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6 daysima: Handle error code returned by ima_filter_rule_match()Zhao Yipeng1-1/+1
[ Upstream commit 738c9738e690f5cea24a3ad6fd2d9a323cf614f6 ] In ima_match_rules(), if ima_filter_rule_match() returns -ENOENT due to the rule being NULL, the function incorrectly skips the 'if (!rc)' check and sets 'result = true'. The LSM rule is considered a match, causing extra files to be measured by IMA. This issue can be reproduced in the following scenario: After unloading the SELinux policy module via 'semodule -d', if an IMA measurement is triggered before ima_lsm_rules is updated, in ima_match_rules(), the first call to ima_filter_rule_match() returns -ESTALE. This causes the code to enter the 'if (rc == -ESTALE && !rule_reinitialized)' block, perform ima_lsm_copy_rule() and retry. In ima_lsm_copy_rule(), since the SELinux module has been removed, the rule becomes NULL, and the second call to ima_filter_rule_match() returns -ENOENT. This bypasses the 'if (!rc)' check and results in a false match. Call trace: selinux_audit_rule_match+0x310/0x3b8 security_audit_rule_match+0x60/0xa0 ima_match_rules+0x2e4/0x4a0 ima_match_policy+0x9c/0x1e8 ima_get_action+0x48/0x60 process_measurement+0xf8/0xa98 ima_bprm_check+0x98/0xd8 security_bprm_check+0x5c/0x78 search_binary_handler+0x6c/0x318 exec_binprm+0x58/0x1b8 bprm_execve+0xb8/0x130 do_execveat_common.isra.0+0x1a8/0x258 __arm64_sys_execve+0x48/0x68 invoke_syscall+0x50/0x128 el0_svc_common.constprop.0+0xc8/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x44/0x200 el0t_64_sync_handler+0x100/0x130 el0t_64_sync+0x3c8/0x3d0 Fix this by changing 'if (!rc)' to 'if (rc <= 0)' to ensure that error codes like -ENOENT do not bypass the check and accidentally result in a successful match. Fixes: 4af4662fa4a9d ("integrity: IMA policy") Signed-off-by: Zhao Yipeng <zhaoyipeng5@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14ima: Fix use-after-free on a dentry's dname.nameStefan Berger2-7/+26
commit be84f32bb2c981ca670922e047cdde1488b233de upstream. ->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name instead. Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Libo Chen <libo.chen.cn@windriver.com>
2024-07-18ima: Avoid blocking in RCU read-side critical sectionGUO Zihua2-7/+10
commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua <guozihua@huawei.com> Acked-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28ima: detect changes to the backing overlay fileMimi Zohar3-1/+22
commit b836c4d29f2744200b2af41e14bf50758dddc818 upstream. Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for IMA") forced signature re-evaulation on every file access. Instead of always re-evaluating the file's integrity, detect a change to the backing file, by comparing the cached file metadata with the backing file's metadata. Verifying just the i_version has not changed is insufficient. In addition save and compare the i_ino and s_dev as well. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Eric Snowberg <eric.snowberg@oracle.com> Tested-by: Raul E Rangel <rrangel@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28ima: annotate iint mutex to avoid lockdep false positive warningsAmir Goldstein1-11/+37
commit e044374a8a0a99e46f4e6d6751d3042b6d9cc12e upstream. It is not clear that IMA should be nested at all, but as long is it measures files both on overlayfs and on underlying fs, we need to annotate the iint mutex to avoid lockdep false positives related to IMA + overlayfs, same as overlayfs annotates the inode mutex. Reported-and-tested-by: syzbot+b42fe626038981fb7bfa@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-10ima: rework CONFIG_IMA dependency blockArnd Bergmann1-12/+6
[ Upstream commit 91e326563ee34509c35267808a4b1b3ea3db62a8 ] Changing the direct dependencies of IMA_BLACKLIST_KEYRING and IMA_LOAD_X509 caused them to no longer depend on IMA, but a a configuration without IMA results in link failures: arm-linux-gnueabi-ld: security/integrity/iint.o: in function `integrity_load_keys': iint.c:(.init.text+0xd8): undefined reference to `ima_load_x509' aarch64-linux-ld: security/integrity/digsig_asymmetric.o: in function `asymmetric_verify': digsig_asymmetric.c:(.text+0x104): undefined reference to `ima_blacklist_keyring' Adding explicit dependencies on IMA would fix this, but a more reliable way to do this is to enclose the entire Kconfig file in an 'if IMA' block. This also allows removing the existing direct dependencies. Fixes: be210c6d3597f ("ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10ima: Finish deprecation of IMA_TRUSTED_KEYRING KconfigOleksandr Tymoshenko1-2/+2
[ Upstream commit be210c6d3597faf330cb9af33b9f1591d7b2a983 ] The removal of IMA_TRUSTED_KEYRING made IMA_LOAD_X509 and IMA_BLACKLIST_KEYRING unavailable because the latter two depend on the former. Since IMA_TRUSTED_KEYRING was deprecated in favor of INTEGRITY_TRUSTED_KEYRING use it as a dependency for the two Kconfigs affected by the deprecation. Fixes: 5087fd9e80e5 ("ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig") Signed-off-by: Oleksandr Tymoshenko <ovt@google.com> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19ima: Remove deprecated IMA_TRUSTED_KEYRING KconfigNayna Jain1-12/+0
