e00923f0bc
This migrates ksud execution decision-making to bprm_check_security. This requires passing proper argv and envp to a modified _ksud handler aptly named 'ksu_handle_bprm_ksud'. Introduces: int ksu_handle_bprm_ksud(const char *filename, const char *argv1, const char *envp, size_t envp_len) which is adapted from: int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr, struct user_arg_ptr *argv, struct user_arg_ptr *envp, int *flags) ksu_handle_bprm_ksud handles all the decision making, it decides when it is time to apply_kernelsu_rules depending if it sees "second_stage". For LSM hook, turns out we can pull out argv and envp from mm_struct. The code in here explains itself on how to do it. whole blob exists on arg_start to arg_end, so we just pull it out and grab next array after the first null terminator. as for envp, we pass the pointer then hunt for it when needed My reasoning on adding a fallback on usercopy is that on some devices a fault happens, and it copies garbled data. On my creation of this, I actually had to lock that _nofault copy on a spinlock as a way to mimic preempt_disable/enable without actually doing it. As per user reports, no failed _nofault copies anyway but we have-to-have a fallback for resilience. References: - old version16efcd8193e- old version237d5938e66- bad usercopy #21 This now provides a small helper function, ksu_copy_from_user_retry, which explains itself. First we attempt a _nofault copy, if that fails, we try plain. With that, It also provides an inlined copy_from_user_nofault for < 5.8. While using strncpy_from_user_nofault was considered, this wont do, this will only copy up to the first \0. devlog:16e5dce9e7...16c1f5f52128642e60d7...728de0c571References: https://elixir.bootlin.com/linux/v4.14.1/source/include/linux/mm_types.h#L429 https://elixir.bootlin.com/linux/v4.14.1/source/include/linux/lsm_hooks.h Stale: https://github.com/tiann/KernelSU/pull/2653 Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
105 lines
3.1 KiB
C
105 lines
3.1 KiB
C
#ifndef __KSU_H_KERNEL_COMPAT
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#define __KSU_H_KERNEL_COMPAT
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#include <linux/fs.h>
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#include <linux/version.h>
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#include <linux/cred.h>
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#include "ss/policydb.h"
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#include "linux/key.h"
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/**
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* list_count_nodes - count the number of nodes in a list
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* @head: the head of the list
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*
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* This function iterates over the list starting from @head and counts
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* the number of nodes in the list. It does not modify the list.
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*
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* Context: Any context. The function is safe to call in any context,
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* including interrupt context, as it does not sleep or allocate
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* memory.
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*
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* Return: the number of nodes in the list (excluding the head)
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*/
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#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
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static inline __maybe_unused size_t list_count_nodes(const struct list_head *head)
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{
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const struct list_head *pos;
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size_t count = 0;
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if (!head)
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return 0;
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list_for_each(pos, head)
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count++;
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return count;
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}
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#endif
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/*
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* Adapt to Huawei HISI kernel without affecting other kernels ,
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* Huawei Hisi Kernel EBITMAP Enable or Disable Flag ,
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* From ss/ebitmap.h
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*/
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#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)) && \
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(LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)) || \
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(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 14, 0)) && \
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(LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0))
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#ifdef HISI_SELINUX_EBITMAP_RO
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#define CONFIG_IS_HW_HISI
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#endif
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#endif
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// Checks for UH, KDP and RKP
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#ifdef SAMSUNG_UH_DRIVER_EXIST
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#if defined(CONFIG_UH) || defined(CONFIG_KDP) || defined(CONFIG_RKP)
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#error "CONFIG_UH, CONFIG_KDP and CONFIG_RKP is enabled! Please disable or remove it before compile a kernel with KernelSU!"
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#endif
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#endif
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extern long ksu_strncpy_from_user_nofault(char *dst,
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const void __user *unsafe_addr,
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long count);
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extern long ksu_strncpy_from_user_retry(char *dst,
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const void __user *unsafe_addr,
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long count);
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#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0) || \
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defined(CONFIG_IS_HW_HISI) || \
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defined(CONFIG_KSU_ALLOWLIST_WORKAROUND)
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extern struct key *init_session_keyring;
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#endif
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extern void ksu_android_ns_fs_check(void);
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extern struct file *ksu_filp_open_compat(const char *filename, int flags,
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umode_t mode);
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extern ssize_t ksu_kernel_read_compat(struct file *p, void *buf, size_t count,
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loff_t *pos);
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extern ssize_t ksu_kernel_write_compat(struct file *p, const void *buf,
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size_t count, loff_t *pos);
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extern long ksu_copy_from_user_nofault(void *dst, const void __user *src, size_t size);
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/*
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* ksu_copy_from_user_retry
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* try nofault copy first, if it fails, try with plain
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* paramters are the same as copy_from_user
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* 0 = success
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*/
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static long ksu_copy_from_user_retry(void *to,
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const void __user *from, unsigned long count)
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{
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long ret = ksu_copy_from_user_nofault(to, from, count);
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if (likely(!ret))
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return ret;
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// we faulted! fallback to slow path
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return copy_from_user(to, from, count);
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}
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
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#define ksu_access_ok(addr, size) access_ok(addr, size)
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#else
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#define ksu_access_ok(addr, size) access_ok(VERIFY_READ, addr, size)
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#endif
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#endif
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