Уязвимость функции bond_option_arp_ip_targets_set() сетевой компоненты ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность и доступность защищаемой информации

In the Linux kernel, the following vulnerability has been resolved: bonding: Fix out-of-bounds read in bond_option_arp_ip_targets_set() In function bond_option_arp_ip_targets_set(), if newval->string is an empty string, newval->string+1 will point to the byte after the string, causing an out-of-bound read. BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418 Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107 CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc1/0x5e0 mm/kasan/report.c:475 kasan_report+0xbe/0xf0 mm/kasan/report.c:588 strlen+0x7d/0xa0 lib/string.c:418 __fortify_strlen include/linux/fortify-string.h:210 [inline] in4_pton+0xa3/0x3f0 net/core/utils.c:130 bond_option_arp_ip_targets_set+0xc2/0x910 drivers/net/bonding/bond_options.c:1201 __bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767 __bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792 bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817 bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156 dev_attr_store+0x54/0x80 drivers/base/core.c:2366 sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x96a/0xd80 fs/read_write.c:584 ksys_write+0x122/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b ---[ end trace ]--- Fix it by adding a check of string length before using it.

In the Linux kernel, the following vulnerability has been resolved: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so trying to fix one possible overflow is just moot.