{"cve":"CVE-2024-26805","nvd":{"published":"2024-04-04T09:15:09.277","modified":"2026-10-15T01:17:23.813","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetlink: Fix kernel-infoleak-after-free in __skb_datagram_iter\n\nsyzbot reported the following uninit-value access issue [1]:\n\nnetlink_to_full_skb() creates a new `skb` and puts the `skb->data`\npassed as a 1st arg of netlink_to_full_skb() onto new `skb`. The data\nsize is specified as `len` and passed to skb_put_data(). This `len`\nis based on `skb->end` that is not data offset but buffer offset. The\n`skb->end` contains data and tailroom. Since the tailroom is not\ninitialized when the new `skb` created, KMSAN detects uninitialized\nmemory area when copying the data.\n\nThis patch resolved this issue by correct the len from `skb->end` to\n`skb->len`, which is the actual data offset.\n\nBUG: KMSAN: kernel-infoleak-after-free in instrument_copy_to_user include/linux/instrumented.h:114 [inline]\nBUG: KMSAN: kernel-infoleak-after-free in copy_to_user_iter lib/iov_iter.c:24 [inline]\nBUG: KMSAN: kernel-infoleak-after-free in iterate_ubuf include/linux/iov_iter.h:29 [inline]\nBUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\nBUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance include/linux/iov_iter.h:271 [inline]\nBUG: KMSAN: kernel-infoleak-after-free in _copy_to_iter+0x364/0x2520 lib/iov_iter.c:186\n instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n copy_to_user_iter lib/iov_iter.c:24 [inline]\n iterate_ubuf include/linux/iov_iter.h:29 [inline]\n iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\n iterate_and_advance include/linux/iov_iter.h:271 [inline]\n _copy_to_iter+0x364/0x2520 lib/iov_iter.c:186\n copy_to_iter include/linux/uio.h:197 [inline]\n simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:532\n __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:420\n skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546\n skb_copy_datagram_msg include/linux/skbuff.h:3960 [inline]\n packet_recvmsg+0xd9c/0x2000 net/packet/af_packet.c:3482\n sock_recvmsg_nosec net/socket.c:1044 [inline]\n sock_recvmsg net/socket.c:1066 [inline]\n sock_read_iter+0x467/0x580 net/socket.c:1136\n call_read_iter include/linux/fs.h:2014 [inline]\n new_sync_read fs/read_write.c:389 [inline]\n vfs_read+0x8f6/0xe00 fs/read_write.c:470\n ksys_read+0x20f/0x4c0 fs/read_write.c:613\n __do_sys_read fs/read_write.c:623 [inline]\n __se_sys_read fs/read_write.c:621 [inline]\n __x64_sys_read+0x93/0xd0 fs/read_write.c:621\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nUninit was stored to memory at:\n skb_put_data include/linux/skbuff.h:2622 [inline]\n netlink_to_full_skb net/netlink/af_netlink.c:181 [inline]\n __netlink_deliver_tap_skb net/netlink/af_netlink.c:298 [inline]\n __netlink_deliver_tap+0x5be/0xc90 net/netlink/af_netlink.c:325\n netlink_deliver_tap net/netlink/af_netlink.c:338 [inline]\n netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline]\n netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]\n netlink_unicast+0x10f1/0x1250 net/netlink/af_netlink.c:1368\n netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg net/socket.c:745 [inline]\n ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584\n ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638\n __sys_sendmsg net/socket.c:2667 [inline]\n __do_sys_sendmsg net/socket.c:2676 [inline]\n __se_sys_sendmsg net/socket.c:2674 [inline]\n __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nUninit was created at:\n free_pages_prepare mm/page_alloc.c:1087 [inline]\n free_unref_page_prepare+0xb0/0xa40 mm/page_alloc.c:2347\n free_unref_page_list+0xeb/0x1100 mm/page_alloc.c:2533\n release_pages+0x23d3/0x2410 mm/swap.c:1042\n free_pages_and_swap_cache+0xd9/0xf0 mm/swap_state.c:316\n tlb_batch_pages\n---truncated---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/0b27bf4c494d61e5663baa34c3edd7ccebf0ea44","https://git.kernel.org/stable/c/59fc3e3d049e39e7d0d271f20dd5fb47c57faf1d","https://git.kernel.org/stable/c/661779e1fcafe1b74b3f3fe8e980c1e207fea1fd","https://git.kernel.org/stable/c/9ae51361da43270f4ba0eb924427a07e87e48777","https://git.kernel.org/stable/c/c71ed29d15b1a1ed6c464f8c3536996963046285"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:48:32.179249784+00:00"},"epss":{"cve":"CVE-2024-26805","score":0.00242,"percentile":0.15224,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}