[PATCH v2 2/2] sunrpc: honor the netlink unix_gid NEGATIVE flag
Ameer Hamza <[email protected]>
| Newsgroups | gmane.linux.nfs,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
The unix_gid netlink upcall protocol has an explicit
SUNRPC_A_UNIX_GID_NEGATIVE attribute for failed group lookups, and
mountd sends it, but sunrpc_nl_parse_one_unix_gid() only allocates
an empty group list for a flagged reply without propagating the
flag into the entry, so it installs a valid positive entry with
zero groups. Such an entry strips the uid of all supplementary
groups until it is refreshed or expires: the same defect the
previous patch fixes on the classic channel, on a transport that
can say "lookup failed" explicitly.
Set CACHE_NEGATIVE for flagged replies, as the netlink ip_map
path already does for its negative flag. An empty GIDS list
without the flag remains a positive entry.
Fixes: 0850e8603cd7 ("sunrpc: add netlink upcall for the auth.unix.gid cache")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Ameer Hamza <[email protected]>
---
net/sunrpc/svcauth_unix.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 2f592ba54a366..4dd28749bd5de 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -737,6 +737,8 @@ static int sunrpc_nl_parse_one_unix_gid(struct cache_detail *cd,
boot.tv_sec;
if (tb[SUNRPC_A_UNIX_GID_NEGATIVE]) {
+ /* failed lookup: keep the credential's own groups */
+ set_bit(CACHE_NEGATIVE, &ug.h.flags);
ug.gi = groups_alloc(0);
if (!ug.gi)
return -ENOMEM;
--
2.53.0