{"id":"CVE-2021-46992","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nftables: avoid overflows in nft_hash_buckets()\n\nNumber of buckets being stored in 32bit variables, we have to\nensure that no overflows occur in nft_hash_buc…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nftables: avoid overflows in nft_hash_buckets()\n\nNumber of buckets being stored in 32bit variables, we have to\nensure that no overflows occur in nft_hash_buc…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-125"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.9, < 4.14.233","linux_kernel >= 4.15, < 4.19.191","linux_kernel >= 4.20, < 5.4.120","linux_kernel >= 5.5, < 5.10.38","linux_kernel >= 5.11, < 5.11.22","linux_kernel >= 5.12, < 5.12.5"],"patched":["linux_kernel 5.12.5"],"published":"2024-02-28","updated":"2026-08-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-46992","references":[{"url":"https://git.kernel.org/stable/c/1e8ab479cfbe5751efccedb95afb9b112a5ba475","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2824cafc6a93792d9ad85939c499161214d84c4b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/72b49dd116ca00a46a11d5a4d8d7987f05ed9cd7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a388d10961ff8578b1a6691945d406c0f33aa71b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a54754ec9891830ba548e2010c889e3c8146e449","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c77e2ef18167ad334e27610ced9a7f6af5ec1787","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/efcd730ddd6f25578bd31bfe703e593e2421d708","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1e8ab479cfbe5751efccedb95afb9b112a5ba475","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/2824cafc6a93792d9ad85939c499161214d84c4b","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/72b49dd116ca00a46a11d5a4d8d7987f05ed9cd7","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a388d10961ff8578b1a6691945d406c0f33aa71b","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a54754ec9891830ba548e2010c889e3c8146e449","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/c77e2ef18167ad334e27610ced9a7f6af5ec1787","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/efcd730ddd6f25578bd31bfe703e593e2421d708","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00261,"epssPercentile":0.18128,"ingestedAt":"2026-08-04T10:39:38.911Z","slug":"CVE-2021-46992","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nftables: avoid overflows in nft_hash_buckets()\n\nNumber of buckets being stored in 32bit variables, we have to\nensure that no overflows occur in nft_hash_buckets()\n\nsyzbot injected a size == 0x40000000 and reported:\n\nUBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13\nshift exponent 64 is too large for 64-bit type 'long unsigned int'\nCPU: 1 PID: 29539 Comm: syz-executor.4 Not tainted 5.12.0-rc7-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n __dump_stack lib/dump_stack.c:79 [inline]\n dump_stack+0x141/0x1d7 lib/dump_stack.c:120\n ubsan_epilogue+0xb/0x5a lib/ubsan.c:148\n __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327\n __roundup_pow_of_two include/linux/log2.h:57 [inline]\n nft_hash_buckets net/netfilter/nft_set_hash.c:411 [inline]\n nft_hash_estimate.cold+0x19/0x1e net/netfilter/nft_set_hash.c:652\n nft_select_set_ops net/netfilter/nf_tables_api.c:3586 [inline]\n nf_tables_newset+0xe62/0x3110 net/netfilter/nf_tables_api.c:4322\n nfnetlink_rcv_batch+0xa09/0x24b0 net/netfilter/nfnetlink.c:488\n nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:612 [inline]\n nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:630\n netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]\n netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338\n netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927\n sock_sendmsg_nosec net/socket.c:654 [inline]\n sock_sendmsg+0xcf/0x120 net/socket.c:674\n ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350\n ___sys_sendmsg+0xf3/0x170 net/socket.c:2404\n __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n\n## Affected\n\n- `linux_kernel >= 4.9, < 4.14.233`\n- `linux_kernel >= 4.15, < 4.19.191`\n- `linux_kernel >= 4.20, < 5.4.120`\n- `linux_kernel >= 5.5, < 5.10.38`\n- `linux_kernel >= 5.11, < 5.11.22`\n- `linux_kernel >= 5.12, < 5.12.5`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.12.5`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}