Lots of fixes in this release. On the security front, this kernel contains a fix for the most recent local root vulnerability made public today.

2.4.25 kernel (changelog)

Also, a number of UML-related bugs have been fixed. Full changelog here

• time_init calls timer to make sure that xtime is non-zero. This was the cause of /proc having a 1970 date.
• Changes HZ to 100, fixing some time problems, including ps start times drifting away from real time, and maybe some at brokenness.

How to Upgrade

See if you're already running 2.4.25-linode23-1um by viewing the output of "uname -a" inside your Linode. If not, follow this procedure:

Log into the Linode Platform Manager (LPM)
Configuration Profiles --> Click on your configuration profile
Make sure the Kernel drop-down has "Latest 2.4 Series" selected and Save
Reboot your Linode

Thanks and enjoy!

-Chris

CONFIG_ATALK=y
CONFIG_AUTOFS4_FS=y
CONFIG_AUTOFS_FS=y
CONFIG_BINFMT_AOUT=y
CONFIG_BINFMT_ELF=y
CONFIG_BINFMT_MISC=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_LVM=y
CONFIG_BLK_DEV_MD=y
CONFIG_BLK_DEV_RAM_SIZE=4096
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_UBD=y
CONFIG_BRIDGE=y
CONFIG_BSD_PROCESS_ACCT=y
CONFIG_CODA_FS=y
CONFIG_CON_CHAN="xterm"
CONFIG_CON_ZERO_CHAN="fd:0,fd:1"
CONFIG_COW_COMMON=y
CONFIG_COW=y
CONFIG_CRAMFS=y
CONFIG_CRC32=y
CONFIG_DEV_APPLETALK=y
CONFIG_DEVFS_FS=y
CONFIG_DEVFS_MOUNT=y
CONFIG_DEVPTS_FS=y
CONFIG_EXPERIMENTAL=y
CONFIG_EXT2_FS=y
CONFIG_EXT3_FS=y
CONFIG_FAT_FS=y
CONFIG_FD_CHAN=y
CONFIG_FILTER=y
CONFIG_HPFS_FS=y
CONFIG_INET=y
CONFIG_IP6_NF_FILTER=y
CONFIG_IP6_NF_IPTABLES=y
CONFIG_IP6_NF_MANGLE=y
CONFIG_IP6_NF_MATCH_LENGTH=y
CONFIG_IP6_NF_MATCH_LIMIT=y
CONFIG_IP6_NF_MATCH_MAC=y
CONFIG_IP6_NF_MATCH_MARK=y
CONFIG_IP6_NF_MATCH_MULTIPORT=y
CONFIG_IP6_NF_QUEUE=y
CONFIG_IP6_NF_TARGET_LOG=y
CONFIG_IP6_NF_TARGET_MARK=y
CONFIG_IP_ADVANCED_ROUTER=y
CONFIG_IPDDP_DECAP=y
CONFIG_IPDDP_ENCAP=y
CONFIG_IPDDP=y
CONFIG_IP_MROUTE=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_MULTIPLE_TABLES=y
CONFIG_IP_NF_ARPFILTER=y
CONFIG_IP_NF_ARPTABLES=y
CONFIG_IP_NF_CONNTRACK=y
CONFIG_IP_NF_FILTER=y
CONFIG_IP_NF_FTP=y
CONFIG_IP_NF_IPTABLES=y
CONFIG_IP_NF_IRC=y
CONFIG_IP_NF_MANGLE=y
CONFIG_IP_NF_MATCH_AH_ESP=y
CONFIG_IP_NF_MATCH_CONNTRACK=y
CONFIG_IP_NF_MATCH_DSCP=y
CONFIG_IP_NF_MATCH_ECN=y
CONFIG_IP_NF_MATCH_HELPER=y
CONFIG_IP_NF_MATCH_LENGTH=y
CONFIG_IP_NF_MATCH_LIMIT=y
CONFIG_IP_NF_MATCH_MAC=y
CONFIG_IP_NF_MATCH_MARK=y
CONFIG_IP_NF_MATCH_MULTIPORT=y
CONFIG_IP_NF_MATCH_OWNER=y
CONFIG_IP_NF_MATCH_PKTTYPE=y
CONFIG_IP_NF_MATCH_RECENT=y
CONFIG_IP_NF_MATCH_STATE=y
CONFIG_IP_NF_MATCH_TCPMSS=y
CONFIG_IP_NF_MATCH_TOS=y
CONFIG_IP_NF_MATCH_TTL=y
CONFIG_IP_NF_NAT_FTP=y
CONFIG_IP_NF_NAT_IRC=y
CONFIG_IP_NF_NAT_LOCAL=y
CONFIG_IP_NF_NAT_NEEDED=y
CONFIG_IP_NF_NAT=y
CONFIG_IP_NF_QUEUE=y
CONFIG_IP_NF_TARGET_DSCP=y
CONFIG_IP_NF_TARGET_ECN=y
CONFIG_IP_NF_TARGET_LOG=y
CONFIG_IP_NF_TARGET_MARK=y
CONFIG_IP_NF_TARGET_MASQUERADE=y
CONFIG_IP_NF_TARGET_REDIRECT=y
CONFIG_IP_NF_TARGET_REJECT=y
CONFIG_IP_NF_TARGET_TCPMSS=y
CONFIG_IP_NF_TARGET_TOS=y
