From: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> stable inclusion from stable-v5.10.112 commit 4e166a41180be2f1e66bbb6d46448e80a9a5ec05 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5HL0X Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 64c4a37ac04eeb43c42d272f6e6c8c12bfcf4304 ] Smatch printed a warning: arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error: __memcpy() 'dctx->buf' too small (16 vs u32max) It's caused because Smatch marks 'link_len' as untrusted since it comes from sscanf(). Add a check to ensure that 'link_len' is not larger than the size of the 'link_str' buffer. Fixes: c69c1b6eaea1 ("cifs: implement CIFSParseMFSymlink()") Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- fs/cifs/link.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 94dab4309fbb..85d30fef98a2 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -97,6 +97,9 @@ parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len, if (rc != 1) return -EINVAL; + if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN) + return -EINVAL; + rc = symlink_hash(link_len, link_str, md5_hash); if (rc) { cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc); -- 2.20.1