جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: net: bonding: fix use-after-free after 802.3ad slave unbind commit 0622cab0341c ("bonding: fix 802.3ad aggregator reselection"), resolve case, when there is several aggregation groups in the same bond. bond_3ad_unbind_slave will invalidate (clear) aggregator when __agg_active_ports return zero. So, ad_clear_agg can be executed even, when num_of_ports!=0. Than bond_3ad_unbind_slave can be executed again for, previously cleared aggregator. NOTE: at this time bond_3ad_unbind_slave will not update slave ports list, because lag_ports==NULL. So, here we got slave ports, pointing to freed aggregator memory. Fix with checking actual number of ports in group (as was before commit 0622cab0341c ("bonding: fix 802.3ad aggregator reselection") ), before ad_clear_agg(). The KASAN logs are as follows: [ 767.617392] ================================================================== [ 767.630776] BUG: KASAN: use-after-free in bond_3ad_state_machine_handler+0x13dc/0x1470 [ 767.638764] Read of size 2 at addr ffff00011ba9d430 by task kworker/u8:7/767 [ 767.647361] CPU: 3 PID: 767 Comm: kworker/u8:7 Tainted: G O 5.15.11 #15 [ 767.655329] Hardware name: DNI AmazonGo1 A7040 board (DT) [ 767.660760] Workqueue: lacp_1 bond_3ad_state_machine_handler [ 767.666468] Call trace: [ 767.668930] dump_backtrace+0x0/0x2d0 [ 767.672625] show_stack+0x24/0x30 [ 767.675965] dump_stack_lvl+0x68/0x84 [ 767.679659] print_address_description.constprop.0+0x74/0x2b8 [ 767.685451] kasan_report+0x1f0/0x260 [ 767.689148] __asan_load2+0x94/0xd0 [ 767.692667] bond_3ad_state_machine_handler+0x13dc/0x1470

• https://git.kernel.org/stable/c/a853b7a3a9fd1d74a4ccdd9cd73512b7dace2f1e
• https://git.kernel.org/stable/c/b90ac60303063a43e17dd4aec159067599d255e6
• https://git.kernel.org/stable/c/f162f7c348fa2a5555bafdb5cc890b89b221e69c
• https://git.kernel.org/stable/c/893825289ba840afd86bfffcb6f7f363c73efff8
• https://git.kernel.org/stable/c/63b2fe509f69b90168a75e04e14573dccf7984e6
• https://git.kernel.org/stable/c/ef0af7d08d26c5333ff4944a559279464edf6f15
• https://git.kernel.org/stable/c/2765749def4765c5052a4c66445cf4c96fcccdbc
• https://git.kernel.org/stable/c/050133e1aa2cb49bb17be847d48a4431598ef562