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2021-07-23ima: Return int in the functions to measure a bufferRoberto Sassu2-22/+28
ima_measure_critical_data() and process_buffer_measurement() currently don't return a result as, unlike appraisal-related functions, the result is not used by callers to deny an operation. Measurement-related functions instead rely on the audit subsystem to notify the system administrator when an error occurs. However, ima_measure_critical_data() and process_buffer_measurement() are a special case, as these are the only functions that can return a buffer measurement (for files, there is ima_file_hash()). In a subsequent patch, they will be modified to return the calculated digest. In preparation to return the result of the digest calculation, this patch modifies the return type from void to int, and returns 0 if the buffer has been successfully measured, a negative value otherwise. Given that the result of the measurement is still not necessary, this patch does not modify the behavior of existing callers by processing the returned value. For those, the return value is ignored. Signed-off-by: Roberto Sassu <[email protected]> Reviewed-by: Lakshmi Ramasubramanian <[email protected]> Acked-by: Paul Moore <[email protected]> (for the SELinux bits) Signed-off-by: Mimi Zohar <[email protected]>
2021-07-23ima: Introduce ima_get_current_hash_algo()Roberto Sassu1-1/+6
Buffer measurements, unlike file measurements, are not accessible after the measurement is done, as buffers are not suitable for use with the integrity_iint_cache structure (there is no index, for files it is the inode number). In the subsequent patches, the measurement (digest) will be returned directly by the functions that perform the buffer measurement, ima_measure_critical_data() and process_buffer_measurement(). A caller of those functions also needs to know the algorithm used to calculate the digest. Instead of adding the algorithm as a new parameter to the functions, this patch provides it separately with the new function ima_get_current_hash_algo(). Since the hash algorithm does not change after the IMA setup phase, there is no risk of races (obtaining a digest calculated with a different algorithm than the one returned). Signed-off-by: Roberto Sassu <[email protected]> Reviewed-by: Lakshmi Ramasubramanian <[email protected]> [[email protected]: annotate ima_hash_algo as __ro_after_init] Signed-off-by: Mimi Zohar <[email protected]>
2021-07-23IMA: remove -Wmissing-prototypes warningAustin Kim1-1/+1
With W=1 build, the compiler throws warning message as below: security/integrity/ima/ima_mok.c:24:12: warning: no previous prototype for ‘ima_mok_init’ [-Wmissing-prototypes] __init int ima_mok_init(void) Silence the warning by adding static keyword to ima_mok_init(). Signed-off-by: Austin Kim <[email protected]> Fixes: 41c89b64d718 ("IMA: create machine owner and blacklist keyrings") Cc: [email protected] Signed-off-by: Mimi Zohar <[email protected]>
2021-07-20hardening: Clarify Kconfig text for auto-var-initKees Cook1-20/+32
Clarify the details around the automatic variable initialization modes available. Specifically this details the values used for pattern init and expands on the rationale for zero init safety. Additionally makes zero init the default when available. Cc: [email protected] Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Kees Cook <[email protected]> Acked-by: Gustavo A. R. Silva <[email protected]>
2021-07-20hardening: Introduce CONFIG_ZERO_CALL_USED_REGSKees Cook1-0/+19
When CONFIG_ZERO_CALL_USED_REGS is enabled, build the kernel with "-fzero-call-used-regs=used-gpr" (in GCC 11). This option will zero any caller-used register contents just before returning from a function, ensuring that temporary values are not leaked beyond the function boundary. This means that register contents are less likely to be available for side channel attacks and information exposures. Additionally this helps reduce the number of useful ROP gadgets in the kernel image by about 20%: $ ROPgadget.py --nosys --nojop --binary vmlinux.stock | tail -n1 Unique gadgets found: 337245 $ ROPgadget.py --nosys --nojop --binary vmlinux.zero-call-regs | tail -n1 Unique gadgets found: 267175 and more notably removes simple "write-what-where" gadgets: $ ROPgadget.py --ropchain --binary vmlinux.stock | sed -n '/Step 1/,/Step 2/p' - Step 1 -- Write-what-where gadgets [+] Gadget found: 0xffffffff8102d76c mov qword ptr [rsi], rdx ; ret [+] Gadget found: 0xffffffff81000cf5 pop rsi ; ret [+] Gadget found: 0xffffffff8104d7c8 pop rdx ; ret [-] Can't find the 'xor rdx, rdx' gadget. Try with another 'mov [reg], reg' [+] Gadget found: 0xffffffff814c2b4c mov qword ptr [rsi], rdi ; ret [+] Gadget found: 0xffffffff81000cf5 pop rsi ; ret [+] Gadget found: 0xffffffff81001e51 pop rdi ; ret [-] Can't find the 'xor rdi, rdi' gadget. Try with another 'mov [reg], reg' [+] Gadget found: 0xffffffff81540d61 mov qword ptr [rsi], rdi ; pop rbx ; pop rbp ; ret [+] Gadget found: 0xffffffff81000cf5 pop rsi ; ret [+] Gadget found: 0xffffffff81001e51 pop rdi ; ret [-] Can't find the 'xor rdi, rdi' gadget. Try with another 'mov [reg], reg' [+] Gadget found: 0xffffffff8105341e mov qword ptr [rsi], rax ; ret [+] Gadget found: 0xffffffff81000cf5 pop rsi ; ret [+] Gadget found: 0xffffffff81029a11 pop rax ; ret [+] Gadget found: 0xffffffff811f1c3b xor rax, rax ; ret - Step 2 -- Init syscall number gadgets $ ROPgadget.py --ropchain --binary vmlinux.zero* | sed -n '/Step 1/,/Step 2/p' - Step 1 -- Write-what-where gadgets [-] Can't find the 'mov qword ptr [r64], r64' gadget For an x86_64 parallel build tests, this has a less than 1% performance impact, and grows the image size less than 1%: $ size vmlinux.stock vmlinux.zero-call-regs text data bss dec hex filename 22437676 8559152 14127340 45124168 2b08a48 vmlinux.stock 22453184 8563248 14110956 45127388 2b096dc vmlinux.zero-call-regs Impact for other architectures may vary. For example, arm64 sees a 5.5% image size growth, mainly due to needing to always clear x16 and x17: https://lore.kernel.org/lkml/[email protected]/ Signed-off-by: Kees Cook <[email protected]>
2021-07-20smack: mark 'smack_enabled' global variable as __initdataAustin Kim2-2/+2
Mark 'smack_enabled' as __initdata since it is only used during initialization code. Signed-off-by: Austin Kim <[email protected]> Signed-off-by: Casey Schaufler <[email protected]>
2021-07-20Smack: Fix wrong semantics in smk_access_entry()Tianjia Zhang1-9/+8
In the smk_access_entry() function, if no matching rule is found in the rust_list, a negative error code will be used to perform bit operations with the MAY_ enumeration value. This is semantically wrong. This patch fixes this issue. Signed-off-by: Tianjia Zhang <[email protected]> Signed-off-by: Casey Schaufler <[email protected]>
2021-07-14selinux: return early for possible NULL audit buffersAustin Kim2-0/+6
audit_log_start() may return NULL in below cases: - when audit is not initialized. - when audit backlog limit exceeds. After the call to audit_log_start() is made and then possible NULL audit buffer argument is passed to audit_log_*() functions, audit_log_*() functions return immediately in case of a NULL audit buffer argument. But it is optimal to return early when audit_log_start() returns NULL, because it is not necessary for audit_log_*() functions to be called with NULL audit buffer argument. So add exception handling for possible NULL audit buffers where return value can be handled from callers. Signed-off-by: Austin Kim <[email protected]> [PM: tweak subject line] Signed-off-by: Paul Moore <[email protected]>
2021-07-02Merge tag 'asm-generic-unaligned-5.14' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 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/[email protected]/ Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363 Link: https://lore.kernel.org/lkml/[email protected]/ 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
2021-06-30Merge tag 'safesetid-5.14' of git://github.com/micah-morton/linuxLinus Torvalds2-2/+2
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
2021-06-30Merge tag 'Smack-for-5.14' of git://github.com/cschaufler/smack-nextLinus Torvalds2-5/+9
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
2021-06-30Merge tag 'audit-pr-20210629' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit 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
2021-06-30Merge tag 'selinux-pr-20210629' of ↵Linus Torvalds11-109/+81
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux 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()
2021-06-28Merge tag 'integrity-v5.14' of ↵Linus Torvalds18-75/+730
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 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 ...
