high CVSS 7.1

CVE-2022-48999·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: ipv4: Handle attempt to delete multipath route when fib_info contains an nh reference Gwangun Jung reported a slab-out-of-bounds access in fib_nh_match: fib_nh_match+0xf98/0x1130 linux-6.0-rc7/net/ipv4/fib_semantics.c:961 fib_table_delete+0x5f3/0xa40 linux-6.0-rc7/net/ipv4/fib_trie.c:1753 inet_rtm_delroute+0x2b3/0x380 linux-6.0-rc7/net/ipv4/fib_frontend.c:874 Separate nexthop objects are mutually exclusive with the legacy multipath spec. Fix fib_nh_match to return if the config for the to be deleted route contains a multipath spec while the fib_info is using a nexthop object.

Severity
high
Software
Kernel
Fixed in
6.0.12
Published
2024-10-21

Affected versions

From: 5.16

Until: 6.0.12

Fixed in: 6.0.12

How to fix this CVE

Update your Linux kernel to version 6.0.12 or later to resolve a memory access vulnerability in the IPv4 routing subsystem. This flaw affects kernel versions 5.16 through 6.0.11 and can be triggered when attempting to delete multipath routes that conflict with nexthop object configurations. Apply the patch immediately via your distribution's kernel update mechanism to prevent potential denial-of-service conditions.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your current kernel version: uname -r — compare against affected range 5.16.x to 6.0.11
  2. Verify if IPv4 multipath routing is configured: ip route show | grep -i nexthop
  3. Search system logs for fib_nh_match or routing-related crashes: dmesg | grep -i 'fib_nh_match\|slab-out-of-bounds'
  4. After patching, confirm the new kernel is active by rebooting and re-running uname -r to verify version 6.0.12 or later

FAQ

What is CVE-2022-48999?

CVE-2022-48999 is a memory safety vulnerability in the Linux kernel's IPv4 routing table deletion logic that occurs when trying to remove a multipath route on systems using separate nexthop objects. The flaw causes an out-of-bounds memory access that can trigger a kernel panic or denial of service.

Is CVE-2022-48999 being actively exploited?

No, CVE-2022-48999 is not listed in the CISA Known Exploited Vulnerabilities catalog and no public exploits are available. However, the vulnerability can be easily triggered by local users with network configuration privileges.

What versions of Kernel are affected by CVE-2022-48999?

Linux kernel versions 5.16.0 through 6.0.11 are vulnerable. The fix was released in kernel 6.0.12 and backported to stable branches.

How do I check if my server is vulnerable to CVE-2022-48999?

Run 'uname -r' and verify your kernel version falls between 5.16 and 6.0.11. Additionally, check if multipath routing is configured with 'ip route show | grep nexthop' — if both conditions are true, your system is exposed.

Does Defensia detect CVE-2022-48999?

Yes — Defensia's CVE advisory scanner compares installed kernel versions against the NVD database. If a vulnerable kernel is installed on a monitored server, CVE-2022-48999 will appear in your dashboard with distribution-specific remediation steps.

Related Kernel CVEs

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CVE-2026-64439CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: crypto: krb5 - filter out async aead implementations at alloc krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL completion callback and treat any negative return from crypto_aead_{encrypt,decrypt}() as terminal, falling through to kfree_sensitive(buffer). When the encrypt_name resolves to an async AEAD instance the request returns -EINPROGRESS, the buffer is freed while the backend's worker still holds a pointer, and the worker dereferences the freed slab on completion. KASAN report under UML+SLUB with a synthetic async aead backend bound to krb5->encrypt_name: BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7 The helpers were written synchronously, so filter the async instances out at allocation time instead of plumbing crypto_wait_req() through every call site. Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and net/ceph/crypto.c on systems with an async AEAD provider bound to the krb5 enctype name.
CVE-2026-64066CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_read_to_pagecache() to pause on subreq failure Fix netfs_read_to_pagecache() so that it pauses the generation of new subrequests if an already-issued subrequest fails.
CVE-2026-64383CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.
CVE-2026-64067CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing barriers when accessing stream->subrequests locklessly The list of subrequests attached to stream->subrequests is accessed without locks by netfs_collect_read_results() and netfs_collect_write_results(), and then they access subreq->flags without taking a barrier after getting the subreq pointer from the list. Relatedly, the functions that build the list don't use any sort of write barrier when constructing the list to make sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if no lock is taken. Fix this by: (1) Add a new list_add_tail_release() function that uses a release barrier to set the pointer to the new member of the list. (2) Add a new list_first_entry_or_null_acquire() function that uses an acquire barrier to read the pointer to the first member in a list (or return NULL). (3) Use list_add_tail_release() when adding a subreq to ->subrequests. (4) Use list_first_entry_or_null_acquire() when initially accessing the front of the list (when an item is removed, the pointer to the new front iterm is obtained under the same lock).

References

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