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2022-10-19selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context()GONG, Ruiqi3-5/+6
The following warning was triggered on a hardware environment: SELinux: Converting 162 SID table entries... BUG: sleeping function called from invalid context at __might_sleep+0x60/0x74 0x0 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 5943, name: tar CPU: 7 PID: 5943 Comm: tar Tainted: P O 5.10.0 #1 Call trace: dump_backtrace+0x0/0x1c8 show_stack+0x18/0x28 dump_stack+0xe8/0x15c ___might_sleep+0x168/0x17c __might_sleep+0x60/0x74 __kmalloc_track_caller+0xa0/0x7dc kstrdup+0x54/0xac convert_context+0x48/0x2e4 sidtab_context_to_sid+0x1c4/0x36c security_context_to_sid_core+0x168/0x238 security_context_to_sid_default+0x14/0x24 inode_doinit_use_xattr+0x164/0x1e4 inode_doinit_with_dentry+0x1c0/0x488 selinux_d_instantiate+0x20/0x34 security_d_instantiate+0x70/0xbc d_splice_alias+0x4c/0x3c0 ext4_lookup+0x1d8/0x200 [ext4] __lookup_slow+0x12c/0x1e4 walk_component+0x100/0x200 path_lookupat+0x88/0x118 filename_lookup+0x98/0x130 user_path_at_empty+0x48/0x60 vfs_statx+0x84/0x140 vfs_fstatat+0x20/0x30 __se_sys_newfstatat+0x30/0x74 __arm64_sys_newfstatat+0x1c/0x2c el0_svc_common.constprop.0+0x100/0x184 do_el0_svc+0x1c/0x2c el0_svc+0x20/0x34 el0_sync_handler+0x80/0x17c el0_sync+0x13c/0x140 SELinux: Context system_u:object_r:pssp_rsyslog_log_t:s0:c0 is not valid (left unmapped). It was found that within a critical section of spin_lock_irqsave in sidtab_context_to_sid(), convert_context() (hooked by sidtab_convert_params.func) might cause the process to sleep via allocating memory with GFP_KERNEL, which is problematic. As Ondrej pointed out [1], convert_context()/sidtab_convert_params.func has another caller sidtab_convert_tree(), which is okay with GFP_KERNEL. Therefore, fix this problem by adding a gfp_t argument for convert_context()/sidtab_convert_params.func and pass GFP_KERNEL/_ATOMIC properly in individual callers. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20221018120111.1474581-1-gongruiqi1@huawei.com/ [1] Reported-by: Tan Ninghao <tanninghao1@huawei.com> Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: wrap long BUG() output lines, tweak subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-31selinux: declare read-only parameters constChristian Göttsche4-29/+31
Declare ebitmap, mls_level and mls_context parameters const where they are only read from. This allows callers to supply pointers to const as arguments and increases readability. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-06-15selinux: Add boundary check in put_entry()Xiu Jianfeng1-0/+2
Just like next_entry(), boundary check is necessary to prevent memory out-of-bound access. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-06-14selinux: fix memleak in security_read_state_kernel()Xiu Jianfeng1-1/+8
In this function, it directly returns the result of __security_read_policy without freeing the allocated memory in *data, cause memory leak issue, so free the memory if __security_read_policy failed. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-24Merge tag 'selinux-pr-20220523' of ↵Linus Torvalds3-55/+48
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "We've got twelve patches queued for v5.19, with most being fairly minor. The highlights are below: - The checkreqprot and runtime disable knobs have been deprecated for some time with no active users that we can find. In an effort to move things along we are adding a pause when the knobs are used to help make the deprecation more noticeable in case anyone is still using these hacks in the shadows. - We've added the anonymous inode class name to the AVC audit records when anonymous inodes are involved. This should make writing policy easier when anonymous inodes are involved. - More constification work. This is fairly straightforward and the source of most of the diffstat. - The usual minor cleanups: remove unnecessary assignments, assorted style/checkpatch fixes, kdoc fixes, macro while-loop encapsulations, #include tweaks, etc" * tag 'selinux-pr-20220523' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: security: declare member holding string literal const selinux: log anon inode class name selinux: declare data arrays const selinux: fix indentation level of mls_ops block selinux: include necessary headers in headers selinux: avoid extra semicolon selinux: update parameter documentation selinux: resolve checkpatch errors selinux: don't sleep when CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE is true selinux: checkreqprot is deprecated, add some ssleep() discomfort selinux: runtime disable is deprecated, add some ssleep() discomfort selinux: Remove redundant assignments
2022-05-18selinux: fix bad cleanup on error in hashtab_duplicate()Ondrej Mosnacek1-1/+2
