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| author | Andrii Nakryiko <andriin@fb.com> | 2020-04-23 22:20:44 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-04-24 17:27:02 -0700 |
| commit | 4adb7a4a151c65ac7e9c3a1aa462c84190d48385 (patch) | |
| tree | 776699a09bc08d7e2c68d409e67616827ad3a399 | |
| parent | 5ca1ca01fae1e90f8d010eb1d83374f28dc11ee6 (diff) | |
| download | linux-4adb7a4a151c65ac7e9c3a1aa462c84190d48385.tar.gz linux-4adb7a4a151c65ac7e9c3a1aa462c84190d48385.tar.bz2 linux-4adb7a4a151c65ac7e9c3a1aa462c84190d48385.zip | |
bpf: Fix leak in LINK_UPDATE and enforce empty old_prog_fd
Fix bug of not putting bpf_link in LINK_UPDATE command.
Also enforce zeroed old_prog_fd if no BPF_F_REPLACE flag is specified.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200424052045.4002963-1-andriin@fb.com
| -rw-r--r-- | kernel/bpf/syscall.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d85f37239540..bca58c235ac0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3628,8 +3628,10 @@ static int link_update(union bpf_attr *attr) return PTR_ERR(link); new_prog = bpf_prog_get(attr->link_update.new_prog_fd); - if (IS_ERR(new_prog)) - return PTR_ERR(new_prog); + if (IS_ERR(new_prog)) { + ret = PTR_ERR(new_prog); + goto out_put_link; + } if (flags & BPF_F_REPLACE) { old_prog = bpf_prog_get(attr->link_update.old_prog_fd); @@ -3638,6 +3640,9 @@ static int link_update(union bpf_attr *attr) old_prog = NULL; goto out_put_progs; } + } else if (attr->link_update.old_prog_fd) { + ret = -EINVAL; + goto out_put_progs; } #ifdef CONFIG_CGROUP_BPF @@ -3653,6 +3658,8 @@ out_put_progs: bpf_prog_put(old_prog); if (ret) bpf_prog_put(new_prog); +out_put_link: + bpf_link_put(link); return ret; } |