[ Upstream commit 5087fd9e80e539d2163accd045b73da64de7de95 ] Time to remove "IMA_TRUSTED_KEYRING". Fixes: f4dc37785e9b ("integrity: define '.evm' as a builtin 'trusted' keyring") # v4.5+ Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19of: kexec: Mark ima_{free,stable}_kexec_buffer() as __initNathan Chancellor2-2/+2
This commit has no direct upstream equivalent. After commit d48016d74836 ("mm,ima,kexec,of: use memblock_free_late from ima_free_kexec_buffer") in 5.15, there is a modpost warning for certain configurations: WARNING: modpost: vmlinux.o(.text+0xb14064): Section mismatch in reference from the function ima_free_kexec_buffer() to the function .init.text:__memblock_free_late() The function ima_free_kexec_buffer() references the function __init __memblock_free_late(). This is often because ima_free_kexec_buffer lacks a __init annotation or the annotation of __memblock_free_late is wrong. In mainline, there is no issue because ima_free_kexec_buffer() is marked as __init, which was done as part of commit b69a2afd5afc ("x86/kexec: Carry forward IMA measurement log on kexec") in 6.0, which is not suitable for stable. Mark ima_free_kexec_buffer() and its single caller ima_load_kexec_buffer() as __init in 5.15, as ima_load_kexec_buffer() is only called from ima_init(), which is __init, clearing up the warning. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-23integrity: Fix possible multiple allocation in integrity_inode_get()Tianjia Zhang1-6/+9
commit 9df6a4870dc371136e90330cfbbc51464ee66993 upstream. When integrity_inode_get() is querying and inserting the cache, there is a conditional race in the concurrent environment. The race condition is the result of not properly implementing "double-checked locking". In this case, it first checks to see if the iint cache record exists before taking the lock, but doesn't check again after taking the integrity_iint_lock. Fixes: bf2276d10ce5 ("ima: allocating iint improvements") Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-23ima: Fix build warningsRoberto Sassu2-1/+5
[ Upstream commit 95526d13038c2bbddd567a4d8e39fac42484e182 ] Fix build warnings (function parameters description) for ima_collect_modsig(), ima_match_policy() and ima_parse_add_rule(). Fixes: 15588227e086 ("ima: Collect modsig") # v5.4+ Fixes: 2fe5d6def167 ("ima: integrity appraisal extension") # v5.14+ Fixes: 4af4662fa4a9 ("integrity: IMA policy") # v3.2+ Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-23evm: Fix build warningsRoberto Sassu2-2/+2
[ Upstream commit 996e0a97ebd7b11cb785794e2a83c20c1add9d92 ] Fix build warnings (function parameters description) for evm_read_protected_xattrs(), evm_set_key() and evm_verifyxattr(). Fixes: 7626676320f3 ("evm: provide a function to set the EVM key from the kernel") # v4.5+ Fixes: 8314b6732ae4 ("ima: Define new template fields xattrnames, xattrlengths and xattrvalues") # v5.14+ Fixes: 2960e6cb5f7c ("evm: additional parameter to pass integrity cache entry 'iint'") # v3.2+ Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-23evm: Complete description of evm_inode_setattr()Roberto Sassu1-0/+2
[ Upstream commit b1de86d4248b273cb12c4cd7d20c08d459519f7d ] Add the description for missing parameters of evm_inode_setattr() to avoid the warning arising with W=n compile option. Fixes: 817b54aa45db ("evm: add evm_inode_setattr to prevent updating an invalid security.evm") # v3.2+ Fixes: c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") # v6.3+ Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11IMA: allow/fix UML buildsRandy Dunlap1-1/+1
commit 644f17412f5acf01a19af9d04a921937a2bc86c6 upstream. UML supports HAS_IOMEM since 0bbadafdc49d (um: allow disabling NO_IOMEM). Current IMA build on UML fails on allmodconfig (with TCG_TPM=m): ld: security/integrity/ima/ima_queue.o: in function `ima_add_template_entry': ima_queue.c:(.text+0x2d9): undefined reference to `tpm_pcr_extend' ld: security/integrity/ima/ima_init.o: in function `ima_init': ima_init.c:(.init.text+0x43f): undefined reference to `tpm_default_chip' ld: security/integrity/ima/ima_crypto.o: in function `ima_calc_boot_aggregate_tfm': ima_crypto.c:(.text+0x1044): undefined reference to `tpm_pcr_read' ld: ima_crypto.c:(.text+0x10d8): undefined reference to `tpm_pcr_read' Modify the IMA Kconfig entry so that it selects TCG_TPM if HAS_IOMEM is set, regardless of the UML Kconfig setting. This updates TCG_TPM from =m to =y and fixes the linker errors. Fixes: f4a0391dfa91 ("ima: fix Kconfig dependencies") Cc: Stable <stable@vger.kernel.org> # v5.14+ Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Fabio Estevam <festevam@gmail.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: linux-um@lists.infradead.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10ima: Align ima_file_mmap() parameters with mmap_file LSM hookRoberto Sassu1-2/+5
