference, address: 0000000000000058
CPU: 2 PID: 278 Comm: 37-i2c-ds2482 Tainted: G B W N 6.1.0-rc3+
RIP: 0010:klist_put+0x2d/0xd0
Call Trace:
<TASK>
klist_remove+0xf1/0x1c0
device_release_driver_internal+0x196/0x210
bus_remove_device+0x1bd/0x240
device_add+0xd3d/0x1100
w1_add_master_device+0x476/0x490 [wire]
ds2482_probe+0x303/0x3e0 [ds2482]
This is how it happened:
w1_alloc_dev()
// The dev->driver is set to w1_master_driver.
memcpy(&dev->dev, device, sizeof(struct device));
device_add()
bus_add_device()
dpm_sysfs_add() // It fails, calls bus_remove_device.
// error path
bus_remove_device()
// The dev->driver is not null, but driver is not bound.
__device_release_driver()
klist_remove(&dev->p->knode_driver) <-- It causes null-ptr-deref.
// normal path
bus_probe_device() // It's not called yet.
device_bind_driver()
If dev->driver is set, in the error path after calling bus_add_device()
in device_add(), bus_remove_device() is called, then the device will be
detached from driver. But device_bind_driver() is not called yet, so it
causes null-ptr-deref while access the 'knode_driver'. To fix this, set
dev->driver to null in the error path before calling bus_remove_device().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-12-30
In the Linux kernel, the following vulnerability has been resolved:
ksm: use range-walk function to jump over holes in scan_get_next_rmap_item
Currently, scan_get_next_rmap_item() walks every page address in a VMA to
locate mergeable pages. This becomes highly inefficient when scanning
large virtual memory areas that contain mostly unmapped regions, causing
ksmd to use large amount of cpu without deduplicating much pages.
This patch replaces the per-address lookup with a range walk using
walk_page_range(). The range walker allows KSM to skip over entire
unmapped holes in a VMA, avoiding unnecessary lookups. This problem was
previously discussed in [1].
Consider the following test program which creates a 32 TiB mapping in the
virtual address space but only populates a single page:
#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
/* 32 TiB */
const size_t size = 32ul * 1024 * 1024 * 1024 * 1024;
int main() {
char *area = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0);
if (area == MAP_FAILED) {
perror("mmap() failed\n");
return -1;
}
/* Populate a single page such that we get an anon_vma. */
*area = 0;
/* Enable KSM. */
madvise(area, size, MADV_MERGEABLE);
pause();
return 0;
}
$ ./ksm-sparse &
$ echo 1 > /sys/kernel/mm/ksm/run
Without this patch ksmd uses 100% of the cpu for a long time (more then 1
hour in my test machine) scanning all the 32 TiB virtual address space
that contain only one mapped page. This makes ksmd essentially deadlocked
not able to deduplicate anything of value. With this patch ksmd walks
only the one mapped page and skips the rest of the 32 TiB virtual address
space, making the scan fast using little cpu.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-12-16
In the Linux kernel, the following vulnerability has been resolved:
scsi: ses: Fix possible desc_ptr out-of-bounds accesses
Sanitize possible desc_ptr out-of-bounds accesses in
ses_enclosure_data_process().
CVSS Score
7.1
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer
smatch error:
sound/pci/ac97/ac97_codec.c:2354 snd_ac97_mixer() error:
we previously assumed 'rac97' could be null (see line 2072)
remove redundant assignment, return error if rac97 is NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
fbdev: omapfb: lcd_mipid: Fix an error handling path in mipid_spi_probe()
If 'mipid_detect()' fails, we must free 'md' to avoid a memory leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: hif_usb: fix memory leak of remain_skbs
hif_dev->remain_skb is allocated and used exclusively in
ath9k_hif_usb_rx_stream(). It is implied that an allocated remain_skb is
processed and subsequently freed (in error paths) only during the next
call of ath9k_hif_usb_rx_stream().
So, if the urbs are deallocated between those two calls due to the device
deinitialization or suspend, it is possible that ath9k_hif_usb_rx_stream()
is not called next time and the allocated remain_skb is leaked. Our local
Syzkaller instance was able to trigger that.
remain_skb makes sense when receiving two consecutive urbs which are
logically linked together, i.e. a specific data field from the first skb
indicates a cached skb to be allocated, memcpy'd with some data and
subsequently processed in the next call to ath9k_hif_usb_rx_stream(). Urbs
deallocation supposedly makes that link irrelevant so we need to free the
cached skb in those cases.