The code attempts to free the 'new' pointer using kmem_cache_free(), which is wrong because this function isn't responsible of freeing it. Instead, the function should free new->htable and clear the contents of *new (to prevent double-free). Cc: stable@vger.kernel.org Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Reported-by: Wander Lairson Costa <wander@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-03selinux: declare data arrays constChristian Göttsche3-20/+18
The arrays for the policy capability names, the initial sid identifiers and the class and permission names are not changed at runtime. Declare them const to avoid accidental modification. Do not override the classmap and the initial sid list in the build time script genheaders. Check flose(3) is successful in genheaders.c, otherwise the written data might be corrupted or incomplete. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: manual merge due to fuzz, minor style tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-03selinux: fix indentation level of mls_ops blockChristian Göttsche1-21/+21
Add one level of indentation to the code block of the label mls_ops in constraint_expr_eval(), to adjust the trailing break; to the parent case: branch. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-03selinux: avoid extra semicolonChristian Göttsche1-9/+9
Wrap macro into `do { } while (0)` to avoid Clang emitting warnings about extra semicolons. Similar to userspace commit https://github.com/SELinuxProject/selinux/commit/9d85aa60d12e468e7fd510c2b5475b5299b71622 Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: whitespace/indenting tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-03selinux: resolve checkpatch errorsChristian Göttsche1-8/+4
Reported by checkpatch: security/selinux/nlmsgtab.c --------------------------- ERROR: that open brace { should be on the previous line #29: FILE: security/selinux/nlmsgtab.c:29: +static const struct nlmsg_perm nlmsg_route_perms[] = +{ ERROR: that open brace { should be on the previous line #97: FILE: security/selinux/nlmsgtab.c:97: +static const struct nlmsg_perm nlmsg_tcpdiag_perms[] = +{ ERROR: that open brace { should be on the previous line #105: FILE: security/selinux/nlmsgtab.c:105: +static const struct nlmsg_perm nlmsg_xfrm_perms[] = +{ ERROR: that open brace { should be on the previous line #134: FILE: security/selinux/nlmsgtab.c:134: +static const struct nlmsg_perm nlmsg_audit_perms[] = +{ security/selinux/ss/policydb.c ------------------------------ ERROR: that open brace { should be on the previous line #318: FILE: security/selinux/ss/policydb.c:318: +static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) = +{ ERROR: that open brace { should be on the previous line #674: FILE: security/selinux/ss/policydb.c:674: +static int (*index_f[SYM_NUM]) (void *key, void *datum, void *datap) = +{ ERROR: that open brace { should be on the previous line #1643: FILE: security/selinux/ss/policydb.c:1643: +static int (*read_f[SYM_NUM]) (struct policydb *p, struct symtab *s, void *fp) = +{ ERROR: that open brace { should be on the previous line #3246: FILE: security/selinux/ss/policydb.c:3246: + void *datap) = +{ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-04-04selinux: Remove redundant assignmentsMichal Orzel1-1/+0
Get rid of redundant assignments which end up in values not being read either because they are overwritten or the function ends. Reported by clang-tidy [deadcode.DeadStores] Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-03-22Merge tag 'selinux-pr-20220321' of ↵Linus Torvalds8-21/+13
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "We've got a number of SELinux patches queued up, the highlights are: - Fixup the security_fs_context_parse_param() LSM hook so it executes all of the LSM hook implementations unless a serious error occurs. We also correct the SELinux hook implementation so that it returns zero on success. - In addition to a few SELinux mount option parsing fixes, we simplified the parsing by moving it earlier in the process. The logic was that it was unlikely an admin/user would use the new mount API and not have the policy loaded before passing the SELinux options. - Properly fixed the LSM/SELinux/SCTP hooks with the addition of the security_sctp_assoc_established() hook. This work was done in conjunction with the netdev folks and should complete the move of the SCTP labeling from the endpoints to the associations. - Fixed a variety of sparse warnings caused by changes in the "__rcu" markings of some core kernel structures. - Ensure we access the superblock's LSM security blob using the stacking-safe accessors. - Added the ability for the kernel to always allow FIOCLEX and FIONCLEX if the "ioctl_skip_cloexec" policy capability is specified. - Various constifications improvements, type casting improvements, additional return value checks, and dead code/parameter removal. - Documentation fixes" * tag 'selinux-pr-20220321' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (23 commits) selinux: shorten the policy capability enum names docs: fix 'make htmldocs' warning in SCTP.rst selinux: allow FIOCLEX and FIONCLEX with policy capability selinux: use correct type for context length selinux: drop return statement at end of void functions security: implement sctp_assoc_established hook in selinux security: add sctp_assoc_established hook selinux: parse contexts for mount options early selinux: various sparse fixes selinux: try to use preparsed sid before calling parse_sid() selinux: Fix selinux_sb_mnt_opts_compat() LSM: general protection fault in legacy_parse_param selinux: fix a type cast problem in cred_init_security() selinux: drop unused macro selinux: simplify cred_init_security selinux: do not discard const qualifier in cast selinux: drop unused parameter of avtab_insert_node selinux: drop cast to same type selinux: enclose macro arguments in parenthesis selinux: declare name parameter of hash_eval const ...
2022-02-18selinux: drop return statement at end of void functionsChristian Göttsche4-6/+0
Those return statements at the end of a void function are redundant. Reported by clang-tidy [readability-redundant-control-flow] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-02-02selinux: fix double free of cond_list on error pathsVratislav Bendel1-1/+2
On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop. Also consistently reset the cond_list pointer to NULL after freeing. Cc: stable@vger.kernel.org Signed-off-by: Vratislav Bendel <vbendel@redhat.com> [PM: fix line lengths in the description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-27selinux: drop unused macroChristian Göttsche1-2/+0
The macro _DEBUG_HASHES is nowhere used. The configuration DEBUG_HASHES enables debugging of the SELinux hash tables, but the with an underscore prefixed macro definition has no direct impact or any documentation. Reported by clang [-Wunused-macros] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-26selinux: drop unused parameter of avtab_insert_nodeChristian Göttsche1-3/+3
The parameter cur is not used in avtab_insert_node(). Reported by clang [-Wunused-parameter] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-26selinux: drop cast to same typeChristian Göttsche1-1/+1
Both the lvalue scontextp and rvalue scontext are of the type char*. Drop the redundant explicit cast not needed since commit 9a59daa03df7 ("SELinux: fix sleeping allocation in security_context_to_sid"), where the type of scontext changed from const char* to char*. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-26selinux: enclose macro arguments in parenthesisChristian Göttsche2-5/+5
Enclose the macro arguments in parenthesis to avoid potential evaluation order issues. Note the xperm and ebitmap macros are still not side-effect safe due to double evaluation. Reported by clang-tidy [bugprone-macro-parentheses] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-26selinux: declare name parameter of hash_eval constChristian Göttsche1-1/+1
String literals are passed as second argument to hash_eval(). Also the parameter is already declared const in the DEBUG_HASHES configuration. Reported by clang [-Wwrite-strings]: security/selinux/ss/policydb.c:1881:26: error: passing 'const char [8]' to parameter of type 'char *' discards qualifiers hash_eval(&p->range_tr, rangetr); ^~~~~~~~~ security/selinux/ss/policydb.c:707:55: note: passing argument to parameter 'hash_name' here static inline void hash_eval(struct hashtab *h, char *hash_name) ^ security/selinux/ss/policydb.c:2099:32: error: passing 'const char [11]' to parameter of type 'char *' discards qualifiers hash_eval(&p->filename_trans, filenametr); ^~~~~~~~~~~~ security/selinux/ss/policydb.c:707:55: note: passing argument to parameter 'hash_name' here static inline void hash_eval(struct hashtab *h, char *hash_name) ^ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: line wrapping in description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-26selinux: declare path parameters of _genfs_sid constChristian Göttsche1-3/+3
The path parameter is only read from in security_genfs_sid(), selinux_policy_genfs_sid() and __security_genfs_sid(). Since a string literal is passed as argument, declare the parameter const. Also align the parameter names in the declaration and definition. Reported by clang [-Wwrite-strings]: security/selinux/hooks.c:553:60: error: passing 'const char [2]' to parameter of type 'char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers] rc = security_genfs_sid(&selinux_state, ... , /, ^~~ ./security/selinux/include/security.h:389:36: note: passing argument to parameter 'name' here const char *fstype, char *name, u16 sclass, ^ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: wrapped description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-01-12Merge tag 'selinux-pr-20220110' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "Nothing too significant, but five SELinux patches for v5.17 that do the following: - Harden the code through additional use of the struct_size() macro - Plug some memory leaks - Clean up the code via removal of the security_add_mnt_opt() LSM hook and minor tweaks to selinux_add_opt() - Rename security_task_getsecid_subj() to better reflect its actual behavior/use - now called security_current_getsecid_subj()" * tag 'selinux-pr-20220110' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: minor tweaks to selinux_add_opt() selinux: fix potential memleak in selinux_add_opt() security,selinux: remove security_add_mnt_opt() selinux: Use struct_size() helper in kmalloc() lsm: security_task_getsecid_subj() -> security_current_getsecid_subj()