commit 4971c268b85e1c7a734a61622fc0813c86e2362e upstream. Commit 98de59bfe4b2f ("take calculation of final prot in security_mmap_file() into a helper") moved the code to update prot, to be the actual protections applied to the kernel, to a new helper called mmap_prot(). However, while without the helper ima_file_mmap() was getting the updated prot, with the helper ima_file_mmap() gets the original prot, which contains the protections requested by the application. A possible consequence of this change is that, if an application calls mmap() with only PROT_READ, and the kernel applies PROT_EXEC in addition, that application would have access to executable memory without having this event recorded in the IMA measurement list. This situation would occur for example if the application, before mmap(), calls the personality() system call with READ_IMPLIES_EXEC as the first argument. Align ima_file_mmap() parameters with those of the mmap_file LSM hook, so that IMA can receive both the requested prot and the final prot. Since the requested protections are stored in a new variable, and the final protections are stored in the existing variable, this effectively restores the original behavior of the MMAP_CHECK hook. Cc: stable@vger.kernel.org Fixes: 98de59bfe4b2 ("take calculation of final prot in security_mmap_file() into a helper") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-12ima: Fix a potential NULL pointer access in ima_restore_measurement_listHuaxin Lu1-1/+4
commit 11220db412edae8dba58853238f53258268bdb88 upstream. In restore_template_fmt, when kstrdup fails, a non-NULL value will still be returned, which causes a NULL pointer access in template_desc_init_fields. Fixes: c7d09367702e ("ima: support restoring multiple template formats") Cc: stable@kernel.org Co-developed-by: Jiaming Li <lijiaming30@huawei.com> Signed-off-by: Jiaming Li <lijiaming30@huawei.com> Signed-off-by: Huaxin Lu <luhuaxin1@huawei.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-12efi: Add iMac Pro 2017 to uefi skip cert quirkAditya Garg1-0/+1
commit 0be56a116220f9e5731a6609e66a11accfe8d8e2 upstream. The iMac Pro 2017 is also a T2 Mac. Thus add it to the list of uefi skip cert. Cc: stable@vger.kernel.org Fixes: 155ca952c7ca ("efi: Do not import certificates from UEFI Secure Boot for T2 Macs") Link: https://lore.kernel.org/linux-integrity/9D46D92F-1381-4F10-989C-1A12CD2FFDD8@live.com/ Signed-off-by: Aditya Garg <gargaditya08@live.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-31ima: Simplify ima_lsm_copy_ruleGUO Zihua1-7/+3
[ Upstream commit d57378d3aa4d864d9e590482602068af1b20c0c5 ] Currently ima_lsm_copy_rule() set the arg_p field of the source rule to NULL, so that the source rule could be freed afterward. It does not make sense for this behavior to be inside a "copy" function. So move it outside and let the caller handle this field. ima_lsm_copy_rule() now produce a shallow copy of the original entry including args_p field. Meaning only the lsm.rule and the rule itself should be freed for the original rule. Thus, instead of calling ima_lsm_free_rule() which frees lsm.rule as well as args_p field, free the lsm.rule directly. Signed-off-by: GUO Zihua <guozihua@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31ima: Fix misuse of dereference of pointer in template_desc_init_fields()Xiu Jianfeng1-2/+2
[ Upstream commit 25369175ce84813dd99d6604e710dc2491f68523 ] The input parameter @fields is type of struct ima_template_field ***, so when allocates array memory for @fields, the size of element should be sizeof(**field) instead of sizeof(*field). Actually the original code would not cause any runtime error, but it's better to make it logically right. Fixes: adf53a778a0a ("ima: new templates management mechanism") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31integrity: Fix memory leakage in keyring allocation error pathGUO Zihua1-1/+5
[ Upstream commit 39419ef7af0916cc3620ecf1ed42d29659109bf3 ] Key restriction is allocated in integrity_init_keyring(). However, if keyring allocation failed, it is not freed, causing memory leaks. Fixes: 2b6aa412ff23 ("KEYS: Use structure to capture key restriction function and data") Signed-off-by: GUO Zihua <guozihua@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31ima: Handle -ESTALE returned by ima_filter_rule_match()GUO Zihua1-9/+32
[ Upstream commit c7423dbdbc9ecef7fff5239d144cad4b9887f4de ] IMA relies on the blocking LSM policy notifier callback to update the LSM based IMA policy rules. When SELinux update its policies, IMA would be notified and starts updating all its lsm rules one-by-one. During this time, -ESTALE would be returned by ima_filter_rule_match() if it is called with a LSM rule that has not yet been updated. In ima_match_rules(), -ESTALE is not handled, and the LSM rule is considered a match, causing extra files to be measured by IMA. Fix it by re-initializing a temporary rule if -ESTALE is returned by ima_filter_rule_match(). The origin rule in the rule list would be updated by the LSM policy notifier callback. Fixes: b16942455193 ("ima: use the lsm policy update notifier") Signed-off-by: GUO Zihua <guozihua@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26ima: fix blocking of security.ima xattrs of unsupported algorithmsMimi Zohar1-4/+8
[ Upstream commit 5926586f291b53cb8a0c9631fc19489be1186e2d ] Limit validating the hash algorithm to just security.ima xattr, not the security.evm xattr or any of the protected EVM security xattrs, nor posix acls. Fixes: 50f742dd9147 ("IMA: block writes of the security.ima xattr with unsupported algorithms") Reported-by: Christian Brauner <brauner@kernel.org> Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-15efi: Correct Macmini DMI match in uefi cert quirkOrlando Chamberlain1-1/+1
