CVE-2022-50780
Unknown Unknown - Not Provided
Use-After-Free in Linux Kernel net Subsystem's nfqnl_nf_hook_drop Function

Publication date: 2025-12-24

Last updated on: 2025-12-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed When the ops_init() interface is invoked to initialize the net, but ops->init() fails, data is released. However, the ptr pointer in net->gen is invalid. In this case, when nfqnl_nf_hook_drop() is invoked to release the net, invalid address access occurs. The process is as follows: setup_net() ops_init() data = kzalloc(...) ---> alloc "data" net_assign_generic() ---> assign "date" to ptr in net->gen ... ops->init() ---> failed ... kfree(data); ---> ptr in net->gen is invalid ... ops_exit_list() ... nfqnl_nf_hook_drop() *q = nfnl_queue_pernet(net) ---> q is invalid The following is the Call Trace information: BUG: KASAN: use-after-free in nfqnl_nf_hook_drop+0x264/0x280 Read of size 8 at addr ffff88810396b240 by task ip/15855 Call Trace: <TASK> dump_stack_lvl+0x8e/0xd1 print_report+0x155/0x454 kasan_report+0xba/0x1f0 nfqnl_nf_hook_drop+0x264/0x280 nf_queue_nf_hook_drop+0x8b/0x1b0 __nf_unregister_net_hook+0x1ae/0x5a0 nf_unregister_net_hooks+0xde/0x130 ops_exit_list+0xb0/0x170 setup_net+0x7ac/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> Allocated by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0xa1/0xb0 __kmalloc+0x49/0xb0 ops_init+0xe7/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x155/0x1b0 slab_free_freelist_hook+0x11b/0x220 __kmem_cache_free+0xa4/0x360 ops_init+0xb9/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
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Meta Information
Published
2025-12-24
Last Modified
2025-12-24
Generated
2026-05-07
AI Q&A
2025-12-24
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a use-after-free (UAF) issue in the Linux kernel's net subsystem, specifically in the nfqnl_nf_hook_drop() function. It occurs when the ops_init() function fails during network initialization. Although data is allocated and assigned to a pointer in net->gen, if ops->init() fails, the allocated data is freed but the pointer remains invalid. Later, when nfqnl_nf_hook_drop() tries to access this invalid pointer to release network resources, it results in invalid memory access, causing a use-after-free error.


How can this vulnerability impact me? :

This vulnerability can lead to invalid memory access in the Linux kernel, potentially causing system crashes, instability, or kernel panics. Exploiting this use-after-free bug could allow an attacker to execute arbitrary code with kernel privileges or cause denial of service by crashing the system.


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