| Message ID | 20230607123612.2791303-1-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Smack transmute fixes | expand |
On 6/7/2023 5:36 AM, Roberto Sassu wrote: > From: Roberto Sassu <roberto.sassu@huawei.com> > > The first two patches are obvious fixes, the first restricts setting the > SMACK64TRANSMUTE xattr only for directories, and the second makes it > possible to set SMACK64TRANSMUTE if the filesystem does not support xattrs > (e.g. ramfs). > > The remaining fixes are optional, and only required if we want filesystems > without xattr support behave like those with xattr support. Since we have > the inode_setsecurity and inode_getsecurity hooks to make the first group > work, it seems useful to fix inode creation too (SELinux should be fine). > > The third patch is merely a code move out of the 'if (xattr)' condition. > The fourth updates the security field of the in-memory inode directly in > smack_inode_init_security() and marks the inode as instantiated, and the > fifth adds a security_inode_init_security() call in ramfs to initialize the > security field of the in-memory inodes (needed to test transmuting > directories). > > Both the Smack (on xfs) and IMA test suite succeed with all patches > applied. > > By setting the ROOT variable to a ramfs mountpoint, the results are: > > Without the patches: > 86 Passed, 9 Failed, 90% Success rate > > With the patches: > 93 Passed, 2 Failed, 97% Success rate > > The remaining two failures are: > 2151 ioctl(4, BTRFS_IOC_CLONE or FICLONE, 3) = -1 EOPNOTSUPP (Operation not supported) > 2152 lsetxattr("./targets/proc-attr-Snap", "security.SMACK64EXEC", "Pop", 3, 0) = -1 EOPNOTSUPP (Operation not supported) > > The first one is likely due ramfs lack of support for ioctl() while the > second could be fixed by handling SMACK64EXEC in smack_inode_setsecurity(). > > The patch set applies on top of: > > https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git/log/?h=next > > plus: > > https://github.com/cschaufler/smack-next/commits/next > > plus: > > https://lore.kernel.org/linux-integrity/20230603191518.1397490-1-roberto.sassu@huaweicloud.com/ > > The ramfs patch potentially could be useful to correctly initialize the > label of new inodes in the initramfs, assuming that it will be fully > labeled with support for xattrs in the cpio image: > > https://lore.kernel.org/linux-integrity/20190523121803.21638-1-roberto.sassu@huawei.com/ > > Ramfs inode labels will be set from xattrs with the inode_setsecurity hook. > > Roberto Sassu (5): > smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr() > smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() > smack: Always determine inode labels in smack_inode_init_security() > smack: Initialize the in-memory inode in smack_inode_init_security() > ramfs: Initialize security of in-memory inodes > > fs/ramfs/inode.c | 27 +++++++++++ > security/smack/smack_lsm.c | 93 ++++++++++++++++++++++---------------- > 2 files changed, 82 insertions(+), 38 deletions(-) I will run these through my test cycle, but they look good at first glance. Thank you.
From: Roberto Sassu <roberto.sassu@huawei.com> The first two patches are obvious fixes, the first restricts setting the SMACK64TRANSMUTE xattr only for directories, and the second makes it possible to set SMACK64TRANSMUTE if the filesystem does not support xattrs (e.g. ramfs). The remaining fixes are optional, and only required if we want filesystems without xattr support behave like those with xattr support. Since we have the inode_setsecurity and inode_getsecurity hooks to make the first group work, it seems useful to fix inode creation too (SELinux should be fine). The third patch is merely a code move out of the 'if (xattr)' condition. The fourth updates the security field of the in-memory inode directly in smack_inode_init_security() and marks the inode as instantiated, and the fifth adds a security_inode_init_security() call in ramfs to initialize the security field of the in-memory inodes (needed to test transmuting directories). Both the Smack (on xfs) and IMA test suite succeed with all patches applied. By setting the ROOT variable to a ramfs mountpoint, the results are: Without the patches: 86 Passed, 9 Failed, 90% Success rate With the patches: 93 Passed, 2 Failed, 97% Success rate The remaining two failures are: 2151 ioctl(4, BTRFS_IOC_CLONE or FICLONE, 3) = -1 EOPNOTSUPP (Operation not supported) 2152 lsetxattr("./targets/proc-attr-Snap", "security.SMACK64EXEC", "Pop", 3, 0) = -1 EOPNOTSUPP (Operation not supported) The first one is likely due ramfs lack of support for ioctl() while the second could be fixed by handling SMACK64EXEC in smack_inode_setsecurity(). The patch set applies on top of: https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git/log/?h=next plus: https://github.com/cschaufler/smack-next/commits/next plus: https://lore.kernel.org/linux-integrity/20230603191518.1397490-1-roberto.sassu@huaweicloud.com/ The ramfs patch potentially could be useful to correctly initialize the label of new inodes in the initramfs, assuming that it will be fully labeled with support for xattrs in the cpio image: https://lore.kernel.org/linux-integrity/20190523121803.21638-1-roberto.sassu@huawei.com/ Ramfs inode labels will be set from xattrs with the inode_setsecurity hook. Roberto Sassu (5): smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr() smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() smack: Always determine inode labels in smack_inode_init_security() smack: Initialize the in-memory inode in smack_inode_init_security() ramfs: Initialize security of in-memory inodes fs/ramfs/inode.c | 27 +++++++++++ security/smack/smack_lsm.c | 93 ++++++++++++++++++++++---------------- 2 files changed, 82 insertions(+), 38 deletions(-)