Li Nan c2925cd620 efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare ... [ Upstream commit a6358f8cf64850f3f27857b8ed8c1b08cfc4685c ] Observed on kernel 6.6 (present on master as well): BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0 Call trace: kasan_check_range+0xe8/0x190 __asan_loadN+0x1c/0x28 memcmp+0x98/0xd0 efivarfs_d_compare+0x68/0xd8 __d_lookup_rcu_op_compare+0x178/0x218 __d_lookup_rcu+0x1f8/0x228 d_alloc_parallel+0x150/0x648 lookup_open.isra.0+0x5f0/0x8d0 open_last_lookups+0x264/0x828 path_openat+0x130/0x3f8 do_filp_open+0x114/0x248 do_sys_openat2+0x340/0x3c0 __arm64_sys_openat+0x120/0x1a0 If dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become negative, leadings to oob. The issue can be triggered by parallel lookups using invalid filename: T1 T2 lookup_open ->lookup simple_lookup d_add // invalid dentry is added to hash list lookup_open d_alloc_parallel __d_lookup_rcu __d_lookup_rcu_op_compare hlist_bl_for_each_entry_rcu // invalid dentry can be retrieved ->d_compare efivarfs_d_compare // oob Fix it by checking 'guid' before cmp. Fixes: da27a24383 ("efivarfs: guid part of filenames are case-insensitive") Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Wu Guanghao <wuguanghao3@huawei.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2025-09-04 15:31:52 +02:00
..
file.c	[tree-wide] finally take no_llseek out	2024-09-27 08:18:43 -07:00
inode.c	efivarfs: Fix error on non-existent file	2024-12-27 14:02:07 +01:00
internal.h	efivarfs: Fix error on non-existent file	2024-12-27 14:02:07 +01:00
Kconfig
Makefile	efi: vars: Move efivar caching layer into efivarfs	2022-06-24 20:40:19 +02:00
super.c	efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare	2025-09-04 15:31:52 +02:00
vars.c	efi: Clear up misconceptions about a maximum variable name size	2024-04-13 10:33:02 +02:00