Loading Documentation/ABI/testing/sysfs-block-rssd +0 −21 Original line number Diff line number Diff line What: /sys/block/rssd*/registers Date: March 2012 KernelVersion: 3.3 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Dumps below driver information and hardware registers. - S ACTive - Command Issue - Completed - PORT IRQ STAT - HOST IRQ STAT - Allocated - Commands in Q What: /sys/block/rssd*/status Date: April 2012 KernelVersion: 3.4 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Indicates the status of the device. What: /sys/block/rssd*/flags Date: May 2012 KernelVersion: 3.5 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Dumps the flags in port and driver data structure Documentation/device-mapper/verity.txt +46 −85 Original line number Diff line number Diff line Loading @@ -7,13 +7,13 @@ This target is read-only. Construction Parameters ======================= <version> <dev> <hash_dev> <hash_start> <version> <dev> <hash_dev> <data_block_size> <hash_block_size> <num_data_blocks> <hash_start_block> <algorithm> <digest> <salt> <version> This is the version number of the on-disk format. This is the type of the on-disk hash format. 0 is the original format used in the Chromium OS. The salt is appended when hashing, digests are stored continuously and Loading @@ -24,22 +24,22 @@ Construction Parameters padded with zeros to the power of two. <dev> This is the device containing the data the integrity of which needs to be This is the device containing data, the integrity of which needs to be checked. It may be specified as a path, like /dev/sdaX, or a device number, <major>:<minor>. <hash_dev> This is the device that that supplies the hash tree data. It may be This is the device that supplies the hash tree data. It may be specified similarly to the device path and may be the same device. If the same device is used, the hash_start should be outside of the dm-verity configured device size. same device is used, the hash_start should be outside the configured dm-verity device. <data_block_size> The block size on a data device. Each block corresponds to one digest on the hash device. The block size on a data device in bytes. Each block corresponds to one digest on the hash device. <hash_block_size> The size of a hash block. The size of a hash block in bytes. <num_data_blocks> The number of data blocks on the data device. Additional blocks are Loading Loading @@ -73,20 +73,20 @@ When a dm-verity device is configured, it is expected that the caller has been authenticated in some way (cryptographic signatures, etc). After instantiation, all hashes will be verified on-demand during disk access. If they cannot be verified up to the root node of the tree, the root hash, then the I/O will fail. This should identify tree, the root hash, then the I/O will fail. This should detect tampering with any data on the device and the hash data. Cryptographic hashes are used to assert the integrity of the device on a per-block basis. This allows for a lightweight hash computation on first read into the page cache. Block hashes are stored linearly-aligned to the nearest block the size of a page. into the page cache. Block hashes are stored linearly, aligned to the nearest block size. Hash Tree --------- Each node in the tree is a cryptographic hash. If it is a leaf node, the hash is of some block data on disk. If it is an intermediary node, then the hash is of a number of child nodes. of some data block on disk is calculated. If it is an intermediary node, the hash of a number of child nodes is calculated. Each entry in the tree is a collection of neighboring nodes that fit in one block. The number is determined based on block_size and the size of the Loading @@ -110,63 +110,23 @@ alg = sha256, num_blocks = 32768, block_size = 4096 On-disk format ============== Below is the recommended on-disk format. The verity kernel code does not read the on-disk header. It only reads the hash blocks which directly follow the header. It is expected that a user-space tool will verify the integrity of the verity_header and then call dmsetup with the correct parameters. Alternatively, the header can be omitted and the dmsetup parameters can be passed via the kernel command-line in a rooted chain of trust where the command-line is verified. The verity kernel code does not read the verity metadata on-disk header. It only reads the hash blocks which directly follow the header. It is expected that a user-space tool will verify the integrity of the verity header. The on-disk format is especially useful in cases where the hash blocks