2021-12-06selinux: Use struct_size() helper in kmalloc()Xiu Jianfeng1-1/+1
Make use of struct_size() helper instead of an open-coded calculation. Link: https://github.com/KSPP/linux/issues/160 Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-11-20selinux: fix NULL-pointer dereference when hashtab allocation failsOndrej Mosnacek1-5/+12
When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails. Cc: stable@vger.kernel.org Fixes: 03414a49ad5f ("selinux: do not allocate hashtabs dynamically") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-10-13selinux: fix all of the W=1 build warningsPaul Moore3-4/+15
There were a number of places in the code where the function definition did not match the associated comment block as well at least one file where the appropriate header files were not included (missing function declaration/prototype); this patch fixes all of these issue such that building the SELinux code with "W=1" is now warning free. % make W=1 security/selinux/ Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-10-12selinux: fix race condition when computing ocontext SIDsOndrej Mosnacek1-85/+77
Current code contains a lot of racy patterns when converting an ocontext's context structure to an SID. This is being done in a "lazy" fashion, such that the SID is looked up in the SID table only when it's first needed and then cached in the "sid" field of the ocontext structure. However, this is done without any locking or memory barriers and is thus unsafe. Between commits 24ed7fdae669 ("selinux: use separate table for initial SID lookup") and 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"), this race condition lead to an actual observable bug, because a pointer to the shared sid field was passed directly to sidtab_context_to_sid(), which was using this location to also store an intermediate value, which could have been read by other threads and interpreted as an SID. In practice this caused e.g. new mounts to get a wrong (seemingly random) filesystem context, leading to strange denials. This bug has been spotted in the wild at least twice, see [1] and [2]. Fix the race condition by making all the racy functions use a common helper that ensures the ocontext::sid accesses are made safely using the appropriate SMP constructs. Note that security_netif_sid() was populating the sid field of both contexts stored in the ocontext, but only the first one was actually used. The SELinux wiki's documentation on the "netifcon" policy statement [3] suggests that using only the first context is intentional. I kept only the handling of the first context here, as there is really no point in doing the SID lookup for the unused one. I wasn't able to reproduce the bug mentioned above on any kernel that includes commit 66f8e2f03c02, even though it has been reported that the issue occurs with that commit, too, just less frequently. Thus, I wasn't able to verify that this patch fixes the issue, but it makes sense to avoid the race condition regardless. [1] https://github.com/containers/container-selinux/issues/89 [2] https://lists.fedoraproject.org/archives/list/selinux@lists.fedoraproject.org/thread/6DMTAMHIOAOEMUAVTULJD45JZU7IBAFM/ [3] https://selinuxproject.org/page/NetworkStatements#netifcon Cc: stable@vger.kernel.org Cc: Xinjie Zheng <xinjie@google.com> Reported-by: Sujithra Periasamy <sujithra@google.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-08-31Merge tag 'selinux-pr-20210830' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux update from Paul Moore: "We've got an unusually small SELinux pull request for v5.15 that consists of only one (?!) patch that is really pretty minor when you look at it. Unsurprisingly it passes all of our tests and merges cleanly on top of your tree right now, please merge this for v5.15" * tag 'selinux-pr-20210830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: return early for possible NULL audit buffers
2021-08-02selinux: correct the return value when loads initial sidsXiu Jianfeng1-6/+4
It should not return 0 when SID 0 is assigned to isids. This patch fixes it. Cc: stable@vger.kernel.org Fixes: e3e0b582c321a ("selinux: remove unused initial SIDs and improve handling") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> [PM: remove changelog from description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-07-14selinux: return early for possible NULL audit buffersAustin Kim1-0/+2
