wifi: fix leak if split 6 GHz scanning fails

Overview

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

wifi: fix leak if split 6 GHz scanning fails

rdev->int_scan_req is leaked if cfg80211_scan() fails. Note that it's supposed to be released at ___cfg80211_scan_done() but this doesn't happen as rdev->scan_req is NULL at that point, too, leading to the early return from the freeing function.

unreferenced object 0xffff8881161d0800 (size 512): comm "wpa_supplicant", pid 379, jiffies 4294749765 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 f0 81 13 16 81 88 ff ff ................ backtrace (crc c867fdb6): kmemleak_alloc+0x89/0x90 __kmalloc_noprof+0x2fd/0x410 cfg80211_scan+0x133/0x730 nl80211_trigger_scan+0xc69/0x1cc0 genl_family_rcv_msg_doit+0x204/0x2f0 genl_rcv_msg+0x431/0x6b0 netlink_rcv_skb+0x143/0x3f0 genl_rcv+0x27/0x40 netlink_unicast+0x4f6/0x820 netlink_sendmsg+0x797/0xce0 __sock_sendmsg+0xc4/0x160 ____sys_sendmsg+0x5e4/0x890 ___sys_sendmsg+0xf8/0x180 __sys_sendmsg+0x136/0x1e0 __x64_sys_sendmsg+0x76/0xc0 x64_sys_call+0x13f0/0x17d0

Found by Linux Verification Center (linuxtesting.org).

Affected

• Linux >= c8cb5b854b40f2ce52ccd032fa19750f4181d5fc < 87484866cae9130b97c2b356eeaea4f47b292f75
• Linux >= c8cb5b854b40f2ce52ccd032fa19750f4181d5fc < df44397bbd8f3a38115c9590b686787e4aaf6327
• Linux >= c8cb5b854b40f2ce52ccd032fa19750f4181d5fc < fb8db813eba2e56ee001c9fb5c2ce2cb78c42642
• Linux >= c8cb5b854b40f2ce52ccd032fa19750f4181d5fc < a24134ddc18b4d440714365637d440b7121447b9
• Linux >= c8cb5b854b40f2ce52ccd032fa19750f4181d5fc < e8694f7cc29287e843648d1075177b9a2000d957
• Linux 5.10

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.