are on a separate partition. The magic number allows easy identification of the partition contents. Alternatively, the hash blocks can be stored in the same partition as the data to be verified. In such a configuration the filesystem on the partition would be sized a little smaller than the full-partition, leaving room for the hash blocks. struct superblock { uint8_t signature[8] "verity\0\0"; uint8_t version; 1 - current format uint8_t data_block_bits; log2(data block size) uint8_t hash_block_bits; log2(hash block size) uint8_t pad1[1]; zero padding uint16_t salt_size; big-endian salt size uint8_t pad2[2]; zero padding uint32_t data_blocks_hi; big-endian high 32 bits of the 64-bit number of data blocks uint32_t data_blocks_lo; big-endian low 32 bits of the 64-bit number of data blocks uint8_t algorithm[16]; cryptographic algorithm uint8_t salt[384]; salt (the salt size is specified above) uint8_t pad3[88]; zero padding to 512-byte boundary } Alternatively, the header can be omitted and the dmsetup parameters can be passed via the kernel command-line in a rooted chain of trust where the command-line is verified. Directly following the header (and with sector number padded to the next hash block boundary) are the hash blocks which are stored a depth at a time (starting from the root), sorted in order of increasing index. The full specification of kernel parameters and on-disk metadata format is available at the cryptsetup project's wiki page http://code.google.com/p/cryptsetup/wiki/DMVerity Status ====== V (for Valid) is returned if every check performed so far was valid. Loading @@ -174,21 +134,22 @@ If any check failed, C (for Corruption) is returned. Example ======= Set up a device: dmsetup create vroot --table \ "0 2097152 "\ "verity 1 /dev/sda1 /dev/sda2 4096 4096 2097152 1 "\ # dmsetup create vroot --readonly --table \ "0 2097152 verity 1 /dev/sda1 /dev/sda2 4096 4096 262144 1 sha256 "\ "4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 "\ "1234000000000000000000000000000000000000000000000000000000000000" A command line tool veritysetup is available to compute or verify the hash tree or activate the kernel driver. This is available from the LVM2 upstream repository and may be supplied as a package called device-mapper-verity-tools: git://sources.redhat.com/git/lvm2 http://sourceware.org/git/?p=lvm2.git http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/verity?cvsroot=lvm2 veritysetup -a vroot /dev/sda1 /dev/sda2 \ the hash tree or activate the kernel device. This is available from the cryptsetup upstream repository http://code.google.com/p/cryptsetup/ (as a libcryptsetup extension). Create hash on the device: # veritysetup format /dev/sda1 /dev/sda2 ... Root hash: 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 Activate the device: # veritysetup create vroot /dev/sda1 /dev/sda2 \ 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 Documentation/prctl/no_new_privs.txt 0 → 100644 +50 −0 Original line number Diff line number Diff line The execve system call can grant a newly-started program privileges that its parent did not have. The most obvious examples are setuid/setgid programs and file capabilities. To prevent the parent program from gaining these privileges as well, the kernel and user code must be careful to prevent the parent from doing anything that could subvert the child. For example: - The dynamic loader handles LD_* environment variables differently if a program is setuid. - chroot is disallowed to unprivileged processes, since it would allow /etc/passwd to be replaced from the point of view of a process that inherited chroot. - The exec code has special handling for ptrace. These are all ad-hoc fixes. The no_new_privs bit (since Linux 3.5) is a new, generic mechanism to make it safe for a process to modify its execution environment in a manner that persists across execve. Any task can set no_new_privs. Once the bit is set, it is inherited across fork, clone, and execve and cannot be unset. With no_new_privs set, execve promises not to grant the privilege to do anything that could not have been done without the execve call. For example, the setuid and setgid bits will no longer change the uid or gid; file capabilities will not add to the permitted set, and LSMs will not relax constraints after execve. Note that no_new_privs does not prevent privilege changes that do not involve execve. An appropriately privileged task can still call setuid(2) and receive SCM_RIGHTS datagrams. There are two main use cases for no_new_privs so far: - Filters installed for the seccomp