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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 29 Jan 2010 23:09:37 +0100
From:	Felix Fietkau <>
CC:	Lennert Buytenhek <>
Subject: [PATCH] skbuff: align sk_buff::cb to 64 bit

The alignment requirement for 64-bit load/store instructions on ARM is
implementation defined. Some CPUs (such as Marvell Feroceon) do not
generate an exception, if such an instruction is executed with an
address that is not 64 bit aligned. 
In such a case, the Feroceon corrupts adjacent memory, which showed up
in my tests as a crash in the rx path of ath9k that only occured with
CONFIG_XFRM set. This crash happened, because the first field of the
mac80211 rx status info in the cb is an u64, and changing it corrupted
the skb->sp field.

Signed-off-by: Felix Fietkau <>
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -329,7 +329,7 @@ struct sk_buff {
 	 * want to keep them across layers you have to do a skb_clone()
 	 * first. This is owned by whoever has the skb queued ATM.
-	char			cb[48];
+	char			cb[48] __attribute__((aligned(8)));
 	unsigned int		len,

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists