kernel_samsung_a53x/kernel/bpf
Toke Høiland-Jørgensen b978ef4744 bpf: Fix DEVMAP_HASH overflow check on 32-bit arches
[ Upstream commit 281d464a34f540de166cee74b723e97ac2515ec3 ]

The devmap code allocates a number hash buckets equal to the next power
of two of the max_entries value provided when creating the map. When
rounding up to the next power of two, the 32-bit variable storing the
number of buckets can overflow, and the code checks for overflow by
checking if the truncated 32-bit value is equal to 0. However, on 32-bit
arches the rounding up itself can overflow mid-way through, because it
ends up doing a left-shift of 32 bits on an unsigned long value. If the
size of an unsigned long is four bytes, this is undefined behaviour, so
there is no guarantee that we'll end up with a nice and tidy 0-value at
the end.

Syzbot managed to turn this into a crash on arm32 by creating a
DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it.
Fix this by moving the overflow check to before the rounding up
operation.

Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Link: https://lore.kernel.org/r/000000000000ed666a0611af6818@google.com
Reported-and-tested-by: syzbot+8cd36f6b65f3cafd400a@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Message-ID: <20240307120340.99577-2-toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 08:44:48 +01:00
..
preload Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
arraymap.c bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2024-11-18 12:13:12 +01:00
bpf_inode_storage.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_iter.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_local_storage.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_lru_list.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_lru_list.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_lsm.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_struct_ops.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bpf_struct_ops_types.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
btf.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cgroup.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
core.c bpf: Detect IP == ksym.end as part of BPF program 2024-11-18 11:43:12 +01:00
cpumap.c cpumap: Zero-initialise xdp_rxq_info struct before running XDP program 2024-11-18 23:19:34 +01:00
devmap.c bpf: Fix DEVMAP_HASH overflow check on 32-bit arches 2024-11-19 08:44:48 +01:00
disasm.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
disasm.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
dispatcher.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
hashtab.c bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2024-11-18 12:13:12 +01:00
helpers.c bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctly 2024-11-19 08:44:44 +01:00
inode.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
local_storage.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
lpm_trie.c bpf, lpm: Fix check prefixlen before walking trie 2024-11-18 12:12:28 +01:00
Makefile Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
map_in_map.c bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2024-11-18 12:13:12 +01:00
map_in_map.h bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2024-11-18 12:13:12 +01:00
map_iter.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
net_namespace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
offload.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
percpu_freelist.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
percpu_freelist.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
prog_iter.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
queue_stack_maps.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
reuseport_array.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
ringbuf.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stackmap.c bpf: Add crosstask check to __bpf_get_stack 2024-11-18 12:12:28 +01:00
syscall.c bpf: Set uattr->batch.count as zero before batched update or deletion 2024-11-18 12:13:12 +01:00
sysfs_btf.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
task_iter.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
tnum.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
trampoline.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
verifier.c bpf: Fix verification of indirect var-off stack access 2024-11-18 12:12:36 +01:00