commit bab715bdaa9ebf28d99a6d1efb2704a30125e96d upstream. It turns out Apple doesn't capitalise the "mini" in "Macmini" in DMI, which is inconsistent with other model line names. Correct the capitalisation of Macmini in the quirk for skipping loading platform certs on T2 Macs. Currently users get: ------------[ cut here ]------------ [Firmware Bug]: Page fault caused by firmware at PA: 0xffffa30640054000 WARNING: CPU: 1 PID: 8 at arch/x86/platform/efi/quirks.c:735 efi_crash_gracefully_on_page_fault+0x55/0xe0 Modules linked in: CPU: 1 PID: 8 Comm: kworker/u12:0 Not tainted 5.18.14-arch1-2-t2 #1 4535eb3fc40fd08edab32a509fbf4c9bc52d111e Hardware name: Apple Inc. Macmini8,1/Mac-7BA5B2DFE22DDD8C, BIOS 1731.120.10.0.0 (iBridge: 19.16.15071.0.0,0) 04/24/2022 Workqueue: efi_rts_wq efi_call_rts ... ---[ end trace 0000000000000000 ]--- efi: Froze efi_rts_wq and disabled EFI Runtime Services integrity: Couldn't get size: 0x8000000000000015 integrity: MODSIGN: Couldn't get UEFI db list efi: EFI Runtime Services are disabled! integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get UEFI dbx list Fixes: 155ca952c7ca ("efi: Do not import certificates from UEFI Secure Boot for T2 Macs") Cc: stable@vger.kernel.org Cc: Aditya Garg <gargaditya08@live.com> Tested-by: Samuel Jiang <chyishian.jiang@gmail.com> Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29lockdown: Fix kexec lockdown bypass with ima policyEric Snowberg1-0/+4
commit 543ce63b664e2c2f9533d089a4664b559c3e6b5b upstream. The lockdown LSM is primarily used in conjunction with UEFI Secure Boot. This LSM may also be used on machines without UEFI. It can also be enabled when UEFI Secure Boot is disabled. One of lockdown's features is to prevent kexec from loading untrusted kernels. Lockdown can be enabled through a bootparam or after the kernel has booted through securityfs. If IMA appraisal is used with the "ima_appraise=log" boot param, lockdown can be defeated with kexec on any machine when Secure Boot is disabled or unavailable. IMA prevents setting "ima_appraise=log" from the boot param when Secure Boot is enabled, but this does not cover cases where lockdown is used without Secure Boot. To defeat lockdown, boot without Secure Boot and add ima_appraise=log to the kernel command line; then: $ echo "integrity" > /sys/kernel/security/lockdown $ echo "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig" > \ /sys/kernel/security/ima/policy $ kexec -ls unsigned-kernel Add a call to verify ima appraisal is set to "enforce" whenever lockdown is enabled. This fixes CVE-2022-21505. Cc: stable@vger.kernel.org Fixes: 29d3c1c8dfe7 ("kexec: Allow kexec_file() with appropriate IMA policy when locked down") Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: John Haxby <john.haxby@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21ima: Fix potential memory leak in ima_init_crypto()Jianglei Nie1-0/+1
[ Upstream commit 067d2521874135267e681c19d42761c601d503d6 ] On failure to allocate the SHA1 tfm, IMA fails to initialize and exits without freeing the ima_algo_array. Add the missing kfree() for ima_algo_array to avoid the potential memory leak. Signed-off-by: Jianglei Nie <niejianglei2021@163.com> Fixes: 6d94809af6b0 ("ima: Allocate and initialize tfm for each PCR bank") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21ima: force signature verification when CONFIG_KEXEC_SIG is configuredCoiby Xu1-0/+2
[ Upstream commit af16df54b89dee72df253abc5e7b5e8a6d16c11c ] Currently, an unsigned kernel could be kexec'ed when IMA arch specific policy is configured unless lockdown is enabled. Enforce kernel signature verification check in the kexec_file_load syscall when IMA arch specific policy is configured. Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE") Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21ima: Fix a potential integer overflow in ima_appraise_measurementHuaxin Lu1-1/+2
[ Upstream commit d2ee2cfc4aa85ff6a2a3b198a3a524ec54e3d999 ] When the ima-modsig is enabled, the rc passed to evm_verifyxattr() may be negative, which may cause the integer overflow problem. Fixes: 39b07096364a ("ima: Implement support for module-style appended signatures") Signed-off-by: Huaxin Lu <luhuaxin1@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21Revert "evm: Fix memleak in init_desc"Xiu Jianfeng1-5/+2
commit 51dd64bb99e4478fc5280171acd8e1b529eadaf7 upstream. This reverts commit ccf11dbaa07b328fa469415c362d33459c140a37. Commit ccf11dbaa07b ("evm: Fix memleak in init_desc") said there is memleak in init_desc. That may be incorrect, as we can see, tmp_tfm is saved in one of the two global variables hmac_tfm or evm_tfm[hash_algo], then if init_desc is called next time, there is no need to alloc tfm again, so in the error path of kmalloc desc or crypto_shash_init(desc), It is not a problem without freeing tmp_tfm. And also that commit did not reset the global variable to NULL after freeing tmp_tfm and this makes *tfm a dangling pointer which may cause a UAF issue. Reported-by: Guozihua (Scott) <guozihua@huawei.com> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09ima: remove the IMA_TEMPLATE Kconfig optionGUO Zihua1-8/+6