2021-06-21evm: Check xattr size discrepancy between kernel and userRoberto Sassu1-1/+7
The kernel and the user obtain an xattr value in two different ways: kernel (EVM): uses vfs_getxattr_alloc() which obtains the xattr value from the filesystem handler (raw value); user (ima-evm-utils): uses vfs_getxattr() which obtains the xattr value from the LSMs (normalized value). Normally, this does not have an impact unless security.selinux is set with setfattr, with a value not terminated by '\0' (this is not the recommended way, security.selinux should be set with the appropriate tools such as chcon and restorecon). In this case, the kernel and the user see two different xattr values: the former sees the xattr value without '\0' (raw value), the latter sees the value with '\0' (value normalized by SELinux). This could result in two different verification outcomes from EVM and ima-evm-utils, if a signature was calculated with a security.selinux value terminated by '\0' and the value set in the filesystem is not terminated by '\0'. The former would report verification failure due to the missing '\0', while the latter would report verification success (because it gets the normalized value with '\0'). This patch mitigates this issue by comparing in evm_calc_hmac_or_hash() the size of the xattr returned by the two xattr functions and by warning the user if there is a discrepancy. Signed-off-by: Roberto Sassu <[email protected]> Suggested-by: Mimi Zohar <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-20evm: output EVM digest calculation infoMimi Zohar2-0/+47
Output the data used in calculating the EVM digest and the resulting digest as ascii hexadecimal strings. Suggested-by: Lakshmi Ramasubramanian <[email protected]> (CONFIG_DYNAMIC_DEBUG) Reviewed-by: Lakshmi Ramasubramanian <[email protected]> Reported-by: kernel test robot <[email protected]> (Use %zu for size_t) Signed-off-by: Mimi Zohar <[email protected]>
2021-06-16tomoyo: fix doc warningsChenXiaoSong4-9/+9
Fix gcc W=1 warnings: security/tomoyo/audit.c:331: warning: Function parameter or member 'matched_acl' not described in 'tomoyo_get_audit' security/tomoyo/securityfs_if.c:146: warning: Function parameter or member 'inode' not described in 'tomoyo_release' security/tomoyo/tomoyo.c:122: warning: Function parameter or member 'path' not described in 'tomoyo_inode_getattr' security/tomoyo/tomoyo.c:497: warning: Function parameter or member 'clone_flags' not described in 'tomoyo_task_alloc' security/tomoyo/util.c:92: warning: Function parameter or member 'time64' not described in 'tomoyo_convert_time' Signed-off-by: ChenXiaoSong <[email protected]> [ penguin-kernel: Also adjust spaces and similar warnings ] Signed-off-by: Tetsuo Handa <[email protected]>
2021-06-11audit: remove unnecessary 'ret' initializationAustin Kim1-1/+0
The variable 'ret' is set to 0 when declared. The 'ret' is unused until it is set to 0 again. So it had better remove unnecessary initialization. Signed-off-by: Austin Kim <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2021-06-11selinux: kill 'flags' argument in avc_has_perm_flags() and avc_audit()Al Viro3-31/+5
... along with avc_has_perm_flags() itself, since now it's identical to avc_has_perm() (as pointed out by Paul Moore) Signed-off-by: Al Viro <[email protected]> [PM: add "selinux:" prefix to subj and tweak for length] Signed-off-by: Paul Moore <[email protected]>
2021-06-11selinux: slow_avc_audit has become non-blockingAl Viro3-35/+10
dump_common_audit_data() is safe to use under rcu_read_lock() now; no need for AVC_NONBLOCKING and games around it Signed-off-by: Al Viro <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2021-06-11selinux: Fix kernel-docYang Li1-1/+22
Fix function name and add comment for parameter state in ss/services.c kernel-doc to remove some warnings found by running make W=1 LLVM=1. Reported-by: Abaci Robot <[email protected]> Signed-off-by: Yang Li <[email protected]> Signed-off-by: Paul Moore <[email protected]>
2021-06-11IMA: support for duplicate measurement recordsTushar Sugandhi2-2/+10
