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authorArnd Bergmann <arnd@arndb.de>2017-11-02 14:05:52 +0300
committerDavid S. Miller <davem@davemloft.net>2017-11-03 08:20:22 +0300
commiteba0c929d1d0f16c4b03628b7bf8ce363b9e5c9a (patch)
tree31b61a4bf69c68a925ffedd626ab3fef0c9b0ba2 /kernel/bpf
parent7cce782ef32f5003c18ab8f9f586f2ed5ce2c33e (diff)
downloadlinux-eba0c929d1d0f16c4b03628b7bf8ce363b9e5c9a.tar.xz
bpf: fix out-of-bounds access warning in bpf_check
The bpf_verifer_ops array is generated dynamically and may be empty depending on configuration, which then causes an out of bounds access: kernel/bpf/verifier.c: In function 'bpf_check': kernel/bpf/verifier.c:4320:29: error: array subscript is above array bounds [-Werror=array-bounds] This adds a check to the start of the function as a workaround. I would assume that the function is never called in that configuration, so the warning is probably harmless. Fixes: 00176a34d9e2 ("bpf: remove the verifier ops from program structure") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5f3799dcba01..ab5aa5497666 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4474,6 +4474,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
struct bpf_verifer_log *log;
int ret = -EINVAL;
+ /* no program is valid */
+ if (ARRAY_SIZE(bpf_verifier_ops) == 0)
+ return -EINVAL;
+
/* 'struct bpf_verifier_env' can be global, but since it's not small,
* allocate/free it every time bpf_check() is called
*/