commit 891163adf180bc369b2f11c9dfce6d2758d2a5bd upstream. The original 'ima' measurement list template contains a hash, defined as 20 bytes, and a null terminated pathname, limited to 255 characters. Other measurement list templates permit both larger hashes and longer pathnames. When the "ima" template is configured as the default, a new measurement list template (ima_template=) must be specified before specifying a larger hash algorithm (ima_hash=) on the boot command line. To avoid this boot command line ordering issue, remove the legacy "ima" template configuration option, allowing it to still be specified on the boot command line. The root cause of this issue is that during the processing of ima_hash, we would try to check whether the hash algorithm is compatible with the template. If the template is not set at the moment we do the check, we check the algorithm against the configured default template. If the default template is "ima", then we reject any hash algorithm other than sha1 and md5. For example, if the compiled default template is "ima", and the default algorithm is sha1 (which is the current default). In the cmdline, we put in "ima_hash=sha256 ima_template=ima-ng". The expected behavior would be that ima starts with ima-ng as the template and sha256 as the hash algorithm. However, during the processing of "ima_hash=", "ima_template=" has not been processed yet, and hash_setup would check the configured hash algorithm against the compiled default: ima, and reject sha256. So at the end, the hash algorithm that is actually used will be sha1. With template "ima" removed from the configured default, we ensure that the default tempalte would at least be "ima-ng" which allows for basically any hash algorithm. This change would not break the algorithm compatibility checks for IMA. Fixes: 4286587dccd43 ("ima: add Kconfig default measurement list template") Signed-off-by: GUO Zihua <guozihua@huawei.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09efi: Do not import certificates from UEFI Secure Boot for T2 MacsAditya Garg2-0/+41
commit 155ca952c7ca19aa32ecfb7373a32bbc2e1ec6eb upstream. On Apple T2 Macs, when Linux attempts to read the db and dbx efi variables at early boot to load UEFI Secure Boot certificates, a page fault occurs in Apple firmware code and EFI runtime services are disabled with the following logs: [Firmware Bug]: Page fault caused by firmware at PA: 0xffffb1edc0068000 WARNING: CPU: 3 PID: 104 at arch/x86/platform/efi/quirks.c:735 efi_crash_gracefully_on_page_fault+0x50/0xf0 (Removed some logs from here) Call Trace: <TASK> page_fault_oops+0x4f/0x2c0 ? search_bpf_extables+0x6b/0x80 ? search_module_extables+0x50/0x80 ? search_exception_tables+0x5b/0x60 kernelmode_fixup_or_oops+0x9e/0x110 __bad_area_nosemaphore+0x155/0x190 bad_area_nosemaphore+0x16/0x20 do_kern_addr_fault+0x8c/0xa0 exc_page_fault+0xd8/0x180 asm_exc_page_fault+0x1e/0x30 (Removed some logs from here) ? __efi_call+0x28/0x30 ? switch_mm+0x20/0x30 ? efi_call_rts+0x19a/0x8e0 ? process_one_work+0x222/0x3f0 ? worker_thread+0x4a/0x3d0 ? kthread+0x17a/0x1a0 ? process_one_work+0x3f0/0x3f0 ? set_kthread_struct+0x40/0x40 ? ret_from_fork+0x22/0x30 </TASK> ---[ end trace 1f82023595a5927f ]--- efi: Froze efi_rts_wq and disabled EFI Runtime Services integrity: Couldn't get size: 0x8000000000000015 integrity: MODSIGN: Couldn't get UEFI db list efi: EFI Runtime Services are disabled! integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get UEFI dbx list integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get mokx list integrity: Couldn't get size: 0x80000000 So we avoid reading these UEFI variables and thus prevent the crash. Cc: stable@vger.kernel.org Signed-off-by: Aditya Garg <gargaditya08@live.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08EVM: fix the evm= __setup handler return valueRandy Dunlap1-1/+1
[ Upstream commit f2544f5e6c691679d56bb38637d2f347075b36fa ] __setup() handlers should return 1 if the parameter is handled. Returning 0 causes the entire string to be added to init's environment strings (limited to 32 strings), unnecessarily polluting it. Using the documented string "evm=fix" causes an Unknown parameter message: Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix", will be passed to user space. and that string is added to init's environment string space: Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix With this change, using "evm=fix" acts as expected and an invalid option ("evm=evm") causes a warning to be printed: evm: invalid "evm" mode but init's environment is not polluted with this string, as expected. Fixes: 7102ebcd65c1 ("evm: permit only valid security.evm xattrs to be updated") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-16ima: Do not print policy rule with inactive LSM labelsStefan Berger1-0/+8
