Messages in this thread Patch in this message | | | Date | Fri, 9 Aug 2019 20:26:22 +0200 | From | Paul Chaignon <> | Subject | [PATCH] seccomp: allow BPF_MOD ALU instructions |
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We need BPF_MOD to match system calls against whitelists encoded as 32-bit bit arrays. The selection of the syscall's bit in the appropriate bit array requires a modulo operation such that X = 1 << nr % 32.
Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> --- kernel/seccomp.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 811b4a86cdf6..87de6532ff6d 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -205,6 +205,8 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) case BPF_ALU | BPF_MUL | BPF_X: case BPF_ALU | BPF_DIV | BPF_K: case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU | BPF_MOD | BPF_K: + case BPF_ALU | BPF_MOD | BPF_X: case BPF_ALU | BPF_AND | BPF_K: case BPF_ALU | BPF_AND | BPF_X: case BPF_ALU | BPF_OR | BPF_K: -- 2.17.1
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