mode 2 sandbox persist across execve and can change the behavior of newly-executed programs. Unprivileged users are therefore only allowed to install such filters if no_new_privs is set. - By itself, no_new_privs can be used to reduce the attack surface available to an unprivileged user. If everything running with a given uid has no_new_privs set, then that uid will be unable to escalate its privileges by directly attacking setuid, setgid, and fcap-using binaries; it will need to compromise something without the no_new_privs bit set first. In the future, other potentially dangerous kernel features could become available to unprivileged tasks if no_new_privs is set. In principle, several options to unshare(2) and clone(2) would be safe when no_new_privs is set, and no_new_privs + chroot is considerable less dangerous than chroot by itself. Documentation/stable_kernel_rules.txt +6 −0 Original line number Diff line number Diff line Loading @@ -12,6 +12,12 @@ Rules on what kind of patches are accepted, and which ones are not, into the marked CONFIG_BROKEN), an oops, a hang, data corruption, a real security issue, or some "oh, that's not good" issue. In short, something critical. - Serious issues as reported by a user of a distribution kernel may also be considered if they fix a notable performance or interactivity issue. As these fixes are not as obvious and have a higher risk of a subtle regression they should only be submitted by a distribution kernel maintainer and include an addendum linking to a bugzilla entry if it exists and additional information on the user-visible impact. - New device IDs and quirks are also accepted. - No "theoretical race condition" issues, unless an explanation of how the race can be exploited is also provided. Loading MAINTAINERS +2 −2 Original line number Diff line number Diff line Loading @@ -4655,8 +4655,8 @@ L: netfilter@vger.kernel.org L: coreteam@netfilter.org W: http://www.netfilter.org/ W: http://www.iptables.org/ T: git git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-2.6.git T: git git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next-2.6.git T: git git://1984.lsi.us.es/nf T: git git://1984.lsi.us.es/nf-next S: Supported F: include/linux/netfilter* F: include/linux/netfilter/ Loading Loading
Documentation/ABI/testing/sysfs-block-rssd +0 −21 Original line number Diff line number Diff line What: /sys/block/rssd*/registers Date: March 2012 KernelVersion: 3.3 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Dumps below driver information and hardware registers. - S ACTive - Command Issue - Completed - PORT IRQ STAT - HOST IRQ STAT - Allocated - Commands in Q What: /sys/block/rssd*/status Date: April 2012 KernelVersion: 3.4 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Indicates the status of the device. What: /sys/block/rssd*/flags Date: May 2012 KernelVersion: 3.5 Contact: Asai Thambi S P <asamymuthupa@micron.com> Description: This is a read-only file. Dumps the flags in port and driver data structure
Documentation/device-mapper/verity.txt +46 −85 Original line number Diff line number Diff line Loading @@ -7,13 +7,13 @@ This target is read-only. Construction Parameters ======================= <version> <dev> <hash_dev> <hash_start> <version> <dev> <hash_dev> <data_block_size> <hash_block_size> <num_data_blocks> <hash_start_block> <algorithm> <digest> <salt> <version> This is the version number of the on-disk format. This is the type of the on-disk hash format. 0 is the original format used in the Chromium OS. The salt is appended when hashing, digests are stored continuously and Loading @@ -24,22 +24,22 @@ Construction Parameters padded with zeros to the power of two. <dev> This is the device containing the data the integrity of which needs to be This is the device containing data, the integrity of which needs to be checked. It may be specified as a path, like /dev/sdaX, or a device number, <major>:<minor>. <hash_dev> This is the device that that supplies the hash tree data. It may be This is the device that supplies the hash tree data. It may be specified similarly to the device path and may be the same device. If the same device is used, the hash_start should be outside of the dm-verity configured device size. same device is used, the hash_start should be outside the configured dm-verity device. <data_block_size> The block size on a data device. Each block corresponds to one digest on the hash device. The block size on a data device in bytes. Each block corresponds to one digest on the hash device. <hash_block_size> The size of a hash block. The