CVE-2021-46992

netfilter: nftables: avoid overflows in nft_hash_buckets()

HIGH
7.1
CVSS Score
Published: February 28, 2024 at 08:13 AM UTC
Updated: August 5, 2026 at 09:24 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nftables: avoid overflows in nft_hash_buckets() Number of buckets being stored in 32bit variables, we have to ensure that no overflows occur in nft_hash_buckets() syzbot injected a size == 0x40000000 and reported: UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 shift exponent 64 is too large for 64-bit type 'long unsigned int' CPU: 1 PID: 29539 Comm: syz-executor.4 Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327 __roundup_pow_of_two include/linux/log2.h:57 [inline] nft_hash_buckets net/netfilter/nft_set_hash.c:411 [inline] nft_hash_estimate.cold+0x19/0x1e net/netfilter/nft_set_hash.c:652 nft_select_set_ops net/netfilter/nf_tables_api.c:3586 [inline] nf_tables_newset+0xe62/0x3110 net/netfilter/nf_tables_api.c:4322 nfnetlink_rcv_batch+0xa09/0x24b0 net/netfilter/nfnetlink.c:488 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:612 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:630 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.15 ≤ v < 4.19.1914.20 ≤ v < 5.4.1204.9 ≤ v < 4.14.2334.9 ≤ v < 4.19.1914.9 ≤ v < 5.10.384.9 ≤ v < 5.11.224.9 ≤ v < 5.12.54.9 ≤ v < 5.134.9 ≤ v < 5.4.1205.11 ≤ v < 5.11.225.12 ≤ v < 5.12.55.5 ≤ v < 5.10.380ed6389c483dc77cdbdd48de0ca7ce41723dd6674.9
Vendor states this is fixed in 1e8ab479cfbe5751efccedb95afb9b112a5ba475 (fixed)
Vendor states this is fixed in 2824cafc6a93792d9ad85939c499161214d84c4b (fixed)
Vendor states this is fixed in 72b49dd116ca00a46a11d5a4d8d7987f05ed9cd7 (fixed)
Vendor states this is fixed in a388d10961ff8578b1a6691945d406c0f33aa71b (fixed)
Vendor states this is fixed in a54754ec9891830ba548e2010c889e3c8146e449 (fixed)
Vendor states this is fixed in c77e2ef18167ad334e27610ced9a7f6af5ec1787 (fixed)
Vendor states this is fixed in efcd730ddd6f25578bd31bfe703e593e2421d708 (fixed)
Vendor states this is fixed in 4.14.233 (unaffected)
Vendor states this is fixed in 4.19.191 (unaffected)
Vendor states this is fixed in 4.9 (unaffected)
Vendor states this is fixed in 5.10.38 (unaffected)
Vendor states this is fixed in 5.11.22 (unaffected)
Vendor states this is fixed in 5.12.5 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.4.120 (unaffected)

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1e8ab479cfbe5751efccedb95afb9b112a5ba475
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2824cafc6a93792d9ad85939c499161214d84c4b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/72b49dd116ca00a46a11d5a4d8d7987f05ed9cd7
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/a388d10961ff8578b1a6691945d406c0f33aa71b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/a54754ec9891830ba548e2010c889e3c8146e449
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c77e2ef18167ad334e27610ced9a7f6af5ec1787
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/efcd730ddd6f25578bd31bfe703e593e2421d708

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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