kernel/linux.git/include/linux/lsm_hooks.h, branch v5.10.258

lsm: make security_socket_getpeersec_stream() sockptr_t safe

2024-03-15T14:48:20+00:00

[ Upstream commit b10b9c342f7571f287fd422be5d5c0beb26ba974 ] Commit 4ff09db1b79b ("bpf: net: Change sk_getsockopt() to take the sockptr_t argument") made it possible to call sk_getsockopt() with both user and kernel address space buffers through the use of the sockptr_t type. Unfortunately at the time of conversion the security_socket_getpeersec_stream() LSM hook was written to only accept userspace buffers, and in a desire to avoid having to change the LSM hook the commit author simply passed the sockptr_t's userspace buffer pointer. Since the only sk_getsockopt() callers at the time of conversion which used kernel sockptr_t buffers did not allow SO_PEERSEC, and hence the security_socket_getpeersec_stream() hook, this was acceptable but also very fragile as future changes presented the possibility of silently passing kernel space pointers to the LSM hook. There are several ways to protect against this, including careful code review of future commits, but since relying on code review to catch bugs is a recipe for disaster and the upstream eBPF maintainer is "strongly against defensive programming", this patch updates the LSM hook, and all of the implementations to support sockptr_t and safely handle both user and kernel space buffers. Acked-by: Casey Schaufler Acked-by: John Johansen Signed-off-by: Paul Moore Stable-dep-of: 5a287d3d2b9d ("lsm: fix default return value of the socket_getpeersec_*() hooks") Signed-off-by: Sasha Levin

lsm,selinux: pass flowi_common instead of flowi to the LSM hooks

2022-06-09T08:21:09+00:00

[ Upstream commit 3df98d79215ace13d1e91ddfc5a67a0f5acbd83f ] As pointed out by Herbert in a recent related patch, the LSM hooks do not have the necessary address family information to use the flowi struct safely. As none of the LSMs currently use any of the protocol specific flowi information, replace the flowi pointers with pointers to the address family independent flowi_common struct. Reported-by: Herbert Xu Acked-by: James Morris Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

binder: use cred instead of task for selinux checks

2021-11-18T13:03:36+00:00

commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn Signed-off-by: Todd Kjos Acked-by: Casey Schaufler Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49+00:00

Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Linus Torvalds

LSM: Add "contents" flag to kernel_read_file hook

2020-10-05T11:37:03+00:00

As with the kernel_load_data LSM hook, add a "contents" flag to the kernel_read_file LSM hook that indicates whether the LSM can expect a matching call to the kernel_post_read_file LSM hook with the full contents of the file. With the coming addition of partial file read support for kernel_read_file*() API, the LSM will no longer be able to always see the entire contents of a file during the read calls. For cases where the LSM must read examine the complete file contents, it will need to do so on its own every time the kernel_read_file hook is called with contents=false (or reject such cases). Adjust all existing LSMs to retain existing behavior. Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

LSM: Introduce kernel_post_load_data() hook

2020-10-05T11:37:03+00:00

There are a few places in the kernel where LSMs would like to have visibility into the contents of a kernel buffer that has been loaded or read. While security_kernel_post_read_file() (which includes the buffer) exists as a pairing for security_kernel_read_file(), no such hook exists to pair with security_kernel_load_data(). Earlier proposals for just using security_kernel_post_read_file() with a NULL file argument were rejected (i.e. "file" should always be valid for the security_..._file hooks, but it appears at least one case was left in the kernel during earlier refactoring. (This will be fixed in a subsequent patch.) Since not all cases of security_kernel_load_data() can have a single contiguous buffer made available to the LSM hook (e.g. kexec image segments are separately loaded), there needs to be a way for the LSM to reason about its expectations of the hook coverage. In order to handle this, add a "contents" argument to the "kernel_load_data" hook that indicates if the newly added "kernel_post_load_data" hook will be called with the full contents once loaded. That way, LSMs requiring full contents can choose to unilaterally reject "kernel_load_data" with contents=false (which is effectively the existing hook coverage), but when contents=true they can allow it and later evaluate the "kernel_post_load_data" hook once the buffer is loaded. With this change, LSMs can gain coverage over non-file-backed data loads (e.g. init_module(2) and firmware userspace helper), which will happen in subsequent patches. Additionally prepare IMA to start processing these cases. Signed-off-by: Kees Cook Reviewed-by: KP Singh Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2020-08-11T21:30:36+00:00

Pull security subsystem updates from James Morris: "A couple of minor documentation updates only for this release" * tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: LSM: drop duplicated words in header file comments Replace HTTP links with HTTPS ones: security

LSM: drop duplicated words in header file comments

2020-08-06T19:00:17+00:00

Drop the doubled words "the" and "and" in comments. Signed-off-by: Randy Dunlap Acked-by: Serge Hallyn Cc: linux-security-module@vger.kernel.org Signed-off-by: James Morris

Merge tag 'LSM-add-setgid-hook-5.8-author-fix' of git://github.com/micah-morton/linux

2020-06-14T18:39:31+00:00

Pull SafeSetID update from Micah Morton: "Add additional LSM hooks for SafeSetID SafeSetID is capable of making allow/deny decisions for set*uid calls on a system, and we want to add similar functionality for set*gid calls. The work to do that is not yet complete, so probably won't make it in for v5.8, but we are looking to get this simple patch in for v5.8 since we have it ready. We are planning on the rest of the work for extending the SafeSetID LSM being merged during the v5.9 merge window" * tag 'LSM-add-setgid-hook-5.8-author-fix' of git://github.com/micah-morton/linux: security: Add LSM hooks to set*gid syscalls

security: Add LSM hooks to set*gid syscalls

2020-06-14T17:52:02+00:00

The SafeSetID LSM uses the security_task_fix_setuid hook to filter set*uid() syscalls according to its configured security policy. In preparation for adding analagous support in the LSM for set*gid() syscalls, we add the requisite hook here. Tested by putting print statements in the security_task_fix_setgid hook and seeing them get hit during kernel boot. Signed-off-by: Thomas Cedeno Signed-off-by: Micah Morton