sctp: fix kernel-infoleak for SCTP sockets

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: fix kernel-infoleak for SCTP sockets syzbot reported a kernel infoleak [1] of 4 bytes. After analysis, it turned out r->idiag_expires is not initialized if inet_sctp_diag_fill() calls inet_diag_msg_common_fill() Make sure to clear idiag_timer/idiag_retrans/idiag_expires and let inet_diag_msg_sctpasoc_fill() fill them again if needed. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:154 [inline] _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 copy_to_iter include/linux/uio.h:162 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline] netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] __sys_recvfrom+0x795/0xa10 net/socket.c:2097 __do_sys_recvfrom net/socket.c:2115 [inline] __se_sys_recvfrom net/socket.c:2111 [inline] __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3247 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] sock_write_iter+0x594/0x690 net/socket.c:1061 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x645/0xe00 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 2508 are uninitialized Memory access of size 2508 starts at ffff888114f9b000 Data copied to user address 00007f7fe09ff2e0 CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Scores

EPSS (exploitation in 30 days)

0.23% · top 86% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.

Weakness

• CWE-401 (opens in a new tab)All about CWE-401 and its CVEs

Affected products

• Linux · Linux

  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < 3fc0fd724d199e061432b66a8d85b7d48fe485f7
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < 41a2864cf719c17294f417726edd411643462ab8
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < 2d8fa3fdf4542a2174a72d92018f488d65d848c5
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < bbf59d7ae558940cfa2b36a287fd1e88d83f89f8
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < b7e4d9ba2ddb78801488b4c623875b81fb46b545
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < 1502f15b9f29c41883a6139f2923523873282a83
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < d828b0fe6631f3ae8709ac9a10c77c5836c76a08
  • affected 8f840e47f190cbe61a96945c13e9551048d42cef – < 633593a808980f82d251d0ca89730d8bb8b0220c

• Linux · Linux

  • affected 4.7
  • unaffected < 4.7
  • unaffected 4.9.307 – ≤ 4.9.*
  • unaffected 4.14.272 – ≤ 4.14.*
  • unaffected 4.19.235 – ≤ 4.19.*
  • unaffected 5.4.185 – ≤ 5.4.*
  • unaffected 5.10.106 – ≤ 5.10.*
  • unaffected 5.15.29 – ≤ 5.15.*
  • unaffected 5.16.15 – ≤ 5.16.*
  • unaffected 5.17 – ≤ *

References (8)

• https://git.kernel.org/stable/c/3fc0fd724d199e061432b66a8d85b7d48fe485f7 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/41a2864cf719c17294f417726edd411643462ab8 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/2d8fa3fdf4542a2174a72d92018f488d65d848c5 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/bbf59d7ae558940cfa2b36a287fd1e88d83f89f8 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/b7e4d9ba2ddb78801488b4c623875b81fb46b545 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/1502f15b9f29c41883a6139f2923523873282a83 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/d828b0fe6631f3ae8709ac9a10c77c5836c76a08 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/633593a808980f82d251d0ca89730d8bb8b0220c (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-48855](https://trackcve.app/badge/CVE-2022-48855.svg)](https://trackcve.app/cve/CVE-2022-48855)

Record last updated 11 May 2026, 18:48 UTC.