diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-09-11 20:27:37 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-15 12:05:28 +0200 |
| commit | bcbfd0c0a36147834e337cb76357cadedc822f90 (patch) | |
| tree | 80850a6d165f9d4fba3119bd2b15cfcd8473355a | |
| parent | e39b8b0e9c277722801db9eeab00aa7a0f18dc60 (diff) | |
net: filter: fix possible use after free
[ No appicable upstream commit, this bug has been subsequently been
fixed as a side effect of other changes. ]
If kmemdup() fails, we free fp->orig_prog and return -ENOMEM
sk_attach_filter()
-> sk_filter_uncharge(sk, fp)
-> sk_filter_release(fp)
-> call_rcu(&fp->rcu, sk_filter_release_rcu)
-> sk_filter_release_rcu()
-> sk_release_orig_filter()
fprog = fp->orig_prog; // not NULL, but points to freed memory
kfree(fprog->filter); // use after free, potential corruption
kfree(fprog); // double free or corruption
Note: This was fixed in 3.17+ with commit 278571baca2a
("net: filter: simplify socket charging")
Found by AddressSanitizer
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: a3ea269b8bcdb ("net: filter: keep original BPF program around")
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/core/filter.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 1dbf6462f766..3139f966a178 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1318,6 +1318,7 @@ static int sk_store_orig_filter(struct sk_filter *fp, fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); if (!fkprog->filter) { kfree(fp->orig_prog); + fp->orig_prog = NULL; return -ENOMEM; } |