lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 1 Feb 2021 11:43:34 -0600
From:   "Gustavo A. R. Silva" <>
To:     "K. Y. Srinivasan" <>,
        Haiyang Zhang <>,
        Stephen Hemminger <>,
        Wei Liu <>
        "Gustavo A. R. Silva" <>,
Subject: [PATCH][next] hv: hyperv.h: Replace one-element array with
 flexible-array in struct icmsg_negotiate

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Refactor the code according to the use of a flexible-array member in
struct icmsg_negotiate, instead of a one-element array.

Also, this helps the ongoing efforts to enable -Warray-bounds and fix the
following warnings:

drivers/hv/channel_mgmt.c:315:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds]
drivers/hv/channel_mgmt.c:316:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds]


Signed-off-by: Gustavo A. R. Silva <>
 include/linux/hyperv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index f0d48a368f13..7877746f1077 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1528,14 +1528,14 @@ struct icmsg_hdr {
 #define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr))
 #define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \
-	(ICMSG_HDR + offsetof(struct icmsg_negotiate, icversion_data) + \
+	(ICMSG_HDR + sizeof(struct icmsg_negotiate) + \
 	 (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version)))
 struct icmsg_negotiate {
 	u16 icframe_vercnt;
 	u16 icmsg_vercnt;
 	u32 reserved;
-	struct ic_version icversion_data[1]; /* any size array */
+	struct ic_version icversion_data[]; /* any size array */
 } __packed;
 struct shutdown_msg_data {

Powered by blists - more mailing lists