IMA measures contents of a given file/buffer/critical-data record, and properly re-measures it on change. However, IMA does not measure the duplicate value for a given record, since TPM extend is a very expensive operation. For example, if the record changes from value 'v#1' to 'v#2', and then back to 'v#1', IMA will not measure and log the last change to 'v#1', since the hash of 'v#1' for that record is already present in the IMA htable. This limits the ability of an external attestation service to accurately determine the current state of the system. The service would incorrectly conclude that the latest value of the given record on the system is 'v#2', and act accordingly. Define and use a new Kconfig option IMA_DISABLE_HTABLE to permit duplicate records in the IMA measurement list. In addition to the duplicate measurement records described above, other duplicate file measurement records may be included in the log, when CONFIG_IMA_DISABLE_HTABLE is enabled. For example, - i_version is not enabled, - i_generation changed, - same file present on different filesystems, - an inode is evicted from dcache Signed-off-by: Tushar Sugandhi <[email protected]> Reviewed-by: Petr Vorel <[email protected]> [[email protected]: updated list of duplicate measurement records] Signed-off-by: Mimi Zohar <[email protected]>
2021-06-11ima: Fix warning: no previous prototype for function 'ima_add_kexec_buffer'Lakshmi Ramasubramanian1-0/+1
The function prototype for ima_add_kexec_buffer() is present in 'linux/ima.h'. But this header file is not included in ima_kexec.c where the function is implemented. This results in the following compiler warning when "-Wmissing-prototypes" flag is turned on: security/integrity/ima/ima_kexec.c:81:6: warning: no previous prototype for function 'ima_add_kexec_buffer' [-Wmissing-prototypes] Include the header file 'linux/ima.h' in ima_kexec.c to fix the compiler warning. Fixes: dce92f6b11c3 (arm64: Enable passing IMA log to next kernel on kexec) Reported-by: kernel test robot <[email protected]> Signed-off-by: Lakshmi Ramasubramanian <[email protected]> Acked-by: Rob Herring <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-10selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVCMinchan Kim1-6/+7
In the field, we have seen lots of allocation failure from the call path below. 06-03 13:29:12.999 1010315 31557 31557 W Binder : 31542_2: page allocation failure: order:0, mode:0x800(GFP_NOWAIT), nodemask=(null),cpuset=background,mems_allowed=0 ... ... 06-03 13:29:12.999 1010315 31557 31557 W Call trace: 06-03 13:29:12.999 1010315 31557 31557 W : dump_backtrace.cfi_jt+0x0/0x8 06-03 13:29:12.999 1010315 31557 31557 W : dump_stack+0xc8/0x14c 06-03 13:29:12.999 1010315 31557 31557 W : warn_alloc+0x158/0x1c8 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_slowpath+0x9d8/0xb80 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_nodemask+0x1c4/0x430 06-03 13:29:12.999 1010315 31557 31557 W : allocate_slab+0xb4/0x390 06-03 13:29:12.999 1010315 31557 31557 W : ___slab_alloc+0x12c/0x3a4 06-03 13:29:12.999 1010315 31557 31557 W : kmem_cache_alloc+0x358/0x5e4 06-03 13:29:12.999 1010315 31557 31557 W : avc_alloc_node+0x30/0x184 06-03 13:29:12.999 1010315 31557 31557 W : avc_update_node+0x54/0x4f0 06-03 13:29:12.999 1010315 31557 31557 W : avc_has_extended_perms+0x1a4/0x460 06-03 13:29:12.999 1010315 31557 31557 W : selinux_file_ioctl+0x320/0x3d0 06-03 13:29:12.999 1010315 31557 31557 W : __arm64_sys_ioctl+0xec/0x1fc 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc_common+0xc0/0x24c 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc+0x28/0x88 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync_handler+0x8c/0xf0 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync+0x1a4/0x1c0 .. .. 06-03 13:29:12.999 1010315 31557 31557 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010315 31557 31557 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010315 31557 31557 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 10230 30892 30892 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 Based on [1], selinux is tolerate for failure of memory allocation. Then, use __GFP_NOWARN together. [1] 476accbe2f6e ("selinux: use GFP_NOWAIT in the AVC kmem_caches") Signed-off-by: Minchan Kim <[email protected]> [PM: subj fix, line wraps, normalized commit refs] Signed-off-by: Paul Moore <[email protected]>
2021-06-10ima: differentiate between EVM failures in the audit logMimi Zohar1-1/+2
Differentiate between an invalid EVM portable signature failure from other EVM HMAC/signature failures. Reviewed-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-10LSM: SafeSetID: Mark safesetid_initialized as __initdataAustin Kim2-2/+2
Mark safesetid_initialized as __initdata since it is only used in initialization routine. Signed-off-by: Austin Kim <[email protected]> Signed-off-by: Micah Morton <[email protected]>
2021-06-08ima: Fix fall-through warning for ClangGustavo A. R. Silva1-0/+1
In preparation to enable -Wimplicit-fallthrough for Clang, fix a fall-through warning by explicitly adding a break statement instead of just letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <[email protected]> Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-08ima: Pass NULL instead of 0 to ima_get_action() in ima_file_mprotect()Roberto Sassu1-1/+1
