# CVE-2023-53133: linux: In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix an infinite loop error when le... CVE-2023-53133 is fixed in 20 products on 1 platform, first by ALAS2023-2023-148, released March 30, 2023. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2023-53133 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0019 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Mar 30, 2023 ## Description In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() When the buffer length of the recvmsg system call is 0, we got the flollowing soft lockup problem: watchdog: BUG: soft lockup - CPU#3 stuck for 27s! [a.out:6149] CPU: 3 PID: 6149 Comm: a.out Kdump: loaded Not tainted 6.2.0+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:remove_wait_queue+0xb/0xc0 Code: 5e 41 5f c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 48 89 fd 53 48 89 f3 4c 8d 6b 18 4c 8d 73 20 RSP: 0018:ffff88811b5978b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88811a7d3780 RCX: ffffffffb7a4d768 RDX: dffffc0000000000 RSI: ffff88811b597908 RDI: ffff888115408040 RBP: 1ffff110236b2f1b R08: 0000000000000000 R09: ffff88811a7d37e7 R10: ffffed10234fa6fc R11: 0000000000000001 R12: ffff88811179b800 R13: 0000000000000001 R14: ffff88811a7d38a8 R15: ffff88811a7d37e0 FS: 00007f6fb5398740(0000) GS:ffff888237180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 000000010b6ba002 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_msg_wait_data+0x279/0x2f0 tcp_bpf_recvmsg_parser+0x3c6/0x490 inet_recvmsg+0x280/0x290 sock_recvmsg+0xfc/0x120 ____sys_recvmsg+0x160/0x3d0 ___sys_recvmsg+0xf0/0x180 __sys_recvmsg+0xea/0x1a0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc The logic in tcp_bpf_recvmsg_parser is as follows: msg_bytes_ready: copied = sk_msg_recvmsg(sk, psock, msg, len, flags); if (!copied) { wait data; goto msg_bytes_ready; } In this case, "copied" always is 0, the infinite loop occurs. According to the Linux system call man page, 0 should be returned in this case. Therefore, in tcp_bpf_recvmsg_parser(), if the length is 0, directly return. Also modify several other functions with the same problem. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | bpftool-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-headers amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf-static amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-livepatch-6.1.21-1.45 amzn 2023 | 1.0-0.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | linux Debian 12.15 (bookworm) | 6.1.20-1 | [DEBIAN-CVE-2023-53133](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53133.md) | May 2, 2025 | | Linux | linux Debian 13.5 (trixie) | 6.1.20-1 | [DEBIAN-CVE-2023-53133](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53133.md) | May 2, 2025 | | Linux | linux Debian 14 | 6.1.20-1 | [DEBIAN-CVE-2023-53133](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53133.md) | May 2, 2025 | | Linux | perf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | perf-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | python3-perf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | python3-perf-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | --- Data as of 2026-11-08T13:06:02Z UTC. 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