From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- fs/smb/client/unc.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 fs/smb/client/unc.c (limited to 'fs/smb/client/unc.c') diff --git a/fs/smb/client/unc.c b/fs/smb/client/unc.c new file mode 100644 index 000000000..f6fc5e343 --- /dev/null +++ b/fs/smb/client/unc.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2020, Microsoft Corporation. + * + * Author(s): Steve French + * Suresh Jayaraman + * Jeff Layton + */ + +#include +#include +#include +#include +#include "cifsglob.h" +#include "cifsproto.h" + +/* extract the host portion of the UNC string */ +char *extract_hostname(const char *unc) +{ + const char *src; + char *dst, *delim; + unsigned int len; + + /* skip double chars at beginning of string */ + /* BB: check validity of these bytes? */ + if (strlen(unc) < 3) + return ERR_PTR(-EINVAL); + for (src = unc; *src && *src == '\\'; src++) + ; + if (!*src) + return ERR_PTR(-EINVAL); + + /* delimiter between hostname and sharename is always '\\' now */ + delim = strchr(src, '\\'); + if (!delim) + return ERR_PTR(-EINVAL); + + len = delim - src; + dst = kmalloc((len + 1), GFP_KERNEL); + if (dst == NULL) + return ERR_PTR(-ENOMEM); + + memcpy(dst, src, len); + dst[len] = '\0'; + + return dst; +} + +char *extract_sharename(const char *unc) +{ + const char *src; + char *delim, *dst; + + /* skip double chars at the beginning */ + src = unc + 2; + + /* share name is always preceded by '\\' now */ + delim = strchr(src, '\\'); + if (!delim) + return ERR_PTR(-EINVAL); + delim++; + + /* caller has to free the memory */ + dst = kstrdup(delim, GFP_KERNEL); + if (!dst) + return ERR_PTR(-ENOMEM); + + return dst; +} -- cgit v1.3.1