Tatsuhiko Yasumatsu b14f28126c bpf: Fix integer overflow in prealloc_elems_and_freelist() ... [ Upstream commit 30e29a9a2bc6a4888335a6ede968b75cd329657a ] In prealloc_elems_and_freelist(), the multiplication to calculate the size passed to bpf_map_area_alloc() could lead to an integer overflow. As a result, out-of-bounds write could occur in pcpu_freelist_populate() as reported by KASAN: [...] [ 16.968613] BUG: KASAN: slab-out-of-bounds in pcpu_freelist_populate+0xd9/0x100 [ 16.969408] Write of size 8 at addr ffff888104fc6ea0 by task crash/78 [ 16.970038] [ 16.970195] CPU: 0 PID: 78 Comm: crash Not tainted 5.15.0-rc2+ #1 [ 16.970878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 16.972026] Call Trace: [ 16.972306] dump_stack_lvl+0x34/0x44 [ 16.972687] print_address_description.constprop.0+0x21/0x140 [ 16.973297] ? pcpu_freelist_populate+0xd9/0x100 [ 16.973777] ? pcpu_freelist_populate+0xd9/0x100 [ 16.974257] kasan_report.cold+0x7f/0x11b [ 16.974681] ? pcpu_freelist_populate+0xd9/0x100 [ 16.975190] pcpu_freelist_populate+0xd9/0x100 [ 16.975669] stack_map_alloc+0x209/0x2a0 [ 16.976106] __sys_bpf+0xd83/0x2ce0 [...] The possibility of this overflow was originally discussed in [0], but was overlooked. Fix the integer overflow by changing elem_size to u64 from u32. [0] https://lore.kernel.org/bpf/728b238e-a481-eb50-98e9-b0f430ab01e7@gmail.com/ Fixes: 557c0c6e7d ("bpf: convert stackmap to pre-allocation") Signed-off-by: Tatsuhiko Yasumatsu <th.yasumatsu@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210930135545.173698-1-th.yasumatsu@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-10-13 10:08:18 +02:00
..
arraymap.c
bpf_lru_list.c	bpf_lru_list: Read double-checked variable once without lock	2021-03-04 10:26:16 +01:00
bpf_lru_list.h
btf.c
cgroup.c
core.c	bpf: Introduce BPF nospec instruction for mitigating Spectre v4	2021-09-15 09:47:38 +02:00
cpumap.c
devmap.c
disasm.c	bpf: Introduce BPF nospec instruction for mitigating Spectre v4	2021-09-15 09:47:38 +02:00
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 integer overflow in prealloc_elems_and_freelist()	2021-10-13 10:08:18 +02:00
syscall.c
sysfs_btf.c
tnum.c
verifier.c	bpf: Add oversize check before call kvcalloc()	2021-09-30 10:09:25 +02:00
xskmap.c