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 <austin.kim@lge.com> [PM: tweak subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
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 <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-05-11selinux: Remove redundant assignment to rcJiapeng Chong2-5/+0
Variable rc is set to '-EINVAL' but this value is never read as it is overwritten or not used later on, hence it is a redundant assignment and can be removed. Cleans up the following clang-analyzer warning: security/selinux/ss/services.c:2103:3: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]. security/selinux/ss/services.c:2079:2: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]. security/selinux/ss/services.c:2071:2: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]. security/selinux/ss/services.c:2062:2: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]. security/selinux/ss/policydb.c:2592:3: warning: Value stored to 'rc' is never read [clang-analyzer-deadcode.DeadStores]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-05-11selinux: constify some avtab function argumentsOndrej Mosnacek3-21/+26
This makes the code a bit easier to reason about. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-05-11selinux: simplify duplicate_policydb_cond_list() by using kmemdup()Ondrej Mosnacek1-5/+6
We can do the allocation + copying of expr.nodes in one go using kmemdup(). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-05-02Merge tag 'landlock_v34' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull Landlock LSM from James Morris: "Add Landlock, a new LSM from Mickaël Salaün. Briefly, Landlock provides for unprivileged application sandboxing. From Mickaël's cover letter: "The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]" The cover letter and v34 posting is here: https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/ See also: https://landlock.io/ This code has had extensive design discussion and review over several years" Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1] Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2] * tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: landlock: Enable user space to infer supported features landlock: Add user and kernel documentation samples/landlock: Add a sandbox manager example selftests/landlock: Add user space tests landlock: Add syscall implementations arch: Wire up Landlock syscalls fs,security: Add sb_delete hook landlock: Support filesystem access-control LSM: Infrastructure management of the superblock landlock: Add ptrace restrictions landlock: Set up the security framework and manage credentials landlock: Add ruleset and domain management landlock: Add object management
2021-04-27Merge tag 'selinux-pr-20210426' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: - Add support for measuring the SELinux state and policy capabilities using IMA. - A handful of SELinux/NFS patches to compare the SELinux state of one mount with a set of mount options. Olga goes into more detail in the patch descriptions, but this is important as it allows more flexibility when using NFS and SELinux context mounts. - Properly differentiate between the subjective and objective LSM credentials; including support for the SELinux and Smack. My clumsy attempt at a proper fix for AppArmor didn't quite pass muster so John is working on a proper AppArmor patch, in the meantime this set of patches shouldn't change the behavior of AppArmor in any way. This change explains the bulk of the diffstat beyond security/. - Fix a problem where we were not properly terminating the permission list for two SELinux object classes. * tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: add proper NULL termination to the secclass_map permissions smack: differentiate between subjective and objective task credentials selinux: clarify task subjective and objective credentials lsm: separate security_task_getsecid() into subjective and objective variants nfs: account for selinux security context when deciding to share superblock nfs: remove unneeded null check in nfs_fill_super() lsm,selinux: add new hook to compare new mount to an existing mount selinux: fix misspellings using codespell tool selinux: fix misspellings using codespell tool selinux: measure state and policy capabilities selinux: Allow context mounts for unpriviliged overlayfs
2021-04-22LSM: Infrastructure management of the superblockCasey Schaufler1-1/+2
Move management of the superblock->sb_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules, the modules tell the infrastructure how much space is required, and the space is allocated there. Cc: John Johansen <john.johansen@canonical.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210422154123.13086-6-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-04-09Merge tag 'selinux-pr-20210409' of ↵Linus Torvalds6-112/+185