commit 89677197ae709eb1ab3646952c44f6a171c9e74c upstream. Before printing a policy rule scan for inactive LSM labels in the policy rule. Inactive LSM labels are identified by args_p != NULL and rule == NULL. Fixes: 483ec26eed42 ("ima: ima/lsm policy rule loading logic bug fixes") Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Cc: <stable@vger.kernel.org> # v5.6+ Acked-by: Christian Brauner <brauner@kernel.org> [zohar@linux.ibm.com: Updated "Fixes" tag] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: Allow template selection with ima_template[_fmt]= after ima_hash=Roberto Sassu1-3/+7
commit bb8e52e4906f148c2faf6656b5106cf7233e9301 upstream. Commit c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") introduced an additional check on the ima_template variable to avoid multiple template selection. Unfortunately, ima_template could be also set by the setup function of the ima_hash= parameter, when it calls ima_template_desc_current(). This causes attempts to choose a new template with ima_template= or with ima_template_fmt=, after ima_hash=, to be ignored. Achieve the goal of the commit mentioned with the new static variable template_setup_done, so that template selection requests after ima_hash= are not ignored. Finally, call ima_init_template_list(), if not already done, to initialize the list of templates before lookup_template_desc() is called. Reported-by: Guo Zihua <guozihua@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Cc: stable@vger.kernel.org Fixes: c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: Remove ima_policy file before directoryStefan Berger1-1/+1
commit f7333b9572d0559e00352a926c92f29f061b4569 upstream. The removal of ima_dir currently fails since ima_policy still exists, so remove the ima_policy file before removing the directory. Fixes: 4af4662fa4a9 ("integrity: IMA policy") Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Cc: <stable@vger.kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: fix reference leak in asymmetric_verify()Eric Biggers1-6/+9
commit 926fd9f23b27ca6587492c3f58f4c7f4cd01dad5 upstream. Don't leak a reference to the key if its algorithm is unknown. Fixes: 947d70597236 ("ima: Support EC keys for signature verification") Cc: <stable@vger.kernel.org> # v5.13+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16integrity: check the return value of audit_log_start()Xiaoke Wang1-0/+2
commit 83230351c523b04ff8a029a4bdf97d881ecb96fc upstream. audit_log_start() returns audit_buffer pointer on success or NULL on error, so it is better to check the return value of it. Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com> Cc: <stable@vger.kernel.org> Reviewed-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18ima: fix deadlock when traversing "ima_default_rules".liqiong1-9/+18
[ Upstream commit eb0782bbdfd0d7c4786216659277c3fd585afc0e ] The current IMA ruleset is identified by the variable "ima_rules" that default to "&ima_default_rules". When loading a custom policy for the first time, the variable is updated to "&ima_policy_rules" instead. That update isn't RCU-safe, and deadlocks are possible. Indeed, some functions like ima_match_policy() may loop indefinitely when traversing "ima_default_rules" with list_for_each_entry_rcu(). When iterating over the default ruleset back to head, if the list head is "ima_default_rules", and "ima_rules" have been updated to "&ima_policy_rules", the loop condition (&entry->list != ima_rules) stays always true, traversing won't terminate, causing a soft lockup and RCU stalls. Introduce a temporary value for "ima_rules" when iterating over the ruleset to avoid the deadlocks. Signed-off-by: liqiong <liqiong@nfschina.com> Reviewed-by: THOBY Simon <Simon.THOBY@viveris.fr> Fixes: 38d859f991f3 ("IMA: policy can now be updated multiple times") Reported-by: kernel test robot <lkp@intel.com> (Fix sparse: incompatible types in comparison expression.) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18evm: mark evm_fixmode as __ro_after_initAustin Kim1-1/+1
commit 32ba540f3c2a7ef61ed5a577ce25069a3d714fc9 upstream. The evm_fixmode is only configurable by command-line option and it is never modified outside initcalls, so declaring it with __ro_after_init is better. Signed-off-by: Austin Kim <austin.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-02Merge tag 'integrity-v5.15' of ↵Linus Torvalds10-65/+316
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity subsystem updates from Mimi Zohar: - Limit the allowed hash algorithms when writing security.ima xattrs or verifying them, based on the IMA policy and the configured hash algorithms. - Return the calculated "critical data" measurement hash and size to avoid code duplication. (Preparatory change for a proposed LSM.) - and a single patch to address a compiler warning. * tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: IMA: reject unknown hash algorithms in ima_get_hash_algo IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms IMA: introduce a new policy option func=SETXATTR_CHECK IMA: add a policy option to restrict xattr hash algorithms on appraisal IMA: add support to restrict the hash algorithms used for file appraisal IMA: block writes of the security.ima xattr with unsupported algorithms IMA: remove the dependency on CRYPTO_MD5 ima: Add digest and digest_len params to the functions to measure a buffer ima: Return int in the functions to measure a buffer ima: Introduce ima_get_current_hash_algo() IMA: remove -Wmissing-prototypes warning
