# CVE-2021-46915: linux: In the Linux kernel, the following vulnerability has been resolved:  netfilter: nft_limit: avoid possible divide erro...

CVE-2021-46915 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-46915, released February 27, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-46915
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 27, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  netfilter: nft_limit: avoid possible divide error in nft_limit_init  div_u64() divides u64 by u32.  nft_limit_init() wants to divide u64 by u64, use the appropriate math function (div64_u64)  divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8390 Comm: syz-executor188 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:div_u64_rem include/linux/math64.h:28 [inline] RIP: 0010:div_u64 include/linux/math64.h:127 [inline] RIP: 0010:nft_limit_init+0x2a2/0x5e0 net/netfilter/nft_limit.c:85 Code: ef 4c 01 eb 41 0f 92 c7 48 89 de e8 38 a5 22 fa 4d 85 ff 0f 85 97 02 00 00 e8 ea 9e 22 fa 4c 0f af f3 45 89 ed 31 d2 4c 89 f0 <49> f7 f5 49 89 c6 e8 d3 9e 22 fa 48 8d 7d 48 48 b8 00 00 00 00 00 RSP: 0018:ffffc90009447198 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000200000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff875152e6 RDI: 0000000000000003 RBP: ffff888020f80908 R08: 0000200000000000 R09: 0000000000000000 R10: ffffffff875152d8 R11: 0000000000000000 R12: ffffc90009447270 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS:  000000000097a300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c4 CR3: 0000000026a52000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace:  nf_tables_newexpr net/netfilter/nf_tables_api.c:2675 [inline]  nft_expr_init+0x145/0x2d0 net/netfilter/nf_tables_api.c:2713  nft_set_elem_expr_alloc+0x27/0x280 net/netfilter/nf_tables_api.c:5160  nf_tables_newset+0x1997/0x3150 net/netfilter/nf_tables_api.c:4321  nfnetlink_rcv_batch+0x85a/0x21b0 net/netfilter/nfnetlink.c:456  nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:580 [inline]  nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:598  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  entry_SYSCALL_64_after_hwframe+0x44/0xae

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.10.38-1 | [DEBIAN-CVE-2021-46915](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46915.md) | Feb 27, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.10.38-1 | [DEBIAN-CVE-2021-46915](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46915.md) | Feb 27, 2024 |
| Linux | linux Debian 14 | 5.10.38-1 | [DEBIAN-CVE-2021-46915](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46915.md) | Feb 27, 2024 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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