CVE-2024-26805

CVE Details

Release Date:

2024-04-04

Description

In the Linux kernel, the following vulnerability has been resolved:\nnetlink: Fix kernel-infoleak-after-free in __skb_datagram_iter\nsyzbot reported the following uninit-value access issue [1]:\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.\nThis patch resolved this issue by correct the len from `skb->end` to\n`skb->len`, which is the actual data offset.\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\ninstrument_copy_to_user include/linux/instrumented.h:114 [inline]\ncopy_to_user_iter lib/iov_iter.c:24 [inline]\niterate_ubuf include/linux/iov_iter.h:29 [inline]\niterate_and_advance2 include/linux/iov_iter.h:245 [inline]\niterate_and_advance include/linux/iov_iter.h:271 [inline]\n_copy_to_iter+0x364/0x2520 lib/iov_iter.c:186\ncopy_to_iter include/linux/uio.h:197 [inline]\nsimple_copy_to_iter+0x68/0xa0 net/core/datagram.c:532\n__skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:420\nskb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546\nskb_copy_datagram_msg include/linux/skbuff.h:3960 [inline]\npacket_recvmsg+0xd9c/0x2000 net/packet/af_packet.c:3482\nsock_recvmsg_nosec net/socket.c:1044 [inline]\nsock_recvmsg net/socket.c:1066 [inline]\nsock_read_iter+0x467/0x580 net/socket.c:1136\ncall_read_iter include/linux/fs.h:2014 [inline]\nnew_sync_read fs/read_write.c:389 [inline]\nvfs_read+0x8f6/0xe00 fs/read_write.c:470\nksys_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\ndo_syscall_x64 arch/x86/entry/common.c:52 [inline]\ndo_syscall_64+0x44/0x110 arch/x86/entry/common.c:83\nentry_SYSCALL_64_after_hwframe+0x63/0x6b\nUninit was stored to memory at:\nskb_put_data include/linux/skbuff.h:2622 [inline]\nnetlink_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\nnetlink_deliver_tap net/netlink/af_netlink.c:338 [inline]\nnetlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline]\nnetlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]\nnetlink_unicast+0x10f1/0x1250 net/netlink/af_netlink.c:1368\nnetlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910\nsock_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\ndo_syscall_x64 arch/x86/entry/common.c:52 [inline]\ndo_syscall_64+0x44/0x110 arch/x86/entry/common.c:83\nentry_SYSCALL_64_after_hwframe+0x63/0x6b\nUninit was created at:\nfree_pages_prepare mm/page_alloc.c:1087 [inline]\nfree_unref_page_prepare+0xb0/0xa40 mm/page_alloc.c:2347\nfree_unref_page_list+0xeb/0x1100 mm/page_alloc.c:2533\nrelease_pages+0x23d3/0x2410 mm/swap.c:1042\nfree_pages_and_swap_cache+0xd9/0xf0 mm/swap_state.c:316\ntlb_batch_pages\n---truncated---

See more information about CVE-2024-26805 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	5.5	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	Low	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 6 (kernel-uek)	ELSA-2024-12606	2024-09-02
Oracle Linux version 7 (kernel-uek)	ELSA-2024-12606	2024-09-02
Oracle VM version 3 (kernel-uek)	OVMSA-2024-0011	2024-09-03