size of a hash block in bytes. <num_data_blocks> The number of data blocks on the data device. Additional blocks are Loading Loading @@ -73,20 +73,20 @@ When a dm-verity device is configured, it is expected that the caller has been authenticated in some way (cryptographic signatures, etc). After instantiation, all hashes will be verified on-demand during disk access. If they cannot be verified up to the root node of the tree, the root hash, then the I/O will fail. This should identify tree, the root hash, then the I/O will fail. This should detect tampering with any data on the device and the hash data. Cryptographic hashes are used to assert the integrity of the device on a per-block basis. This allows for a lightweight hash computation on first read into the page cache. Block hashes are stored linearly-aligned to the nearest block the size of a page. into the page cache. Block hashes are stored linearly, aligned to the nearest block size. Hash Tree --------- Each node in the tree is a cryptographic hash. If it is a leaf node, the hash is of some block data on disk. If it is an intermediary node, then the hash is of a number of child nodes. of some data block on disk is calculated. If it is an intermediary node, the hash of a number of child nodes is calculated. Each entry in the tree is a collection of neighboring nodes that fit in one block. The number is determined based on block_size and the size of the Loading @@ -110,63 +110,23 @@ alg = sha256, num_blocks = 32768, block_size = 4096 On-disk format ============== Below is the recommended on-disk format. The verity kernel code does not read the on-disk header. It only reads the hash blocks which directly follow the header. It is expected that a user-space tool will verify the integrity of the verity_header and then call dmsetup with the correct parameters. Alternatively, the header can be omitted and the dmsetup parameters can be passed via the kernel command-line in a rooted chain of trust where the command-line is verified. The verity kernel code does not read the verity metadata on-disk header. It only reads the hash blocks which directly follow the header. It is expected that a user-space tool will verify the integrity of the verity header. The on-disk format is especially useful in cases where the hash blocks are on a separate partition. The magic number allows easy identification of the partition contents. Alternatively, the hash blocks can be stored in the same partition as the data to be verified. In such a configuration the filesystem on the partition would be sized a little smaller than the full-partition, leaving room for the hash blocks. struct superblock { uint8_t signature[8] "verity\0\0"; uint8_t version; 1 - current format uint8_t data_block_bits; log2(data block size) uint8_t hash_block_bits; log2(hash block size) uint8_t pad1[1]; zero padding uint16_t salt_size; big-endian salt size uint8_t pad2[2]; zero padding uint32_t data_blocks_hi; big-endian high 32 bits of the 64-bit number of data blocks uint32_t data_blocks_lo; big-endian low 32 bits of the 64-bit number of data blocks uint8_t algorithm[16]; cryptographic algorithm uint8_t salt[384]; salt (the salt size is specified above) uint8_t pad3[88]; zero padding to 512-byte boundary } Alternatively, the header can be omitted and the dmsetup parameters can be passed via the kernel command-line in a rooted chain of trust where the command-line is verified. Directly following the header (and with sector number padded to the next hash block boundary) are the hash blocks which are stored a depth at a time (starting from the root), sorted in order of increasing index. The full specification of kernel parameters and on-disk metadata format is available at the cryptsetup project's wiki page http://code.google.com/p/cryptsetup/wiki/DMVerity Status ====== V (for Valid) is returned if every check performed so far was valid. Loading @@ -174,21 +134,22 @@ If any check failed, C (for Corruption) is returned. Example ======= Set up a device: dmsetup create vroot --table \ "0 2097152 "\ "verity 1 /dev/sda1 /dev/sda2 4096 4096 2097152 1 "\ # dmsetup create vroot --readonly --table \ "0 2097152 verity 1 /dev/sda1 /dev/sda2 4096 4096 262144 1 sha256 "\ "4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 "\ "1234000000000000000000000000000000000000000000000000000000000000" A command line tool veritysetup is available to compute or verify the hash tree or activate the kernel driver. This is available from the LVM2 upstream repository and may be supplied as a package called device-mapper-verity-tools: git://sources.redhat.com/git/lvm2 http://sourceware.org/git/?p=lvm2.git http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/verity?cvsroot=lvm2 veritysetup -a vroot /dev/sda1 /dev/sda2 \ the hash tree or activate the kernel device. This is available from the cryptsetup upstream repository http://code.google.com/p/cryptsetup/ (as a libcryptsetup extension). Create hash on the device: # veritysetup format /dev/sda1 /dev/sda2 ... Root hash: 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 Activate the device: # veritysetup create vroot /dev/sda1 /dev/sda2 \ 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076