CONFIG_IP_NF_TARGET_ULOG=y
CONFIG_IP_PIMSM_V1=y
CONFIG_IP_PIMSM_V2=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_RARP=y
CONFIG_IP_PNP=y
CONFIG_IP_ROUTE_FWMARK=y
CONFIG_IP_ROUTE_MULTIPATH=y
CONFIG_IP_ROUTE_NAT=y
CONFIG_IP_ROUTE_TOS=y
CONFIG_IP_ROUTE_VERBOSE=y
CONFIG_IPSEC_AH=y
CONFIG_IPSEC_AUTH_HMAC_MD5=y
CONFIG_IPSEC_AUTH_HMAC_SHA1=y
CONFIG_IPSEC_ENC_3DES=y
CONFIG_IPSEC_ESP=y
CONFIG_IPSEC_IPCOMP=y
CONFIG_IPSEC_IPIP=y
CONFIG_IPSEC=y
CONFIG_IPV6_SCTP__=y
CONFIG_IPV6=y
CONFIG_IPX_INTERN=y
CONFIG_IPX=y
CONFIG_ISO9660_FS=y
CONFIG_JBD=y
CONFIG_JFS_FS=y
CONFIG_JFS_STATISTICS=y
CONFIG_JOLIET=y
CONFIG_KERNEL_HALF_GIGS=1
CONFIG_KERNEL_STACK_ORDER=2
CONFIG_LOCKD_V4=y
CONFIG_LOCKD=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_MCONSOLE=y
CONFIG_MD_LINEAR=y
CONFIG_MD_MULTIPATH=y
CONFIG_MD_RAID0=y
CONFIG_MD_RAID1=y
CONFIG_MD_RAID5=y
CONFIG_MD=y
CONFIG_MINIX_FS=y
CONFIG_MODE_SKAS=y
CONFIG_MODE_TT=y
CONFIG_MSDOS_FS=y
CONFIG_MSDOS_PARTITION=y
CONFIG_NCPFS_EXTRAS=y
CONFIG_NCPFS_IOCTL_LOCKING=y
CONFIG_NCPFS_NFS_NS=y
CONFIG_NCPFS_NLS=y
CONFIG_NCPFS_OS2_NS=y
CONFIG_NCPFS_PACKET_SIGNING=y
CONFIG_NCPFS_STRONG=y
CONFIG_NCP_FS=y
CONFIG_NEST_LEVEL=0
CONFIG_NET_CLS_FW=y
CONFIG_NET_CLS_POLICE=y
CONFIG_NET_CLS_ROUTE4=y
CONFIG_NET_CLS_ROUTE=y
CONFIG_NET_CLS_RSVP6=y
CONFIG_NET_CLS_RSVP=y
CONFIG_NET_CLS_TCINDEX=y
CONFIG_NET_CLS_U32=y
CONFIG_NET_CLS=y
CONFIG_NETDEVICES=y
CONFIG_NET_ESTIMATOR=y
CONFIG_NETFILTER=y
CONFIG_NET_IPGRE_BROADCAST=y
CONFIG_NET_IPGRE=y
CONFIG_NET_IPIP=y
CONFIG_NET_QOS=y
CONFIG_NET_SCH_CBQ=y
CONFIG_NET_SCH_CSZ=y
CONFIG_NET_SCH_DSMARK=y
CONFIG_NET_SCHED=y
CONFIG_NET_SCH_GRED=y
CONFIG_NET_SCH_HTB=y
CONFIG_NET_SCH_INGRESS=y
CONFIG_NET_SCH_PRIO=y
CONFIG_NET_SCH_RED=y
CONFIG_NET_SCH_SFQ=y
CONFIG_NET_SCH_TBF=y
CONFIG_NET_SCH_TEQL=y
CONFIG_NET=y
CONFIG_NFS_DIRECTIO=y
CONFIG_NFSD_V3=y
CONFIG_NFSD=y
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_NLS_CODEPAGE_437=y
CONFIG_NLS_CODEPAGE_850=y
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_KOI8_R=y
CONFIG_NLS=y
CONFIG_NULL_CHAN=y
CONFIG_PACKET_MMAP=y
CONFIG_PACKET=y
CONFIG_PORT_CHAN=y
CONFIG_PPP_ASYNC=y
CONFIG_PPP_BSDCOMP=y
CONFIG_PPP_DEFLATE=y
CONFIG_PPP_FILTER=y
CONFIG_PPP_SYNC_TTY=y
CONFIG_PPP=y
CONFIG_PROC_FS=y
CONFIG_PROC_MM=y
CONFIG_PTY_CHAN=y
CONFIG_QFMT_V2=y
CONFIG_QUOTA=y
CONFIG_RAMFS=y
CONFIG_REISERFS_FS=y
CONFIG_REISERFS_PROC_INFO=y
CONFIG_ROMFS_FS=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_SLIP_COMPRESSED=y
CONFIG_SLIP=y
CONFIG_SMB_FS=y
CONFIG_SMB_NLS_DEFAULT=y
CONFIG_SMB_NLS_REMOTE="cp437"
CONFIG_SMB_NLS=y
CONFIG_SSL_CHAN="pty"
CONFIG_SSL=y
CONFIG_STDIO_CONSOLE=y
CONFIG_SUNRPC=y
CONFIG_SYN_COOKIES=y
CONFIG_SYSCTL=y
CONFIG_SYSVIPC=y
CONFIG_TMPFS=y
CONFIG_TTY_CHAN=y
CONFIG_TUN=y
CONFIG_UID16=y
CONFIG_UML_NET_TUNTAP=y
CONFIG_UML_NET=y
CONFIG_UML_REAL_TIME_CLOCK=y
CONFIG_UMSDOS_FS=y
CONFIG_UNIX98_PTY_COUNT=64
CONFIG_UNIX98_PTYS=y
CONFIG_UNIX=y
CONFIG_USERMODE=y
CONFIG_VFAT_FS=y
CONFIG_VLAN_8021Q=y
CONFIG_VXFS_FS=y
CONFIG_XTERM_CHAN=y
CONFIG_ZISOFS_FS=y
CONFIG_ZISOFS=y
CONFIG_ZLIB_DEFLATE=y
CONFIG_ZLIB_INFLATE=y

