Commit 5304877936c0 ("NFSD: Fix strncpy() fortify warning") replaced
strncpy(,, sizeof(..)) with strlcpy(,, sizeof(..) - 1), but strlcpy()
already guaranteed NUL-termination of the destination buffer and
subtracting one byte potentially truncated the source string.
The incorrect size was then carried over in commit 72f78ae00a8e ("NFSD:
move from strlcpy with unused retval to strscpy") when switching from
strlcpy() to strscpy().
Fix this off-by-one error by using the full size of the destination
buffer again.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5304877936c0 ("NFSD: Fix strncpy() fortify warning")
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
---
Changes in v2:
- Use three parameter variant of strscpy() for easier backporting
- Link to v1: https://lore.kernel.org/lkml/20250805175302.29386-2-thorsten.blum@xxxxxxxxx/
---
fs/nfsd/nfs4proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 71b428efcbb5..954543e92988 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1469,7 +1469,7 @@ static __be32 nfsd4_ssc_setup_dul(struct nfsd_net *nn, char *ipaddr,
return 0;
}
if (work) {
- strscpy(work->nsui_ipaddr, ipaddr, sizeof(work->nsui_ipaddr) - 1);
+ strscpy(work->nsui_ipaddr, ipaddr, sizeof(work->nsui_ipaddr));
refcount_set(&work->nsui_refcnt, 2);
work->nsui_busy = true;
list_add_tail(&work->nsui_list, &nn->nfsd_ssc_mount_list);
--
2.50.1
