linux/security, branch v5.14

bpf: Add lockdown check for probe_write_user helper

2021-08-10T08:10:10Z

Back then, commit 96ae52279594 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers") added the bpf_probe_write_user() helper in order to allow to override user space memory. Its original goal was to have a facility to "debug, divert, and manipulate execution of semi-cooperative processes" under CAP_SYS_ADMIN. Write to kernel was explicitly disallowed since it would otherwise tamper with its integrity. One use case was shown in cf9b1199de27 ("samples/bpf: Add test/example of using bpf_probe_write_user bpf helper") where the program DNATs traffic at the time of connect(2) syscall, meaning, it rewrites the arguments to a syscall while they're still in userspace, and before the syscall has a chance to copy the argument into kernel space. These days we have better mechanisms in BPF for achieving the same (e.g. for load-balancers), but without having to write to userspace memory. Of course the bpf_probe_write_user() helper can also be used to abuse many other things for both good or bad purpose. Outside of BPF, there is a similar mechanism for ptrace(2) such as PTRACE_PEEK{TEXT,DATA} and PTRACE_POKE{TEXT,DATA}, but would likely require some more effort. Commit 96ae52279594 explicitly dedicated the helper for experimentation purpose only. Thus, move the helper's availability behind a newly added LOCKDOWN_BPF_WRITE_USER lockdown knob so that the helper is disabled under the "integrity" mode. More fine-grained control can be implemented also from LSM side with this change. Fixes: 96ae52279594 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers") Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko

bpf: Add _kernel suffix to internal lockdown_bpf_read

2021-08-09T19:50:41Z

Rename LOCKDOWN_BPF_READ into LOCKDOWN_BPF_READ_KERNEL so we have naming more consistent with a LOCKDOWN_BPF_WRITE_USER option that we are adding. Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko

Merge tag 'selinux-pr-20210805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2021-08-05T19:06:31Z

Pull selinux fix from Paul Moore: "One small SELinux fix for a problem where an error code was not being propagated back up to userspace when a bogus SELinux policy is loaded into the kernel" * tag 'selinux-pr-20210805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: correct the return value when loads initial sids

selinux: correct the return value when loads initial sids

2021-08-02T13:59:50Z

It should not return 0 when SID 0 is assigned to isids. This patch fixes it. Cc: stable@vger.kernel.org Fixes: e3e0b582c321a ("selinux: remove unused initial SIDs and improve handling") Signed-off-by: Xiu Jianfeng [PM: remove changelog from description] Signed-off-by: Paul Moore

Merge tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2021-07-02T19:43:40Z

Pull asm/unaligned.h unification from Arnd Bergmann: "Unify asm/unaligned.h around struct helper The get_unaligned()/put_unaligned() helpers are traditionally architecture specific, with the two main variants being the "access-ok.h" version that assumes unaligned pointer accesses always work on a particular architecture, and the "le-struct.h" version that casts the data to a byte aligned type before dereferencing, for architectures that cannot always do unaligned accesses in hardware. Based on the discussion linked below, it appears that the access-ok version is not realiable on any architecture, but the struct version probably has no downsides. This series changes the code to use the same implementation on all architectures, addressing the few exceptions separately" Link: https://lore.kernel.org/lkml/75d07691-1e4f-741f-9852-38c0b4f520bc@synopsys.com/ Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363 Link: https://lore.kernel.org/lkml/20210507220813.365382-14-arnd@kernel.org/ Link: git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git unaligned-rework-v2 Link: https://lore.kernel.org/lkml/CAHk-=whGObOKruA_bU3aPGZfoDqZM1_9wBkwREp0H0FgR-90uQ@mail.gmail.com/ * tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic: simplify asm/unaligned.h asm-generic: uaccess: 1-byte access is always aligned netpoll: avoid put_unaligned() on single character mwifiex: re-fix for unaligned accesses apparmor: use get_unaligned() only for multi-byte words partitions: msdos: fix one-byte get_unaligned() asm-generic: unaligned always use struct helpers asm-generic: unaligned: remove byteshift helpers powerpc: use linux/unaligned/le_struct.h on LE power7 m68k: select CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS sh: remove unaligned access for sh4a openrisc: always use unaligned-struct header asm-generic: use asm-generic/unaligned.h for most architectures