This patch fixes the sparse warning: sparse: warning: Using plain integer as NULL pointer Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-08ima: Include header defining ima_post_key_create_or_update()Roberto Sassu1-0/+1
This patch fixes the sparse warning for ima_post_key_create_or_update() by adding the header file that defines the prototype (linux/ima.h). Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-08ima/evm: Fix type mismatchRoberto Sassu4-11/+12
The endianness of a variable written to the measurement list cannot be determined at compile time, as it depends on the value of the ima_canonical_fmt global variable (set through a kernel option with the same name if the machine is big endian). If ima_canonical_fmt is false, the endianness of a variable is the same as the machine; if ima_canonical_fmt is true, the endianness is little endian. The warning arises due to this type of instruction: var = cpu_to_leXX(var) which tries to assign a value in little endian to a variable with native endianness (little or big endian). Given that the variables set with this instruction are not used in any operation but just written to a buffer, it is safe to force the type of the value being set to be the same of the type of the variable with: var = (__force <var type>)cpu_to_leXX(var) Reported-by: kernel test robot <[email protected]> Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-08ima: Set correct casting typesRoberto Sassu2-9/+10
The code expects that the values being parsed from a buffer when the ima_canonical_fmt global variable is true are in little endian. Thus, this patch sets the casting types accordingly. Reported-by: kernel test robot <[email protected]> Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-08Smack: fix doc warningChenXiaoSong1-1/+4
Fix gcc W=1 warning: security/smack/smack_access.c:342: warning: Function parameter or member 'ad' not described in 'smack_log' security/smack/smack_access.c:403: warning: Function parameter or member 'skp' not described in 'smk_insert_entry' security/smack/smack_access.c:487: warning: Function parameter or member 'level' not described in 'smk_netlbl_mls' security/smack/smack_access.c:487: warning: Function parameter or member 'len' not described in 'smk_netlbl_mls' Signed-off-by: ChenXiaoSong <[email protected]> Signed-off-by: Casey Schaufler <[email protected]>
2021-06-03evm: Don't return an error in evm_write_xattrs() if audit is not enabledRoberto Sassu1-1/+1
This patch avoids that evm_write_xattrs() returns an error when audit is not enabled. The ab variable can be NULL and still be passed to the other audit_log_() functions, as those functions do not include any instruction. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-03ima: Define new template evm-sigRoberto Sassu1-1/+4
With the recent introduction of the evmsig template field, remote verifiers can obtain the EVM portable signature instead of the IMA signature, to verify file metadata. After introducing the new fields to include file metadata in the measurement list, this patch finally defines the evm-sig template, whose format is: d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode xattrnames, xattrlengths and xattrvalues are populated only from defined EVM protected xattrs, i.e. the ones that EVM considers to verify the portable signature. xattrnames and xattrlengths are populated only if the xattr is present. xattrnames and xattrlengths are not necessary for verifying the EVM portable signature, but they are included for completeness of information, if a remote verifier wants to infer more from file metadata. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-02ima: Define new template fields xattrnames, xattrlengths and xattrvaluesRoberto Sassu4-0/+148
This patch defines the new template fields xattrnames, xattrlengths and xattrvalues, which contain respectively a list of xattr names (strings, separated by |), lengths (u32, hex) and values (hex). If an xattr is not present, the name and length are not displayed in the measurement list. Reported-by: kernel test robot <[email protected]> (Missing prototype def) Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01evm: Verify portable signatures against all protected xattrsRoberto Sassu4-12/+68
