android_kernel_motorola_sm6375/kernel/bpf
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Filename Latest commit message Latest commit date
Will Deacon 120cdad8b2 bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields
commit 0613d8ca9ab382caabe9ed2dceb429e9781e443f upstream.

A narrow load from a 64-bit context field results in a 64-bit load
followed potentially by a 64-bit right-shift and then a bitwise AND
operation to extract the relevant data.

In the case of a 32-bit access, an immediate mask of 0xffffffff is used
to construct a 64-bit BPP_AND operation which then sign-extends the mask
value and effectively acts as a glorified no-op. For example:

0:	61 10 00 00 00 00 00 00	r0 = *(u32 *)(r1 + 0)

results in the following code generation for a 64-bit field:

	ldr	x7, [x7]	// 64-bit load
	mov	x10, #0xffffffffffffffff
	and	x7, x7, x10

Fix the mask generation so that narrow loads always perform a 32-bit AND
operation:

	ldr	x7, [x7]	// 64-bit load
	mov	w10, #0xffffffff
	and	w7, w7, w10

Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
Cc: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Fixes: 31fd85816d ("bpf: permits narrower load from bpf program context fields")
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230518102528.1341-1-will@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30 12:44:10 +01:00
..
arraymap.c
bpf_lru_list.c
bpf_lru_list.h
btf.c btf: fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR 2023-03-17 08:32:51 +01:00
cgroup.c bpf: Don't EFAULT for getsockopt with optval=NULL 2023-05-17 11:35:44 +02:00
core.c bpf: Adjust insufficient default bpf_jit_limit 2023-04-05 11:16:37 +02:00
cpumap.c
devmap.c bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc 2021-12-17 10:12:24 +01:00
disasm.c
disasm.h
hashtab.c
helpers.c
inode.c
local_storage.c
lpm_trie.c
Makefile
map_in_map.c
map_in_map.h
offload.c
percpu_freelist.c
percpu_freelist.h
queue_stack_maps.c
reuseport_array.c
stackmap.c bpf: Fix incorrect memory charge cost calculation in stack_map_alloc() 2022-06-22 14:11:02 +02:00
syscall.c bpf: Ensure correct locking around vulnerable function find_vpid() 2022-10-26 13:22:24 +02:00
sysfs_btf.c
tnum.c
verifier.c bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields 2023-05-30 12:44:10 +01:00
xskmap.c