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux fixes from Paul Moore: "Three SELinux fixes. These fix known problems relating to (re)loading SELinux policy or changing the policy booleans, and pass our test suite without problem" * tag 'selinux-pr-20210409' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: fix race between old and new sidtab selinux: fix cond_list corruption when changing booleans selinux: make nslot handling in avtab more robust
2021-04-08selinux: fix race between old and new sidtabOndrej Mosnacek3-37/+145
Since commit 1b8b31a2e612 ("selinux: convert policy read-write lock to RCU"), there is a small window during policy load where the new policy pointer has already been installed, but some threads may still be holding the old policy pointer in their read-side RCU critical sections. This means that there may be conflicting attempts to add a new SID entry to both tables via sidtab_context_to_sid(). See also (and the rest of the thread): https://lore.kernel.org/selinux/CAFqZXNvfux46_f8gnvVvRYMKoes24nwm2n3sPbMjrB8vKTW00g@mail.gmail.com/ Fix this by installing the new policy pointer under the old sidtab's spinlock along with marking the old sidtab as "frozen". Then, if an attempt to add new entry to a "frozen" sidtab is detected, make sidtab_context_to_sid() return -ESTALE to indicate that a new policy has been installed and that the caller will have to abort the policy transaction and try again after re-taking the policy pointer (which is guaranteed to be a newer policy). This requires adding a retry-on-ESTALE logic to all callers of sidtab_context_to_sid(), but fortunately these are easy to determine and aren't that many. This seems to be the simplest solution for this problem, even if it looks somewhat ugly. Note that other places in the kernel (e.g. do_mknodat() in fs/namei.c) use similar stale-retry patterns, so I think it's reasonable. Cc: stable@vger.kernel.org Fixes: 1b8b31a2e612 ("selinux: convert policy read-write lock to RCU") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-04-02selinux: fix cond_list corruption when changing booleansOndrej Mosnacek3-69/+33
Currently, duplicate_policydb_cond_list() first copies the whole conditional avtab and then tries to link to the correct entries in cond_dup_av_list() using avtab_search(). However, since the conditional avtab may contain multiple entries with the same key, this approach often fails to find the right entry, potentially leading to wrong rules being activated/deactivated when booleans are changed. To fix this, instead start with an empty conditional avtab and add the individual entries one-by-one while building the new av_lists. This approach leads to the correct result, since each entry is present in the av_lists exactly once. The issue can be reproduced with Fedora policy as follows: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True # setsebool ftpd_anon_write=off ftpd_connect_all_unreserved=off ftpd_connect_db=off ftpd_full_access=off On fixed kernels, the sesearch output is the same after the setsebool command: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True While on the broken kernels, it will be different: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True While there, also simplify the computation of nslots. This changes the nslots values for nrules 2 or 3 to just two slots instead of 4, which makes the sequence more consistent. Cc: stable@vger.kernel.org Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-04-02selinux: make nslot handling in avtab more robustOndrej Mosnacek1-10/+11
1. Make sure all fileds are initialized in avtab_init(). 2. Slightly refactor avtab_alloc() to use the above fact. 3. Use h->nslot == 0 as a sentinel in the access functions to prevent dereferencing h->htable when it's not allocated. Cc: stable@vger.kernel.org Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-22Merge tag 'selinux-pr-20210322' of ↵Linus Torvalds1-24/+39
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux fixes from Paul Moore: "Three SELinux patches: - Fix a problem where a local variable is used outside its associated function. Thankfully this can only be triggered by reloading the SELinux policy, which is a restricted operation for other obvious reasons. - Fix some incorrect, and inconsistent, audit and printk messages when loading the SELinux policy. All three patches are relatively minor and have been through our testing with no failures" * tag 'selinux-pr-20210322' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinuxfs: unify policy load error reporting selinux: fix variable scope issue in live sidtab conversion selinux: don't log MAC_POLICY_LOAD record on failed policy load
2021-03-19selinux: fix variable scope issue in live sidtab conversionOndrej Mosnacek1-24/+39