Currently, the evm_config_default_xattrnames array contains xattr names only related to LSMs which are enabled in the kernel configuration. However, EVM portable signatures do not depend on local information and a vendor might include in the signature calculation xattrs that are not enabled in the target platform. Just including all xattrs names in evm_config_default_xattrnames is not a safe approach, because a target system might have already calculated signatures or HMACs based only on the enabled xattrs. After applying this patch, EVM would verify those signatures and HMACs with all xattrs instead. The non-enabled ones, which could possibly exist, would cause a verification error. Thus, this patch adds a new field named enabled to the xattr_list structure, which is set to true if the LSM associated to a given xattr name is enabled in the kernel configuration. The non-enabled xattrs are taken into account only in evm_calc_hmac_or_hash(), if the passed security.evm type is EVM_XATTR_PORTABLE_DIGSIG. The new function evm_protected_xattr_if_enabled() has been defined so that IMA can include all protected xattrs and not only the enabled ones in the measurement list, if the new template fields xattrnames, xattrlengths or xattrvalues have been included in the template format. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Define new template field imodeRoberto Sassu3-0/+26
This patch defines the new template field imode, which includes the inode mode. It can be used by a remote verifier to verify the EVM portable signature, if it was included with the template fields sig or evmsig. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Define new template fields iuid and igidRoberto Sassu3-0/+53
This patch defines the new template fields iuid and igid, which include respectively the inode UID and GID. For idmapped mounts, still the original UID and GID are provided. These fields can be used to verify the EVM portable signature, if it was included with the template fields sig or evmsig. Signed-off-by: Roberto Sassu <[email protected]> Acked-by: Christian Brauner <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Add ima_show_template_uint() template library functionRoberto Sassu2-1/+39
This patch introduces the new function ima_show_template_uint(). This can be used for showing integers of different sizes in ASCII format. The function ima_show_template_data_ascii() automatically determines how to print a stored integer by checking the integer size. If integers have been written in canonical format, ima_show_template_data_ascii() calls the appropriate leXX_to_cpu() function to correctly display the value. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Don't remove security.ima if file must not be appraisedRoberto Sassu1-2/+0
Files might come from a remote source and might have xattrs, including security.ima. It should not be IMA task to decide whether security.ima should be kept or not. This patch removes the removexattr() system call in ima_inode_post_setattr(). Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Introduce template field evmsig and write to field sig as fallbackRoberto Sassu3-1/+36
With the patch to accept EVM portable signatures when the appraise_type=imasig requirement is specified in the policy, appraisal can be successfully done even if the file does not have an IMA signature. However, remote attestation would not see that a different signature type was used, as only IMA signatures can be included in the measurement list. This patch solves the issue by introducing the new template field 'evmsig' to show EVM portable signatures and by including its value in the existing field 'sig' if the IMA signature is not found. Suggested-by: Mimi Zohar <[email protected]> Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01ima: Allow imasig requirement to be satisfied by EVM portable signaturesRoberto Sassu1-7/+17
System administrators can require that all accessed files have a signature by specifying appraise_type=imasig in a policy rule. Currently, IMA signatures satisfy this requirement. Appended signatures may also satisfy this requirement, but are not applicable as IMA signatures. IMA/appended signatures ensure data source authentication for file content and prevent any change. EVM signatures instead ensure data source authentication for file metadata. Given that the digest or signature of the file content must be included in the metadata, EVM signatures provide the same file data guarantees of IMA signatures, as well as providing file metadata guarantees. This patch lets systems protected with EVM signatures pass appraisal verification if the appraise_type=imasig requirement is specified in the policy. This facilitates deployment in the scenarios where only EVM signatures are available. The patch makes the following changes: file xattr types: security.ima: IMA_XATTR_DIGEST/IMA_XATTR_DIGEST_NG security.evm: EVM_XATTR_PORTABLE_DIGSIG execve(), mmap(), open() behavior (with appraise_type=imasig): before: denied (file without IMA signature, imasig requirement not met) after: allowed (file with EVM portable signature, imasig requirement met) open(O_WRONLY) behavior (without appraise_type=imasig): before: allowed (file without IMA signature, not immutable) after: denied (file with EVM portable signature, immutable) In addition, similarly to IMA signatures, this patch temporarily allows new files without or with incomplete metadata to be opened so that content can be written. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-06-01evm: Allow setxattr() and setattr() for unmodified metadataRoberto Sassu1-1/+112
