| 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. |
| Race condition in the (1) add_key, (2) request_key, and (3) keyctl functions in Linux kernel 2.6.x allows local users to cause a denial of service (crash) or read sensitive kernel memory by modifying the length of a string argument between the time that the kernel calculates the length and when it copies the data into kernel memory. |
| mknod in Linux 2.2 follows symbolic links, which could allow local users to overwrite files or gain privileges. |
| Multiple race conditions in the handling of O_DIRECT in Linux kernel prior to version 2.4.22 could cause stale data to be returned from the disk when handling sparse files, or cause incorrect data to be returned when a file is truncated as it is being read, which might allow local users to obtain sensitive data that was originally owned by other users, a different vulnerability than CVE-2003-0018. |
| 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. |
| Buffer overflow in Linux su command gives root access to local users. |
| The ip_push_pending_frames function in Linux 2.4.x and 2.6.x before 2.6.16 increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows remote attackers to conduct an Idle Scan (nmap -sI) attack, which bypasses intended protections against such attacks. |
| Integer overflow in the do_replace function in netfilter for Linux before 2.6.16-rc3, when using "virtualization solutions" such as OpenVZ, allows local users with CAP_NET_ADMIN rights to cause a buffer overflow in the copy_from_user function. |
| sys_mbind in mempolicy.c in Linux kernel 2.6.16 and earlier does not sanity check the maxnod variable before making certain computations for the get_nodes function, which has unknown impact and attack vectors. |
| Various routines for the ppc64 architecture on Linux kernel 2.6 prior to 2.6.2 and 2.4 prior to 2.4.24 do not use the copy_from_user function when copying data from userspace to kernelspace, which crosses security boundaries and allows local users to cause a denial of service. |
| The kernel strncpy function in Linux 2.4 and 2.5 does not %NUL pad the buffer on architectures other than x86, as opposed to the expected behavior of strncpy as implemented in libc, which could lead to information leaks. |
| The source code tar archive of the Linux kernel 2.6.16, 2.6.17.11, and possibly other versions specifies weak permissions (0666 and 0777) for certain files and directories, which might allow local users to insert Trojan horse source code that would be used during the next kernel compilation. NOTE: another researcher disputes the vulnerability, stating that he finds "Not a single world-writable file or directory." CVE analysis as of 20060908 indicates that permissions will only be weak under certain unusual or insecure scenarios |
| 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 kernel 2.4.x and 2.6.x up to 2.6.16 allows local users to bypass IPC permissions and modify a readonly attachment of shared memory by using mprotect to give write permission to the attachment. NOTE: some original raw sources combined this issue with CVE-2006-1524, but they are different bugs. |
| Memory leak in __setlease in fs/locks.c in Linux kernel before 2.6.16.16 allows attackers to cause a denial of service (memory consumption) via unspecified actions related to an "uninitialised return value," aka "slab leak." |
| Linux kernel before 2.6.13 allows local users to cause a denial of service (crash) via a dio transfer from the sg driver to memory mapped (mmap) IO space. |
| Buffer overflow in the USB Gadget RNDIS implementation in the Linux kernel before 2.6.16 allows remote attackers to cause a denial of service (kmalloc'd memory corruption) via a remote NDIS response to OID_GEN_SUPPORTED_LIST, which causes memory to be allocated for the reply data but not the reply structure. |
| 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. |
| The Linux kernel before 2.6.16.9 and the FreeBSD kernel, when running on AMD64 and other 7th and 8th generation AuthenticAMD processors, only save/restore the FOP, FIP, and FDP x87 registers in FXSAVE/FXRSTOR when an exception is pending, which allows one process to determine portions of the state of floating point instructions of other processes, which can be leveraged to obtain sensitive information such as cryptographic keys. NOTE: this is the documented behavior of AMD64 processors, but it is inconsistent with Intel processors in a security-relevant fashion that was not addressed by the kernels. |
