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authorAnton Protopopov <a.s.protopopov@gmail.com>2020-05-27 20:56:59 +0200
committerAlexei Starovoitov <ast@kernel.org>2020-06-01 23:38:21 +0200
commit1ea0f9120c8ce105ca181b070561df5cbd6bc049 (patch)
tree7e4c0c652d27f92872fc680e3dd06fb67548ec75 /kernel/bpf
parentselftests/bpf: Cleanup comments in test_maps (diff)
downloadlinux-1ea0f9120c8ce105ca181b070561df5cbd6bc049.tar.xz
linux-1ea0f9120c8ce105ca181b070561df5cbd6bc049.zip
bpf: Fix map permissions check
The map_lookup_and_delete_elem() function should check for both FMODE_CAN_WRITE and FMODE_CAN_READ permissions because it returns a map element to user space. Fixes: bd513cd08f10 ("bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscall") Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200527185700.14658-5-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/syscall.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index d13b804ff045..2c969a9b90d3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1472,7 +1472,8 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
- if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+ if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
+ !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}