From: Trond Myklebust <trond.myklebust@hammerspace.com> stable inclusion from stable-v6.6.102 commit 12ad3def2e5e0b120e3d0cb6ce8b7b796819ad40 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/8984 CVE: CVE-2025-39730 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit ef93a685e01a281b5e2a25ce4e3428cf9371a205 ] The function needs to check the minimal filehandle length before it can access the embedded filehandle. Reported-by: zhangjian <zhangjian496@huawei.com> Fixes: 20fa19027286 ("nfs: add export operations") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com> --- fs/nfs/export.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/nfs/export.c b/fs/nfs/export.c index be686b8e0c54..aeb17adcb2b6 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -64,18 +64,25 @@ static struct dentry * nfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct nfs_fattr *fattr = NULL; struct nfs_fh *server_fh = nfs_exp_embedfh(fid->raw); - size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size; + size_t fh_size = offsetof(struct nfs_fh, data); const struct nfs_rpc_ops *rpc_ops; struct dentry *dentry; struct inode *inode; - int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size); + int len = EMBED_FH_OFF; u32 *p = fid->raw; int ret; + /* Initial check of bounds */ + if (fh_len < len + XDR_QUADLEN(fh_size) || + fh_len > XDR_QUADLEN(NFS_MAXFHSIZE)) + return NULL; + /* Calculate embedded filehandle size */ + fh_size += server_fh->size; + len += XDR_QUADLEN(fh_size); /* NULL translates to ESTALE */ if (fh_len < len || fh_type != len) return NULL; fattr = nfs_alloc_fattr_with_label(NFS_SB(sb)); -- 2.34.3