Documentation/prctl/no_new_privs.txt 0 → 100644 +50 −0 Original line number Diff line number Diff line The execve system call can grant a newly-started program privileges that its parent did not have. The most obvious examples are setuid/setgid programs and file capabilities. To prevent the parent program from gaining these privileges as well, the kernel and user code must be careful to prevent the parent from doing anything that could subvert the child. For example: - The dynamic loader handles LD_* environment variables differently if a program is setuid. - chroot is disallowed to unprivileged processes, since it would allow /etc/passwd to be replaced from the point of view of a process that inherited chroot. - The exec code has special handling for ptrace. These are all ad-hoc fixes. The no_new_privs bit (since Linux 3.5) is a new, generic mechanism to make it safe for a process to modify its execution environment in a manner that persists across execve. Any task can set no_new_privs. Once the bit is set, it is inherited across fork, clone, and execve and cannot be unset. With no_new_privs set, execve promises not to grant the privilege to do anything that could not have been done without the execve call. For example, the setuid and setgid bits will no longer change the uid or gid; file capabilities will not add to the permitted set, and LSMs will not relax constraints after execve. Note that no_new_privs does not prevent privilege changes that do not involve execve. An appropriately privileged task can still call setuid(2) and receive SCM_RIGHTS datagrams. There are two main use cases for no_new_privs so far: - Filters installed for the seccomp mode 2 sandbox persist across execve and can change the behavior of newly-executed programs. Unprivileged users are therefore only allowed to install such filters if no_new_privs is set. - By itself, no_new_privs can be used to reduce the attack surface available to an unprivileged user. If everything running with a given uid has no_new_privs set, then that uid will be unable to escalate its privileges by directly attacking setuid, setgid, and fcap-using binaries; it will need to compromise something without the no_new_privs bit set first. In the future, other potentially dangerous kernel features could become available to unprivileged tasks if no_new_privs is set. In principle, several options to unshare(2) and clone(2) would be safe when no_new_privs is set, and no_new_privs + chroot is considerable less dangerous than chroot by itself.
Documentation/stable_kernel_rules.txt +6 −0 Original line number Diff line number Diff line Loading @@ -12,6 +12,12 @@ Rules on what kind of patches are accepted, and which ones are not, into the marked CONFIG_BROKEN), an oops, a hang, data corruption, a real security issue, or some "oh, that's not good" issue. In short, something critical. - Serious issues as reported by a user of a distribution kernel may also be considered if they fix a notable performance or interactivity issue. As these fixes are not as obvious and have a higher risk of a subtle regression they should only be submitted by a distribution kernel maintainer and include an addendum linking to a bugzilla entry if it exists and additional information on the user-visible impact. - New device IDs and quirks are also accepted. - No "theoretical race condition" issues, unless an explanation of how the race can be exploited is also provided. Loading
MAINTAINERS +2 −2 Original line number Diff line number Diff line Loading @@ -4655,8 +4655,8 @@ L: netfilter@vger.kernel.org L: coreteam@netfilter.org W: http://www.netfilter.org/ W: http://www.iptables.org/ T: git git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-2.6.git T: git git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next-2.6.git T: git git://1984.lsi.us.es/nf T: git git://1984.lsi.us.es/nf-next S: Supported F: include/linux/netfilter* F: include/linux/netfilter/ Loading