With the patch to allow xattr/attr operations if a portable signature verification fails, cp and tar can copy all xattrs/attrs so that at the end of the process verification succeeds. However, it might happen that the xattrs/attrs are already set to the correct value (taken at signing time) and signature verification succeeds before the copy has completed. For example, an archive might contains files owned by root and the archive is extracted by root. Then, since portable signatures are immutable, all subsequent operations fail (e.g. fchown()), even if the operation is legitimate (does not alter the current value). This patch avoids this problem by reporting successful operation to user space when that operation does not alter the current value of xattrs/attrs. With this patch, the one that introduces evm_hmac_disabled() and the one that allows a metadata operation on the INTEGRITY_FAIL_IMMUTABLE error, EVM portable signatures can be used without disabling metadata verification (by setting EVM_ALLOW_METADATA_WRITES). Due to keeping metadata verification enabled, altering immutable metadata protected with a portable signature that was successfully verified will be denied (existing behavior). Reported-by: kernel test robot <[email protected]> [implicit declaration of function] Signed-off-by: Roberto Sassu <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Cc: Andreas Gruenbacher <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Pass user namespace to set/remove xattr hooksRoberto Sassu2-8/+13
In preparation for 'evm: Allow setxattr() and setattr() for unmodified metadata', this patch passes mnt_userns to the inode set/remove xattr hooks so that the GID of the inode on an idmapped mount is correctly determined by posix_acl_update_mode(). Signed-off-by: Roberto Sassu <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Cc: Andreas Gruenbacher <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Allow xattr/attr operations for portable signaturesRoberto Sassu2-6/+29
If files with portable signatures are copied from one location to another or are extracted from an archive, verification can temporarily fail until all xattrs/attrs are set in the destination. Only portable signatures may be moved or copied from one file to another, as they don't depend on system-specific information such as the inode generation. Instead portable signatures must include security.ima. Unlike other security.evm types, EVM portable signatures are also immutable. Thus, it wouldn't be a problem to allow xattr/attr operations when verification fails, as portable signatures will never be replaced with the HMAC on possibly corrupted xattrs/attrs. This patch first introduces a new integrity status called INTEGRITY_FAIL_IMMUTABLE, that allows callers of evm_verify_current_integrity() to detect that a portable signature didn't pass verification and then adds an exception in evm_protect_xattr() and evm_inode_setattr() for this status and returns 0 instead of -EPERM. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Introduce evm_hmac_disabled() to safely ignore verification errorsRoberto Sassu1-1/+38
When a file is being created, LSMs can set the initial label with the inode_init_security hook. If no HMAC key is loaded, the new file will have LSM xattrs but not the HMAC. It is also possible that the file remains without protected xattrs after creation if no active LSM provided it, or because the filesystem does not support them. Unfortunately, EVM will deny any further metadata operation on new files, as evm_protect_xattr() will return the INTEGRITY_NOLABEL error if protected xattrs exist without security.evm, INTEGRITY_NOXATTRS if no protected xattrs exist or INTEGRITY_UNKNOWN if xattrs are not supported. This would limit the usability of EVM when only a public key is loaded, as commands such as cp or tar with the option to preserve xattrs won't work. This patch introduces the evm_hmac_disabled() function to determine whether or not it is safe to ignore verification