Commit 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") moved the selinux_policy_commit() call out of security_load_policy() into sel_write_load(), which caused a subtle yet rather serious bug. The problem is that security_load_policy() passes a reference to the convert_params local variable to sidtab_convert(), which stores it in the sidtab, where it may be accessed until the policy is swapped over and RCU synchronized. Before 02a52c5c8c3b, selinux_policy_commit() was called directly from security_load_policy(), so the convert_params pointer remained valid all the way until the old sidtab was destroyed, but now that's no longer the case and calls to sidtab_context_to_sid() on the old sidtab after security_load_policy() returns may cause invalid memory accesses. This can be easily triggered using the stress test from commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance"): ``` function rand_cat() { echo $(( $RANDOM % 1024 )) } function do_work() { while true; do echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \ >/sys/fs/selinux/context 2>/dev/null || true done } do_work >/dev/null & do_work >/dev/null & do_work >/dev/null & while load_policy; do echo -n .; sleep 0.1; done kill %1 kill %2 kill %3 ``` Fix this by allocating the temporary sidtab convert structures dynamically and passing them among the selinux_policy_{load,cancel,commit} functions. Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") Cc: stable@vger.kernel.org Tested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: merge fuzz in security.h and services.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-09selinux: fix misspellings using codespell toolXiong Zhenwu1-1/+1
A typo is found out by codespell tool in 16th line of hashtab.c $ codespell ./security/selinux/ss/ ./hashtab.c:16: rouding ==> rounding Fix a typo found by codespell. Signed-off-by: Xiong Zhenwu <xiong.zhenwu@zte.com.cn> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-09selinux: measure state and policy capabilitiesLakshmi Ramasubramanian1-1/+1
SELinux stores the configuration state and the policy capabilities in kernel memory. Changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring this data through IMA subsystem provides a tamper-resistant way for an attestation service to remotely validate it at runtime. Measure the configuration state and policy capabilities by calling the IMA hook ima_measure_critical_data(). To enable SELinux data measurement, the following steps are required: 1, Add "ima_policy=critical_data" to the kernel command line arguments to enable measuring SELinux data at boot time. For example, BOOT_IMAGE=/boot/vmlinuz-5.11.0-rc3+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data 2, Add the following rule to /etc/ima/ima-policy measure func=CRITICAL_DATA label=selinux Sample measurement of SELinux state and policy capabilities: 10 2122...65d8 ima-buf sha256:13c2...1292 selinux-state 696e...303b Execute the following command to extract the measured data from the IMA's runtime measurements list: grep "selinux-state" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 | xxd -r -p The output should be a list of key-value pairs. For example, initialized=1;enforcing=0;checkreqprot=1;network_peer_controls=1;open_perms=1;extended_socket_class=1;always_check_network=0;cgroup_seclabel=1;nnp_nosuid_transition=1;genfs_seclabel_symlinks=0; To verify the measurement is consistent with the current SELinux state reported on the system, compare the integer values in the following files with those set in the IMA measurement (using the following commands): - cat /sys/fs/selinux/enforce - cat /sys/fs/selinux/checkreqprot - cat /sys/fs/selinux/policy_capabilities/[capability_file] Note that the actual verification would be against an expected state and done on a separate system (likely an attestation server) requiring "initialized=1;enforcing=1;checkreqprot=0;" for a secure state and then whatever policy capabilities are actually set in the expected policy (which can be extracted from the policy itself via seinfo, for example). Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Suggested-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-02-22Merge tag 'integrity-v5.12' of ↵Linus Torvalds1-9/+55
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull IMA updates from Mimi Zohar: "New is IMA support for measuring kernel critical data, as per usual based on policy. The first example measures the in memory SELinux policy. The second example measures the kernel version. In addition are four bug fixes to address memory leaks and a missing 'static' function declaration" * tag 'integrity-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Make function integrity_add_key() static ima: Free IMA measurement buffer after kexec syscall ima: Free IMA measurement buffer on error IMA: Measure kernel version in early boot selinux: include a consumer of the new IMA critical data hook IMA: define a builtin critical data measurement policy IMA: extend critical data hook to limit the measurement based on a label IMA: limit critical data measurement based on a label IMA: add policy rule to measure critical data IMA: define a hook to measure kernel integrity critical data IMA: add support to measure buffer data hash IMA: generalize keyring specific measurement constructs evm: Fix memleak in init_desc
