| 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. |
| Integer overflow in the do_brk function for the brk system call in Linux kernel 2.4.22 and earlier allows local users to gain root privileges. |
| KDE klock allows local users to kill arbitrary processes by specifying an arbitrary PID in the .kss.pid file. |
| KDE kppp allows local users to create a directory in an arbitrary location via the HOME environmental variable. |
| Linux kernel 2.6.16-rc2 and earlier, when running on x86_64 systems with preemption enabled, allows local users to cause a denial of service (oops) via multiple ptrace tasks that perform single steps, which can cause corruption of the DEBUG_STACK stack during the do_debug function call. |
| Versions of rpcbind including Linux, IRIX, and Wietse Venema's rpcbind allow a remote attacker to insert and delete entries by spoofing a source address. |
| Race condition in the Radeon DRI driver for Linux kernel 2.6.8.1 allows local users with DRI privileges to execute arbitrary code as root. |
| Unknown vulnerability in the eflags checking in the 32-bit ptrace emulation for the Linux kernel on AMD64 systems allows local users to gain privileges. |
| The load_elf_library in the Linux kernel before 2.6.11.6 allows local users to cause a denial of service (kernel crash) via a crafted ELF library or executable, which causes a free of an invalid pointer. |
| Integer overflow in the vc_resize function in the Linux kernel 2.4 and 2.6 before 2.6.10 allows local users to cause a denial of service (kernel crash) via a short new screen value, which leads to a buffer overflow. |
| Linux kernel 2.6.10 and 2.6.11rc1-bk6 uses different size types for offset arguments to the proc_file_read and locks_read_proc functions, which leads to a heap-based buffer overflow when a signed comparison causes negative integers to be used in a positive context. |
| Race condition in SELinux 2.6.x through 2.6.9 allows local users to cause a denial of service (kernel crash) via SOCK_SEQPACKET unix domain sockets, which are not properly handled in the sock_dgram_sendmsg function. |
| Memory leak in direct-io.c in Linux kernel 2.6.x before 2.6.10 allows local users to cause a denial of service (memory consumption) via certain O_DIRECT (direct IO) write requests. |
| Netfilter in Linux kernel 2.6.8.1 allows remote attackers to cause a denial of service (kernel crash) via crafted IP packet fragments. |
| Integer overflow in Linux kernel 2.6 allows local users to overwrite kernel memory by writing to a sysfs file. |
| The hugepage code (hugetlb.c) in Linux kernel 2.6, possibly 2.6.12 and 2.6.13, in certain configurations, allows local users to cause a denial of service (crash) by triggering an mmap error before a prefault, which causes an error in the unmap_hugepage_area function. |
| The MAC module in Netfilter in Linux kernel 2.4.1 through 2.4.11, when configured to filter based on MAC addresses, allows remote attackers to bypass packet filters via small packets. |
| ip_conntrack_proto_icmp.c in ctnetlink in Linux kernel 2.6.14 up to 2.6.14.3 allows attackers to cause a denial of service (kernel oops) via a message without ICMP ID (ICMP_ID) information, which leads to a null dereference. |
| Buffer overflow in the ISO9660 file system component for Linux kernel 2.4.x, 2.5.x and 2.6.x, allows local users with physical access to overflow kernel memory and execute arbitrary code via a malformed CD containing a long symbolic link entry. |
