high CVSS 7.8

CVE-2022-48912·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: netfilter: fix use-after-free in __nf_register_net_hook() We must not dereference @new_hooks after nf_hook_mutex has been released, because other threads might have freed our allocated hooks already. BUG: KASAN: use-after-free in nf_hook_entries_get_hook_ops include/linux/netfilter.h:130 [inline] BUG: KASAN: use-after-free in hooks_validate net/netfilter/core.c:171 [inline] BUG: KASAN: use-after-free in __nf_register_net_hook+0x77a/0x820 net/netfilter/core.c:438 Read of size 2 at addr ffff88801c1a8000 by task syz-executor237/4430 CPU: 1 PID: 4430 Comm: syz-executor237 Not tainted 5.17.0-rc5-syzkaller-00306-g2293be58d6a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 nf_hook_entries_get_hook_ops include/linux/netfilter.h:130 [inline] hooks_validate net/netfilter/core.c:171 [inline] __nf_register_net_hook+0x77a/0x820 net/netfilter/core.c:438 nf_register_net_hook+0x114/0x170 net/netfilter/core.c:571 nf_register_net_hooks+0x59/0xc0 net/netfilter/core.c:587 nf_synproxy_ipv6_init+0x85/0xe0 net/netfilter/nf_synproxy_core.c:1218 synproxy_tg6_check+0x30d/0x560 net/ipv6/netfilter/ip6t_SYNPROXY.c:81 xt_check_target+0x26c/0x9e0 net/netfilter/x_tables.c:1038 check_target net/ipv6/netfilter/ip6_tables.c:530 [inline] find_check_entry.constprop.0+0x7f1/0x9e0 net/ipv6/netfilter/ip6_tables.c:573 translate_table+0xc8b/0x1750 net/ipv6/netfilter/ip6_tables.c:735 do_replace net/ipv6/netfilter/ip6_tables.c:1153 [inline] do_ip6t_set_ctl+0x56e/0xb90 net/ipv6/netfilter/ip6_tables.c:1639 nf_setsockopt+0x83/0xe0 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0x122/0x180 net/ipv6/ipv6_sockglue.c:1024 rawv6_setsockopt+0xd3/0x6a0 net/ipv6/raw.c:1084 __sys_setsockopt+0x2db/0x610 net/socket.c:2180 __do_sys_setsockopt net/socket.c:2191 [inline] __se_sys_setsockopt net/socket.c:2188 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f65a1ace7d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f65a1a7f308 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f65a1ace7d9 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 00007f65a1b574c8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00007f65a1b55130 R13: 00007f65a1b574c0 R14: 00007f65a1b24090 R15: 0000000000022000 </TASK> The buggy address belongs to the page: page:ffffea0000706a00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c1a8 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001c1b108 ffffea000046dd08 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO), pid 4430, ts 1061781545818, free_ts 1061791488993 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 __alloc_pages_node include/linux/gfp.h:572 [inline] alloc_pages_node include/linux/gfp.h:595 [inline] kmalloc_large_node+0x62/0x130 mm/slub.c:4438 __kmalloc_node+0x35a/0x4a0 mm/slub. ---truncated---

Severity
high
Software
Kernel
Fixed in
5.16.13
Published
2024-08-22

Affected versions

From: 5.16

Until: 5.16.13

Fixed in: 5.16.13

How to fix this CVE

Update the Linux kernel to version 5.16.13 or later to resolve a use-after-free vulnerability in the netfilter hook registration mechanism. This vulnerability can lead to memory corruption when netfilter rules are dynamically loaded, potentially allowing privilege escalation. Systems running kernel versions 5.16.0 through 5.16.12 should prioritize this patch application.

sudo dnf update kernel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your kernel version with `uname -r`. Look for kernel versions between 5.16.0 and 5.16.12.
  2. Step 2: Verify if netfilter modules are loaded by running `lsmod | grep nf_` to confirm the vulnerable component is active.
  3. Step 3: Search system logs for KASAN errors related to netfilter with `dmesg | grep -i 'use-after-free' | grep netfilter` or check `/var/log/kern.log` for similar patterns.
  4. Step 4: After applying the patch, reboot the system and verify the new kernel version with `uname -r` matches 5.16.13 or later.

FAQ

What is CVE-2022-48912?

CVE-2022-48912 is a use-after-free vulnerability in the Linux kernel's netfilter subsystem that occurs during hook registration. When netfilter rules are registered concurrently, memory can be freed prematurely while still being accessed, leading to memory corruption and potential privilege escalation.

Is CVE-2022-48912 being actively exploited?

No, this vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available, though the high CVSS score of 7.8 warrants prompt patching.

What versions of Kernel are affected by CVE-2022-48912?

Linux kernel versions 5.16.0 through 5.16.12 are vulnerable. Kernel 5.16.13 and later versions contain the fix.

How do I check if my server is vulnerable to CVE-2022-48912?

Run `uname -r` and check if the output shows a kernel version between 5.16.0 and 5.16.12. If so, your system is vulnerable and requires an immediate kernel update.

Does Defensia detect CVE-2022-48912?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-48912 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2024-42256CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
CVE-2024-36031CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: keys: Fix overwrite of key expiration on instantiation The expiry time of a key is unconditionally overwritten during instantiation, defaulting to turn it permanent. This causes a problem for DNS resolution as the expiration set by user-space is overwritten to TIME64_MAX, disabling further DNS updates. Fix this by restoring the condition that key_set_expiry is only called when the pre-parser sets a specific expiry.
CVE-2024-38612CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix invalid unregister error path The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL is not defined. In that case if seg6_hmac_init() fails, the genl_unregister_family() isn't called. This issue exist since commit 46738b1317e1 ("ipv6: sr: add option to control lwtunnel support"), and commit 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref") replaced unregister_pernet_subsys() with genl_unregister_family() in this error path.
CVE-2024-38623CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)
CVE-2021-47548CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port() The if statement: if (port >= DSAF_GE_NUM) return; limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6). To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2022-48912. Free for 1 server.

Get started free