2021-01-15selinux: include a consumer of the new IMA critical data hookLakshmi Ramasubramanian1-9/+55
SELinux stores the active policy in memory, so the changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring in-memory SELinux policy through IMA subsystem provides a secure way for the attestation service to remotely validate the policy contents at runtime. Measure the hash of the loaded policy by calling the IMA hook ima_measure_critical_data(). Since the size of the loaded policy can be large (several MB), measure the hash of the policy instead of the entire policy to avoid bloating the IMA log entry. To enable SELinux data measurement, the following steps are required: 1, Add "ima_policy=critical_data" to the kernel command line arguments to enable measuring SELinux data at boot time. For example, BOOT_IMAGE=/boot/vmlinuz-5.10.0-rc1+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data 2, Add the following rule to /etc/ima/ima-policy measure func=CRITICAL_DATA label=selinux Sample measurement of the hash of SELinux policy: To verify the measured data with the current SELinux policy run the following commands and verify the output hash values match. sha256sum /sys/fs/selinux/policy | cut -d' ' -f 1 grep "selinux-policy-hash" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 Note that the actual verification of SELinux policy would require loading the expected policy into an identical kernel on a pristine/known-safe system and run the sha256sum /sys/kernel/selinux/policy there to get the expected hash. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-01-12selinux: mark some global variables __ro_after_initOndrej Mosnacek3-4/+4
All of these are never modified outside initcalls, so they can be __ro_after_init. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-12selinux: drop the unnecessary aurule_callback variableOndrej Mosnacek1-7/+3
Its value is actually not changed anywhere, so it can be substituted for a direct call to audit_update_lsm_rules(). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-10-28selinux: allow dontauditx and auditallowx rules to take effect without allowxbauen11-3/+1
This allows for dontauditing very specific ioctls e.g. TCGETS without dontauditing every ioctl or granting additional permissions. Now either an allowx, dontauditx or auditallowx rules enables checking for extended permissions. Signed-off-by: Jonathan Hettwer <j2468h@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-10-14Merge tag 'selinux-pr-20201012' of ↵Linus Torvalds10-365/+793
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "A decent number of SELinux patches for v5.10, twenty two in total. The highlights are listed below, but all of the patches pass our test suite and merge cleanly. - A number of changes to how the SELinux policy is loaded and managed inside the kernel with the goal of improving the atomicity of a SELinux policy load operation. These changes account for the bulk of the diffstat as well as the patch count. A special thanks to everyone who contributed patches and fixes for this work. - Convert the SELinux policy read-write lock to RCU. - A tracepoint was added for audited SELinux access control events; this should help provide a more unified backtrace across kernel and userspace. - Allow the removal of security.selinux xattrs when a SELinux policy is not loaded. - Enable policy capabilities in SELinux policies created with the scripts/selinux/mdp tool. - Provide some "no sooner than" dates for the SELinux checkreqprot sysfs deprecation" * tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (22 commits) selinux: provide a "no sooner than" date for the checkreqprot removal selinux: Add helper functions to get and set checkreqprot selinux: access policycaps with READ_ONCE/WRITE_ONCE selinux: simplify away security_policydb_len() selinux: move policy mutex to selinux_state, use in lockdep checks selinux: fix error handling bugs in security_load_policy() selinux: convert policy read-write lock to RCU selinux: delete repeated words in comments selinux: add basic filtering for audit trace events selinux: add tracepoint on audited events selinux: Create new booleans and class dirs out of tree selinux: Standardize string literal usage for selinuxfs directory names selinux: Refactor selinuxfs directory populating functions selinux: Create function for selinuxfs directory cleanup selinux: permit removing security.selinux xattr before policy load selinux: fix memdup.cocci warnings selinux: avoid dereferencing the policy prior to initialization selinux: fix allocation failure check on newpolicy->sidtab selinux: refactor changing booleans selinux: move policy commit after updating selinuxfs ...
2020-09-11selinux: access policycaps with READ_ONCE/WRITE_ONCEStephen Smalley1-1/+2
Use READ_ONCE/WRITE_ONCE for all accesses to the selinux_state.policycaps booleans to prevent compiler mischief. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 20:29:32 +0300