Fix the leak by introducing a function to explicitly free remain_skb (if
it is not NULL) when the rx urbs have been deallocated. remain_skb is NULL
when it has not been allocated at all (hif_dev struct is kzalloced) or
when it has been processed in next call to ath9k_hif_usb_rx_stream().
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
md: fix soft lockup in status_resync
status_resync() will calculate 'curr_resync - recovery_active' to show
user a progress bar like following:
[============>........] resync = 61.4%
'curr_resync' and 'recovery_active' is updated in md_do_sync(), and
status_resync() can read them concurrently, hence it's possible that
'curr_resync - recovery_active' can overflow to a huge number. In this
case status_resync() will be stuck in the loop to print a large amount
of '=', which will end up soft lockup.
Fix the problem by setting 'resync' to MD_RESYNC_ACTIVE in this case,
this way resync in progress will be reported to user.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix possible data races in gfs2_show_options()
Some fields such as gt_logd_secs of the struct gfs2_tune are accessed
without holding the lock gt_spin in gfs2_show_options():
val = sdp->sd_tune.gt_logd_secs;
if (val != 30)
seq_printf(s, ",commit=%d", val);
And thus can cause data races when gfs2_show_options() and other functions
such as gfs2_reconfigure() are concurrently executed:
spin_lock(>->gt_spin);
gt->gt_logd_secs = newargs->ar_commit;
To fix these possible data races, the lock sdp->sd_tune.gt_spin is
acquired before accessing the fields of gfs2_tune and released after these
accesses.
Further changes by Andreas:
- Don't hold the spin lock over the seq_printf operations.
CVSS Score
7.0
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
usb: host: xhci: Fix potential memory leak in xhci_alloc_stream_info()
xhci_alloc_stream_info() allocates stream context array for stream_info
->stream_ctx_array with xhci_alloc_stream_ctx(). When some error occurs,
stream_info->stream_ctx_array is not released, which will lead to a
memory leak.
We can fix it by releasing the stream_info->stream_ctx_array with
xhci_free_stream_ctx() on the error path to avoid the potential memory
leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
r6040: Fix kmemleak in probe and remove
There is a memory leaks reported by kmemleak:
unreferenced object 0xffff888116111000 (size 2048):
comm "modprobe", pid 817, jiffies 4294759745 (age 76.502s)
hex dump (first 32 bytes):
00 c4 0a 04 81 88 ff ff 08 10 11 16 81 88 ff ff ................
08 10 11 16 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff815bcd82>] kmalloc_trace+0x22/0x60
[<ffffffff827e20ee>] phy_device_create+0x4e/0x90
[<ffffffff827e6072>] get_phy_device+0xd2/0x220
[<ffffffff827e7844>] mdiobus_scan+0xa4/0x2e0
[<ffffffff827e8be2>] __mdiobus_register+0x482/0x8b0
[<ffffffffa01f5d24>] r6040_init_one+0x714/0xd2c [r6040]
...
The problem occurs in probe process as follows:
r6040_init_one:
mdiobus_register
mdiobus_scan <- alloc and register phy_device,
the reference count of phy_device is 3
r6040_mii_probe
phy_connect <- connect to the first phy_device,
so the reference count of the first
phy_device is 4, others are 3
register_netdev <- fault inject succeeded, goto error handling path
// error handling path
err_out_mdio_unregister:
mdiobus_unregister(lp->mii_bus);
err_out_mdio:
mdiobus_free(lp->mii_bus); <- the reference count of the first
phy_device is 1, it is not released
and other phy_devices are released
// similarly, the remove process also has the same problem
The root cause is traced to the phy_device is not disconnected when
removes one r6040 device in r6040_remove_one() or on error handling path
after r6040_mii probed successfully. In r6040_mii_probe(), a net ethernet
device is connected to the first PHY device of mii_bus, in order to
notify the connected driver when the link status changes, which is the
default behavior of the PHY infrastructure to handle everything.
Therefore the phy_device should be disconnected when removes one r6040
device or on error handling path.
Fix it by adding phy_disconnect() when removes one r6040 device or on
error handling path after r6040_mii probed successfully.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07