[PATCH bpf-next v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.

[PATCH bpf-next v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.

[Tal Lossos]

bpf_fd_inode_storage_lookup_elem returned NULL when getting a bad FD,
which caused -ENOENT in bpf_map_copy_value.
EBADF is better than ENOENT for a bad FD behaviour.

The patch was partially contributed by CyberArk Software, Inc.

Signed-off-by: Tal Lossos <tallossos@gmail.com>
---
 kernel/bpf/bpf_inode_storage.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index da753721457c..2921ca39a93e 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -109,7 +109,7 @@ static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
 	fd = *(int *)key;
 	f = fget_raw(fd);
 	if (!f)
-		return NULL;
+		return ERR_PTR(-EBADF);
 
 	sdata = inode_storage_lookup(f->f_inode, map, true);
 	fput(f);
-- 
2.27.0

Re: [PATCH bpf-next v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.

[Yonghong Song]

On 3/7/21 4:09 AM, Tal Lossos wrote:
> bpf_fd_inode_storage_lookup_elem returned NULL when getting a bad FD,
> which caused -ENOENT in bpf_map_copy_value.
> EBADF is better than ENOENT for a bad FD behaviour.
> 
> The patch was partially contributed by CyberArk Software, Inc.
> 
> Signed-off-by: Tal Lossos <tallossos@gmail.com>

Acked-by: Yonghong Song <yhs@fb.com>

Re: [PATCH bpf-next v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.

[KP Singh]

On Sun, Mar 7, 2021 at 7:18 PM Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 3/7/21 4:09 AM, Tal Lossos wrote:
> > bpf_fd_inode_storage_lookup_elem returned NULL when getting a bad FD,
> > which caused -ENOENT in bpf_map_copy_value.
> > EBADF is better than ENOENT for a bad FD behaviour.
> >
> > The patch was partially contributed by CyberArk Software, Inc.
> >
> > Signed-off-by: Tal Lossos <tallossos@gmail.com>
>
> Acked-by: Yonghong Song <yhs@fb.com>

Thanks this makes sense and is consistent with sk_storage (which
uses sockfd_lookup) and task_storage (which uses pidfd_get_pid)
which return an -EBADF as well.

Acked-by: KP Singh <kpsingh@kernel.org>

Re: [PATCH bpf-next v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf.git (refs/heads/master):

On Sun,  7 Mar 2021 14:09:48 +0200 you wrote:
> bpf_fd_inode_storage_lookup_elem returned NULL when getting a bad FD,
> which caused -ENOENT in bpf_map_copy_value.
> EBADF is better than ENOENT for a bad FD behaviour.
> 
> The patch was partially contributed by CyberArk Software, Inc.
> 
> Signed-off-by: Tal Lossos <tallossos@gmail.com>
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2] bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF.
    https://git.kernel.org/bpf/bpf/c/769c18b254ca

You are awesome, thank you!
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