From 72c14aed6838b5d90b4dd926b6a339b34bb02e08 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 10 Jun 2025 16:55:04 -0700 Subject: [PATCH] NFSD: Fix NFSv3 SETATTR/CREATE's handling of large file sizes [ Upstream commit a648fdeb7c0e17177a2280344d015dba3fbe3314 ] iattr::ia_size is a loff_t, so these NFSv3 procedures must be careful to deal with incoming client size values that are larger than s64_max without corrupting the value. Silently capping the value results in storing a different value than the client passed in which is unexpected behavior, so remove the min_t() check in decode_sattr3(). Note that RFC 1813 permits only the WRITE procedure to return NFS3ERR_FBIG. We believe that NFSv3 reference implementations also return NFS3ERR_FBIG when ia_size is too large. Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever (cherry picked from commit a648fdeb7c0e17177a2280344d015dba3fbe3314) [Larry: backport to 5.4.y. Minor conflict resolved due to missing commit 9cde9360d18d NFSD: Update the SETATTR3args decoder to use struct xdr_stream] Signed-off-by: Larry Bassel Signed-off-by: Sasha Levin --- fs/nfsd/nfs3xdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 03e8c45a52f3..25b6b4db0af2 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -122,7 +122,7 @@ decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns) iap->ia_valid |= ATTR_SIZE; p = xdr_decode_hyper(p, &newsize); - iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX); + iap->ia_size = newsize; } if ((tmp = ntohl(*p++)) == 1) { /* set to server time */ iap->ia_valid |= ATTR_ATIME;