2021-09-01Merge tag 'for-5.15/dm-changes' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Add DM infrastructure for IMA-based remote attestion. These changes are the basis for deploying DM-based storage in a "cloud" that must validate configurations end-users run to maintain trust. These DM changes allow supported DM targets' configurations to be measured via IMA. But the policy and enforcement (of which configurations are valid) is managed by something outside the kernel (e.g. Keylime). - Fix DM crypt scalability regression on systems with many cpus due to percpu_counter spinlock contention in crypt_page_alloc(). - Use in_hardirq() instead of deprecated in_irq() in DM crypt. - Add event counters to DM writecache to allow users to further assess how the writecache is performing. - Various code cleanup in DM writecache's main IO mapping function. * tag 'for-5.15/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm crypt: use in_hardirq() instead of deprecated in_irq() dm ima: update dm documentation for ima measurement support dm ima: update dm target attributes for ima measurements dm ima: add a warning in dm_init if duplicate ima events are not measured dm ima: prefix ima event name related to device mapper with dm_ dm ima: add version info to dm related events in ima log dm ima: prefix dm table hashes in ima log with hash algorithm dm crypt: Avoid percpu_counter spinlock contention in crypt_page_alloc() dm: add documentation for IMA measurement support dm: update target status functions to support IMA measurement dm ima: measure data on device rename dm ima: measure data on table clear dm ima: measure data on device remove dm ima: measure data on device resume dm ima: measure data on table load dm writecache: add event counters dm writecache: report invalid return from writecache_map helpers dm writecache: further writecache_map() cleanup dm writecache: factor out writecache_map_remap_origin() dm writecache: split up writecache_map() to improve code readability
2021-08-27efi: Don't use knowledge about efi_guid_t internalsAndy Shevchenko1-1/+1
When print GUIDs supply pointer to the efi_guid_t (guid_t) type rather its internal members. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-08-24IMA: reject unknown hash algorithms in ima_get_hash_algoTHOBY Simon1-1/+2
The new function validate_hash_algo() assumed that ima_get_hash_algo() always return a valid 'enum hash_algo', but it returned the user-supplied value present in the digital signature without any bounds checks. Update ima_get_hash_algo() to always return a valid hash algorithm, defaulting on 'ima_hash_algo' when the user-supplied value inside the xattr is invalid. Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reported-by: syzbot+e8bafe7b82c739eaf153@syzkaller.appspotmail.com Fixes: 50f742dd9147 ("IMA: block writes of the security.ima xattr with unsupported algorithms") Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithmsTHOBY Simon1-0/+6
SETXATTR_CHECK policy rules assume that any algorithm listed in the 'appraise_algos' flag must be accepted when performing setxattr() on the security.ima xattr. However nothing checks that they are available in the current kernel. A userland application could hash a file with a digest that the kernel wouldn't be able to verify. However, if SETXATTR_CHECK is not in use, the kernel already forbids that xattr write. Verify that algorithms listed in appraise_algos are available to the current kernel and reject the policy update otherwise. This will fix the inconsistency between SETXATTR_CHECK and non-SETXATTR_CHECK behaviors. That filtering is only performed in ima_parse_appraise_algos() when updating policies so that we do not have to pay the price of allocating a hash object every time validate_hash_algo() is called in ima_inode_setxattr(). Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: introduce a new policy option func=SETXATTR_CHECKTHOBY Simon4-17/+96
While users can restrict the accepted hash algorithms for the security.ima xattr file signature when appraising said file, users cannot restrict the algorithms that can be set on that attribute: any algorithm built in the kernel is accepted on a write. Define a new value for the ima policy option 'func' that restricts globally the hash algorithms accepted when writing the security.ima xattr. When a policy contains a rule of the form appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512 only values corresponding to one of these three digest algorithms will be accepted for writing the security.ima xattr. Attempting to write the attribute using another algorithm (or "free-form" data) will be denied with an audit log message. In the absence of such a policy rule, the default is still to only accept hash algorithms built in the kernel (with all the limitations that entails). Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: add a policy option to restrict xattr hash algorithms on appraisalTHOBY Simon1-4/+70
