diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-06-10 22:19:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-16 20:44:52 +0300 |
| commit | f08db490b4069f64a2fd700f9ebd0f62d49dffc4 (patch) | |
| tree | ab7160bdbcb37404e745ceca228b5e912d525002 /net/core | |
| parent | 0b7d9b8571ad1542034db38911418697005a3225 (diff) | |
| download | linux-f08db490b4069f64a2fd700f9ebd0f62d49dffc4.tar.xz | |
bpf: reject wrong sized filters earlier
commit f7bd9e36ee4a4ce38e1cddd7effe6c0d9943285b upstream.
Add a bpf_check_basics_ok() and reject filters that are of invalid
size much earlier, so we don't do any useless work such as invoking
bpf_prog_alloc(). Currently, rejection happens in bpf_check_classic()
only, but it's really unnecessarily late and they should be rejected
at earliest point. While at it, also clean up one bpf_prog_size() to
make it consistent with the remaining invocations.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 1a9ded6af138..3c5f51198c41 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -742,6 +742,17 @@ static bool chk_code_allowed(u16 code_to_probe) return codes[code_to_probe]; } +static bool bpf_check_basics_ok(const struct sock_filter *filter, + unsigned int flen) +{ + if (filter == NULL) + return false; + if (flen == 0 || flen > BPF_MAXINSNS) + return false; + + return true; +} + /** * bpf_check_classic - verify socket filter code * @filter: filter to verify @@ -762,9 +773,6 @@ static int bpf_check_classic(const struct sock_filter *filter, bool anc_found; int pc; - if (flen == 0 || flen > BPF_MAXINSNS) - return -EINVAL; - /* Check the filter code now */ for (pc = 0; pc < flen; pc++) { const struct sock_filter *ftest = &filter[pc]; @@ -1057,7 +1065,7 @@ int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog) struct bpf_prog *fp; /* Make sure new filter is there and in the right amounts. */ - if (fprog->filter == NULL) + if (!bpf_check_basics_ok(fprog->filter, fprog->len)) return -EINVAL; fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); @@ -1104,7 +1112,7 @@ int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, int err; /* Make sure new filter is there and in the right amounts. */ - if (fprog->filter == NULL) + if (!bpf_check_basics_ok(fprog->filter, fprog->len)) return -EINVAL; fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); @@ -1184,7 +1192,6 @@ int __sk_attach_filter(struct sock_fprog *fprog, struct sock *sk, bool locked) { unsigned int fsize = bpf_classic_proglen(fprog); - unsigned int bpf_fsize = bpf_prog_size(fprog->len); struct bpf_prog *prog; int err; @@ -1192,10 +1199,10 @@ int __sk_attach_filter(struct sock_fprog *fprog, struct sock *sk, return -EPERM; /* Make sure new filter is there and in the right amounts. */ - if (fprog->filter == NULL) + if (!bpf_check_basics_ok(fprog->filter, fprog->len)) return -EINVAL; - prog = bpf_prog_alloc(bpf_fsize, 0); + prog = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); if (!prog) return -ENOMEM; |