| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
linkwatch: use __dev_put() in callers to prevent UAF
After linkwatch_do_dev() calls __dev_put() to release the linkwatch
reference, the device refcount may drop to 1. At this point,
netdev_run_todo() can proceed (since linkwatch_sync_dev() sees an
empty list and returns without blocking), wait for the refcount to
become 1 via netdev_wait_allrefs_any(), and then free the device
via kobject_put().
This creates a use-after-free when __linkwatch_run_queue() tries to
call netdev_unlock_ops() on the already-freed device.
Note that adding netdev_lock_ops()/netdev_unlock_ops() pair in
netdev_run_todo() before kobject_put() would not work, because
netdev_lock_ops() is conditional - it only locks when
netdev_need_ops_lock() returns true. If the device doesn't require
ops_lock, linkwatch won't hold any lock, and netdev_run_todo()
acquiring the lock won't provide synchronization.
Fix this by moving __dev_put() from linkwatch_do_dev() to its
callers. The device reference logically pairs with de-listing the
device, so it's reasonable for the caller that did the de-listing
to release it. This allows placing __dev_put() after all device
accesses are complete, preventing UAF.
The bug can be reproduced by adding mdelay(2000) after
linkwatch_do_dev() in __linkwatch_run_queue(), then running:
ip tuntap add mode tun name tun_test
ip link set tun_test up
ip link set tun_test carrier off
ip link set tun_test carrier on
sleep 0.5
ip tuntap del mode tun name tun_test
KASAN report:
==================================================================
BUG: KASAN: use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
BUG: KASAN: use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
BUG: KASAN: use-after-free in __linkwatch_run_queue+0x865/0x8a0 net/core/link_watch.c:245
Read of size 8 at addr ffff88804de5c008 by task kworker/u32:10/8123
CPU: 0 UID: 0 PID: 8123 Comm: kworker/u32:10 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events_unbound linkwatch_event
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x156/0x4c9 mm/kasan/report.c:482
kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
__linkwatch_run_queue+0x865/0x8a0 net/core/link_watch.c:245
linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
================================================================== |
| In the Linux kernel, the following vulnerability has been resolved:
cgroup/dmem: avoid pool UAF
An UAF issue was observed:
BUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150
Write of size 8 at addr ffff888106715440 by task insmod/527
CPU: 4 UID: 0 PID: 527 Comm: insmod 6.19.0-rc7-next-20260129+ #11
Tainted: [O]=OOT_MODULE
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
kasan_report+0xca/0x100
kasan_check_range+0x39/0x1c0
page_counter_uncharge+0x65/0x150
dmem_cgroup_uncharge+0x1f/0x260
Allocated by task 527:
Freed by task 0:
The buggy address belongs to the object at ffff888106715400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 64 bytes inside of
freed 512-byte region [ffff888106715400, ffff888106715600)
The buggy address belongs to the physical page:
Memory state around the buggy address:
ffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
The issue occurs because a pool can still be held by a caller after its
associated memory region is unregistered. The current implementation frees
the pool even if users still hold references to it (e.g., before uncharge
operations complete).
This patch adds a reference counter to each pool, ensuring that a pool is
only freed when its reference count drops to zero. |
| Multiple ethernet Network Interface Card (NIC) device drivers do not pad frames with null bytes, which allows remote attackers to obtain information from previous packets or kernel memory by using malformed packets, as demonstrated by Etherleak. |
| The coda_pioctl function in the coda functionality (pioctl.c) for Linux kernel 2.6.9 and 2.4.x before 2.4.29 may allow local users to cause a denial of service (crash) or execute arbitrary code via negative vi.in_size or vi.out_size values, which may trigger a buffer overflow. |
| The Orinoco driver (orinoco.c) in Linux kernel 2.6.13 and earlier does not properly clear memory from a previously used packet whose length is increased, which allows remote attackers to obtain sensitive information. |
| Buffer overflow in the MoxaDriverIoctl function for the moxa serial driver (moxa.c) in Linux 2.2.x, 2.4.x, and 2.6.x before 2.6.22 allows local users to execute arbitrary code via a certain modified length value. |
| Race condition in run_posix_cpu_timers in Linux kernel before 2.6.16.21 allows local users to cause a denial of service (BUG_ON crash) by causing one CPU to attach a timer to a process that is exiting. |
| Buffer overflow in the ixj telephony card driver in Linux before 2.4.20 has unknown impact and attack vectors. |
| A numeric casting discrepancy in sdla_xfer in Linux kernel 2.6.x up to 2.6.5 and 2.4 up to 2.4.29-rc1 allows local users to read portions of kernel memory via a large len argument, which is received as an int but cast to a short, which prevents a read loop from filling a buffer. |
| Raw character devices (raw.c) in the Linux kernel 2.6.x call the wrong function before passing an ioctl to the block device, which crosses security boundaries by making kernel address space accessible from user space, a similar vulnerability to CVE-2005-1589. |
| The exit_thread function (process.c) in Linux kernel 2.6 through 2.6.5 does not invalidate the per-TSS io_bitmap pointers if a process obtains IO access permissions from the ioperm function but does not drop those permissions when it exits, which allows other processes to access the per-TSS pointers, access restricted memory locations, and possibly gain privileges. |
| The dvd_read_bca function in the DVD handling code in drivers/cdrom/cdrom.c in Linux kernel 2.2.16, and later versions, assigns the wrong value to a length variable, which allows local users to execute arbitrary code via a crafted USB Storage device that triggers a buffer overflow. |
| The Linux Kernel before 2.6.15.5 allows local users to cause a denial of service (NFS client panic) via unknown attack vectors related to the use of O_DIRECT (direct I/O). |
| Off-by-one vulnerability in CPIA driver of Linux kernel before 2.2.19 allows users to modify kernel memory. |
| Signedness error in (1) getsockopt and (2) setsockopt for Linux kernel before 2.2.19 allows local users to cause a denial of service. |
| Certain modifications to the Linux kernel 2.6.16 and earlier do not add the appropriate Linux Security Modules (LSM) file_permission hooks to the (1) readv and (2) writev functions, which might allow attackers to bypass intended access restrictions. |
| The OSS code for the Sound Blaster (sb16) driver in Linux 2.4.x before 2.4.26, when operating in 16 bit mode, does not properly handle certain sample sizes, which allows local users to cause a denial of service (crash) via a sample with an odd number of bytes. |
| The Vicam USB driver in Linux before 2.4.25 does not use the copy_from_user function when copying data from userspace to kernel space, which crosses security boundaries and allows local users to cause a denial of service. |
| The /proc handling (proc/base.c) Linux kernel 2.4 before 2.4.17 allows local users to cause a denial of service via unknown vectors that cause an invalid access of free memory. |
| Directory traversal vulnerability in smbfs in Linux 2.6.16 and earlier allows local users to escape chroot restrictions for an SMB-mounted filesystem via "..\\" sequences, a similar vulnerability to CVE-2006-1863. |
