| 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. |
| The udp_v6_get_port function in udp.c in Linux 2.6 before 2.6.14-rc5, when running IPv6, allows local users to cause a denial of service (infinite loop and crash). |
| The Linux 2.0 kernel IP stack does not properly calculate the size of an ICMP citation, which causes it to include portions of unauthorized memory in ICMP error responses. |
| The smb_recv_trans2 function call in the samba filesystem (smbfs) in Linux kernel 2.4 and 2.6 does not properly handle the re-assembly of fragmented packets correctly, which could allow remote samba servers to (1) read arbitrary kernel information or (2) raise a counter value to an arbitrary number by sending the first part of the fragmented packet multiple times. |
| Vulnerability when Network Address Translation (NAT) is enabled in Linux 2.2.10 and earlier with ipchains, or FreeBSD 3.2 with ipfw, allows remote attackers to cause a denial of service (kernel panic) via a ping -R (record route) command. |
| 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. |
| rpc.mountd on Linux, Ultrix, and possibly other operating systems, allows remote attackers to determine the existence of a file on the server by attempting to mount that file, which generates different error messages depending on whether the file exists or not. |
| Multiple "overflows" in the io_edgeport driver for Linux kernel 2.4.x have unknown impact and unknown attack vectors. |
| The elf_core_dump function in binfmt_elf.c for Linux kernel 2.x.x to 2.2.27-rc2, 2.4.x to 2.4.31-pre1, and 2.6.x to 2.6.12-rc4 allows local users to execute arbitrary code via an ELF binary that, in certain conditions involving the create_elf_tables function, causes a negative length argument to pass a signed integer comparison, leading to a buffer overflow. |
| Linux 2.0.37 does not properly encode the Custom segment limit, which allows local users to gain root privileges by accessing and modifying kernel memory. |
| The ping command in Linux 2.0.3x allows local users to cause a denial of service by sending large packets with the -R (record route) option. |
| Nestea variation of teardrop IP fragmentation denial of service. |
| IP masquerading in Linux 2.2.x allows remote attackers to route UDP packets through the internal interface by modifying the external source IP address and port number to match those of an established connection. |
| Linux bdash game has a buffer overflow that allows local users to gain root access. |
| Unspecified vulnerability in the ptrace MIPS assembly code in Linux kernel 2.4 before 2.4.17 allows local users to gain privileges via unknown vectors. |
| The Linux 2.2.x kernel does not restrict the number of Unix domain sockets as defined by the wmem_max parameter, which allows local users to cause a denial of service by requesting a large number of sockets. |
| Unspecified vulnerability in the sctp_make_abort_user function in the SCTP implementation in Linux 2.6.x before 2.6.17.10 and 2.4.23 up to 2.4.33 allows local users to cause a denial of service (panic) and possibly gain root privileges via unknown attack vectors. |
| Linux 2.2.3 and earlier allow a remote attacker to perform an IP fragmentation attack, causing a denial of service. |
| The auto-reap of child processes in Linux kernel 2.6 before 2.6.15 includes processes with ptrace attached, which leads to a dangling ptrace reference and allows local users to cause a denial of service (crash) and gain root privileges. |
