This is a note to let you know that I've just added the patch titled
bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-add-length-check-for-sk_diag_bpf_storage_req_map.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c3d506eb1fa5785253d25ea582be0492ff74bf54
Author: Lin Ma <linma@xxxxxxxxxx>
Date: Tue Jul 25 10:33:30 2023 +0800
bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
[ Upstream commit bcc29b7f5af6797702c2306a7aacb831fc5ce9cb ]
The nla_for_each_nested parsing in function bpf_sk_storage_diag_alloc
does not check the length of the nested attribute. This can lead to an
out-of-attribute read and allow a malformed nlattr (e.g., length 0) to
be viewed as a 4 byte integer.
This patch adds an additional check when the nlattr is getting counted.
This makes sure the latter nla_get_u32 can access the attributes with
the correct length.
Fixes: 1ed4d92458a9 ("bpf: INET_DIAG support in bpf_sk_storage")
Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230725023330.422856-1-linma@xxxxxxxxxx
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index d67d06d6b817c..a811fe0f0f6fd 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -446,8 +446,11 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
return ERR_PTR(-EPERM);
nla_for_each_nested(nla, nla_stgs, rem) {
- if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
+ if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD) {
+ if (nla_len(nla) != sizeof(u32))
+ return ERR_PTR(-EINVAL);
nr_maps++;
+ }
}
diag = kzalloc(sizeof(*diag) + sizeof(diag->maps[0]) * nr_maps,