Merge tag 'safesetid-5.14' of git://github.com/micah-morton/linux

2021-06-30T22:30:47Z

Pull SafeSetID update from Micah Morton: "One very minor code cleanup change that marks a variable as __initdata" * tag 'safesetid-5.14' of git://github.com/micah-morton/linux: LSM: SafeSetID: Mark safesetid_initialized as __initdata

Merge tag 'Smack-for-5.14' of git://github.com/cschaufler/smack-next

2021-06-30T22:28:43Z

Pull smack updates from Casey Schaufler: "There is nothing more significant than an improvement to a byte count check in smackfs. All changes have been in next for weeks" * tag 'Smack-for-5.14' of git://github.com/cschaufler/smack-next: Smack: fix doc warning Revert "Smack: Handle io_uring kernel thread privileges" smackfs: restrict bytes count in smk_set_cipso() security/smack/: fix misspellings using codespell tool

Merge tag 'audit-pr-20210629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

2021-06-30T22:22:05Z

Pull audit updates from Paul Moore: "Another merge window, another small audit pull request. Four patches in total: one is cosmetic, one removes an unnecessary initialization, one renames some enum values to prevent name collisions, and one converts list_del()/list_add() to list_move(). None of these are earth shattering and all pass the audit-testsuite tests while merging cleanly on top of your tree from earlier today" * tag 'audit-pr-20210629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: remove unnecessary 'ret' initialization audit: remove trailing spaces and tabs audit: Use list_move instead of list_del/list_add audit: Rename enum audit_state constants to avoid AUDIT_DISABLED redefinition audit: add blank line after variable declarations

Merge tag 'selinux-pr-20210629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2021-06-30T21:55:42Z

Pull SELinux updates from Paul Moore: - The slow_avc_audit() function is now non-blocking so we can remove the AVC_NONBLOCKING tricks; this also includes the 'flags' variant of avc_has_perm(). - Use kmemdup() instead of kcalloc()+copy when copying parts of the SELinux policydb. - The InfiniBand device name is now passed by reference when possible in the SELinux code, removing a strncpy(). - Minor cleanups including: constification of avtab function args, removal of useless LSM/XFRM function args, SELinux kdoc fixes, and removal of redundant assignments. * tag 'selinux-pr-20210629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: kill 'flags' argument in avc_has_perm_flags() and avc_audit() selinux: slow_avc_audit has become non-blocking selinux: Fix kernel-doc selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVC lsm_audit,selinux: pass IB device name by reference selinux: Remove redundant assignment to rc selinux: Corrected comment to match kernel-doc comment selinux: delete selinux_xfrm_policy_lookup() useless argument selinux: constify some avtab function arguments selinux: simplify duplicate_policydb_cond_list() by using kmemdup()

Merge tag 'integrity-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2021-06-28T23:15:50Z

Pull integrity subsystem updates from Mimi Zohar: "The large majority of the changes are EVM portable & immutable signature related: removing a dependency on loading an HMAC key, safely allowing file metadata included in the EVM portable & immutable signatures to be modified, allowing EVM signatures to fulfill IMA file signature policy requirements, including the EVM file metadata signature in lieu of an IMA file data signature in the measurement list, and adding dynamic debugging of EVM file metadata. In addition, in order to detect critical data or file change reversions, duplicate measurement records are permitted in the IMA measurement list. The remaining patches address compiler, sparse, and doc warnings" * tag 'integrity-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: (31 commits) evm: Check xattr size discrepancy between kernel and user evm: output EVM digest calculation info IMA: support for duplicate measurement records ima: Fix warning: no previous prototype for function 'ima_add_kexec_buffer' ima: differentiate between EVM failures in the audit log ima: Fix fall-through warning for Clang ima: Pass NULL instead of 0 to ima_get_action() in ima_file_mprotect() ima: Include header defining ima_post_key_create_or_update() ima/evm: Fix type mismatch ima: Set correct casting types doc: Fix warning in Documentation/security/IMA-templates.rst evm: Don't return an error in evm_write_xattrs() if audit is not enabled ima: Define new template evm-sig ima: Define new template fields xattrnames, xattrlengths and xattrvalues evm: Verify portable signatures against all protected xattrs ima: Define new template field imode ima: Define new template fields iuid and igid ima: Add ima_show_template_uint() template library function ima: Don't remove security.ima if file must not be appraised ima: Introduce template field evmsig and write to field sig as fallback ...