Thank you!
- kenny

The other day I went and read the dmesg log, and the first line mentioned /dev/anon. Being curious, I searched for info on this and it turns out it had to do with ubd=mmap memory management.

Then I noticed that for ubd=mmap to work the UML filesystem's block size has to be 4Kb (size of one page). I don't know about other fellow users but the blocksize for my ext2 image is 1K. Could this be one possible cause for the failure?

Nope -- the devanon patch has only been applied to a few of the later hosts' kernels. Once ubd=mmap is working properly (doesn't eat filesystems) and the devanon patch is available for 2.6 (which Linode is sponsoring the development of) and 2.6 is stable and tested, all of the hosts will be rebooted into 2.6 with devanon.

The devanon patch by itself doesn't provide much without udb=mmap.

You are correct that ubd=mmap requires 4k block sizes. The blocksize must equal the page size, which it will for all swap filesystems, which is where I'm looking to get the most benefit from ubd=mmap, anyway

Right now, only the debian template filesystem is using 1k block sizes, but I'll switch that over to 4k when all of this is ready...

-Chris

Once you switch the templates, will you describe how to fix it for those of us with running systems?

I use reiserfs, over LVM. Does the devanon stuff only matter at the LVM level (and do the LVM cluster sizes thus have to be made smaller.... 4k seems very small for LVM purposes though), or does it only matter at the VFS layer (ie, where reisferfs is now)?

Anywhere I can read up more on this stuff?

Jeff hasn't made this announcement yet, but chatting with him in #uml last week, he's determined that devanon and ubd-mmap won't work. Something about UML and the host sharing page cache, the data gets written in the correct order, but then the pages get moved around and that's what causes the corruption. And, there's no mechanism in Linux for positioning data in the page cache. So, devanon and ubd-mmap aren't going to work

He is working on mmap-hostfs, which I can tell you I'll never do -- since it requires your files existing on the host filesystem, and then passing that directory into UML. It also requires a file ownership mapping layer .. ugh.. No more block devices, no more LVM, etc.

More on this later...

-Chris