The kernel has the ability to restrict the set of hash algorithms it accepts for the security.ima xattr when it appraises files. Define a new IMA policy rule option "appraise_algos=", using the mentioned mechanism to expose a user-toggable policy knob to opt-in to that restriction and select the desired set of algorithms that must be accepted. When a policy rule uses the 'appraise_algos' option, appraisal of a file referenced by that rule will now fail if the digest algorithm employed to hash the file was not one of those explicitly listed in the option. In its absence, any hash algorithm compiled in the kernel will be accepted. For example, on a system where SELinux is properly deployed, the rule appraise func=BPRM_CHECK obj_type=iptables_exec_t \ appraise_algos=sha256,sha384 will block the execution of iptables if the xattr security.ima of its executables were not hashed with either sha256 or sha384. Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: add support to restrict the hash algorithms used for file appraisalTHOBY Simon5-12/+41
The kernel accepts any hash algorithm as a value for the security.ima xattr. Users may wish to restrict the accepted algorithms to only support strong cryptographic ones. Provide the plumbing to restrict the permitted set of hash algorithms used for verifying file hashes and signatures stored in security.ima xattr. Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: block writes of the security.ima xattr with unsupported algorithmsTHOBY Simon2-4/+47
By default, writes to the extended attributes security.ima will be allowed even if the hash algorithm used for the xattr is not compiled in the kernel (which does not make sense because the kernel would not be able to appraise that file as it lacks support for validating the hash). Prevent and audit writes to the security.ima xattr if the hash algorithm used in the new value is not available in the current kernel. Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-17IMA: remove the dependency on CRYPTO_MD5THOBY Simon1-1/+0
MD5 is a weak digest algorithm that shouldn't be used for cryptographic operation. It hinders the efficiency of a patch set that aims to limit the digests allowed for the extended file attribute namely security.ima. MD5 is no longer a requirement for IMA, nor should it be used there. The sole place where we still use the MD5 algorithm inside IMA is setting the ima_hash algorithm to MD5, if the user supplies 'ima_hash=md5' parameter on the command line. With commit ab60368ab6a4 ("ima: Fallback to the builtin hash algorithm"), setting "ima_hash=md5" fails gracefully when CRYPTO_MD5 is not set: ima: Can not allocate md5 (reason: -2) ima: Allocating md5 failed, going to use default hash algorithm sha256 Remove the CRYPTO_MD5 dependency for IMA. Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> [zohar@linux.ibm.com: include commit number in patch description for stable.] Cc: stable@vger.kernel.org # 4.17 Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-08-10dm ima: measure data on table loadTushar Sugandhi1-0/+1
DM configures a block device with various target specific attributes passed to it as a table. DM loads the table, and calls each target’s respective constructors with the attributes as input parameters. Some of these attributes are critical to ensure the device meets certain security bar. Thus, IMA should measure these attributes, to ensure they are not tampered with, during the lifetime of the device. So that the external services can have high confidence in the configuration of the block-devices on a given system. Some devices may have large tables. And a given device may change its state (table-load, suspend, resume, rename, remove, table-clear etc.) many times. Measuring these attributes each time when the device changes its state will significantly increase the size of the IMA logs. Further, once configured, these attributes are not expected to change unless a new table is loaded, or a device is removed and recreated. Therefore the clear-text of the attributes should only be measured during table load, and the hash of the active/inactive table should be measured for the remaining device state changes. Export IMA function ima_measure_critical_data() to allow measurement of DM device parameters, as well as target specific attributes, during table load. Compute the hash of the inactive table and store it for measurements during future state change. If a load is called multiple times, update the inactive table hash with the hash of the latest populated table. So that the correct inactive table hash is measured when the device transitions to different states like resume, remove, rename, etc. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # leak fix Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-07-23ima: Add digest and digest_len params to the functions to measure a bufferRoberto Sassu6-15/+32
This patch performs the final modification necessary to pass the buffer measurement to callers, so that they provide a functionality similar to ima_file_hash(). It adds the 'digest' and 'digest_len' parameters to ima_measure_critical_data() and process_buffer_measurement(). These functions calculate the digest even if there is no suitable rule in the IMA policy and, in this case, they simply return 1 before generating a new measurement entry. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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