Description

In the Linux kernel, the following vulnerability has been resolved:

mptcp: pm: fix UaF read in mptcp_pm_nl_rm_addr_or_subflow

Syzkaller reported this splat:

==================================================================
BUG: KASAN: slab-use-after-free in mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881
Read of size 4 at addr ffff8880569ac858 by task syz.1.2799/14662

CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 Not tainted 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:

__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881
mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [inline]
mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572
mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603
genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/net...

Classification

CVE ID: CVE-2024-50085

CVSS Base Severity: LOW

CVSS Base Score: 0.0

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/35301636439138b821f1f6169bd00d348ebd388a
https://git.kernel.org/stable/c/da3343bc0839b180fd9af9c27fa456d8231409f9
https://git.kernel.org/stable/c/7b2e478abab0b3a33515433a6af563aebba773c1
https://git.kernel.org/stable/c/a8c36ea4ef9a350816f6556c5c5b63810f84b538
https://git.kernel.org/stable/c/7decd1f5904a489d3ccdcf131972f94645681689

Timeline