From cd409d0b83932f114e26b113910dc6a85030a30b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 19 Jun 2023 10:19:38 +0200 Subject: [PATCH] ksmbd: avoid field overflow warning [ Upstream commit 9cedc58bdbe9fff9aacd0ca19ee5777659f28fd7 ] clang warns about a possible field overflow in a memcpy: In file included from fs/smb/server/smb_common.c:7: include/linux/fortify-string.h:583:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] __write_overflow_field(p_size_field, size); It appears to interpret the "&out[baselen + 4]" as referring to a single byte of the character array, while the equivalen "out + baselen + 4" is seen as an offset into the array. I don't see that kind of warning elsewhere, so just go with the simple rework. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Signed-off-by: Arnd Bergmann Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/ksmbd/smb_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c index 569e5eecdf3d..3e391a7d5a3a 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -536,7 +536,7 @@ int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, out[baselen + 3] = PERIOD; if (dot_present) - memcpy(&out[baselen + 4], extension, 4); + memcpy(out + baselen + 4, extension, 4); else out[baselen + 4] = '\0'; smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,