errors, based on the ability of EVM to calculate HMACs. If the HMAC key is not loaded, and it cannot be loaded in the future due to the EVM_SETUP_COMPLETE initialization flag, allowing an operation despite the attrs/xattrs being found invalid will not make them valid. Since the post hooks can be executed even when the HMAC key is not loaded, this patch also ensures that the EVM_INIT_HMAC initialization flag is set before the post hooks call evm_update_evmxattr(). Signed-off-by: Roberto Sassu <[email protected]> Suggested-by: Mimi Zohar <[email protected]> (for ensuring EVM_INIT_HMAC is set) Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Introduce evm_revalidate_status()Roberto Sassu2-9/+46
When EVM_ALLOW_METADATA_WRITES is set, EVM allows any operation on metadata. Its main purpose is to allow users to freely set metadata when it is protected by a portable signature, until an HMAC key is loaded. However, callers of evm_verifyxattr() are not notified about metadata changes and continue to rely on the last status returned by the function. For example IMA, since it caches the appraisal result, will not call again evm_verifyxattr() until the appraisal flags are cleared, and will grant access to the file even if there was a metadata operation that made the portable signature invalid. This patch introduces evm_revalidate_status(), which callers of evm_verifyxattr() can use in their xattr hooks to determine whether re-validation is necessary and to do the proper actions. IMA calls it in its xattr hooks to reset the appraisal flags, so that the EVM status is re-evaluated after a metadata operation. Lastly, this patch also adds a call to evm_reset_status() in evm_inode_post_setattr() to invalidate the cached EVM status after a setattr operation. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loadedRoberto Sassu1-4/+4
EVM_ALLOW_METADATA_WRITES is an EVM initialization flag that can be set to temporarily disable metadata verification until all xattrs/attrs necessary to verify an EVM portable signature are copied to the file. This flag is cleared when EVM is initialized with an HMAC key, to avoid that the HMAC is calculated on unverified xattrs/attrs. Currently EVM unnecessarily denies setting this flag if EVM is initialized with a public key, which is not a concern as it cannot be used to trust xattrs/attrs updates. This patch removes this limitation. Fixes: ae1ba1676b88e ("EVM: Allow userland to permit modification of EVM-protected metadata") Signed-off-by: Roberto Sassu <[email protected]> Cc: [email protected] # 4.16.x Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Load EVM key in ima_load_x509() to avoid appraisalRoberto Sassu2-1/+7
The public builtin keys do not need to be appraised by IMA as the restriction on the IMA/EVM trusted keyrings ensures that a key can be loaded only if it is signed with a key on the builtin or secondary keyrings. However, when evm_load_x509() is called, appraisal is already enabled and a valid IMA signature must be added to the EVM key to pass verification. Since the restriction is applied on both IMA and EVM trusted keyrings, it is safe to disable appraisal also when the EVM key is loaded. This patch calls evm_load_x509() inside ima_load_x509() if CONFIG_IMA_LOAD_X509 is enabled, which crosses the normal IMA and EVM boundary. Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]>
2021-05-21evm: Execute evm_inode_init_security() only when an HMAC key is loadedRoberto Sassu1-2/+3
evm_inode_init_security() requires an HMAC key to calculate the HMAC on initial xattrs provided by LSMs. However, it checks generically whether a key has been loaded, including also public keys, which is not correct as public keys are not suitable to calculate the HMAC. Originally, support for signature verification was introduced to verify a possibly immutable initial ram disk, when no new files are created, and to switch to HMAC for the root filesystem. By that time, an HMAC key should have been loaded and usable to calculate HMACs for new files. More recently support for requiring an HMAC key was removed from the kernel, so that signature verification can be used alone. Since this is a legitimate use case, evm_inode_init_security() should not return an error when no HMAC key has been loaded. This patch fixes this problem by replacing the evm_key_loaded() check with a check of the EVM_INIT_HMAC flag in evm_initialized. Fixes: 26ddabfe96b ("evm: enable EVM when X509 certificate is loaded") Signed-off-by: Roberto Sassu <[email protected]> Cc: [email protected] # 4.5.x Signed-off-by: Mimi Zohar <[email protected]>
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